To see the other types of publications on this topic, follow the link: Grinding machine stability.
Journal articles on the topic 'Grinding machine stability'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Grinding machine stability.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Epureanu, B. I., F. M. Montoya, and C. L. Garcia. "Centerless Grinding Systems Stability." Journal of Manufacturing Science and Engineering 121, no. 2 (May 1, 1999): 157–62. http://dx.doi.org/10.1115/1.2831199.
Full textAbstract:
In this paper, the steady state dynamics of a centerless grinding machine and work piece has been examined. A model of a centerless grinding system which allows both the deflection of the work piece center and the deformation of the grinding machine frame has been developed. Two instabilities are demarcated • work piece surface generation instability, and • grinding process instability. Both the generation and the grinding stability of self-excited vibrations are investigated. Stability limits are defined using the characteristic equations of the system. The main factors that influence the limit of stability of the machine, and the transversal profile of the work piece have been shown to be • the relative position of the grinding wheel, regulating wheel and support blade of the work piece; • the width of the grinding wheel; • the harmonic response of the grinding machine frame.
2
Leonesio, Marco, Giacomo Bianchi, and Nicola Cau. "Design criteria for grinding machine dynamic stability." Procedia CIRP 78 (2018): 382–87. http://dx.doi.org/10.1016/j.procir.2018.09.070.
Full text
3
Lei, Xiang Yang, Hao Huang, Shi Han Zhang, Jian Wang, Qiao Xu, and Yin Biao Guo. "A Novel CAM System with X/Y/Z 3-Axis Machines for Large Scale Aspheric Lens Grinding." Applied Mechanics and Materials 37-38 (November 2010): 23–31. http://dx.doi.org/10.4028/www.scientific.net/amm.37-38.23.
Full textAbstract:
According to needs of aspheric lens grinding and measurement with X/Y/Z 3-axis grinding machines, a CAM system is designed and implemented. The system, based on the parallel grinding geometry model, has realized the function of grinding locus planning, form error compensation, NC program auto-generation, on-machine measurement, grinding wheel on-machine measurement, simulation and technical database. To verify the stability of this CAM system, experiments were performed with three independent machining experiments. The experimental results indicate that the system realized the whole process of aspheric grinding, and it improved the machining efficiency and automation. Especially, this system adopted on-machine form error compensation technology and improved the machining accuracy. By implementing the error compensation integrated in the CAM system, the surface form error of a 430mm×430mm aspheric lens is decreased from PV8.2µm to PV4.1µm. The grinding accuracy was improved 100%.
4
Zheng, Y. G., W. G. Liu, Bin Jiang, Hang Gao, and S. G. Zheng. "Development of CBN Internal Grinding Machine for Precision Grinding of the Air-Conditioner Compressor Piston Hole." Advanced Materials Research 76-78 (June 2009): 43–48. http://dx.doi.org/10.4028/www.scientific.net/amr.76-78.43.
Full textAbstract:
According to the demand for internal grinding machine in precise machining of air-conditioner compressor piston hole, a kind of high precise CNC internal grinding machine with CBN wheel is developed by adopting self-adaptive control for grinding process. Meanwhile, grinding precision and stability are achieved by overcoming many problems emerging from high-speed grinding process with CBN wheel. More than 100000 times’ grinding experimental results show that the whole performance of grinding machine developed is the same as that of the same kind of international machine. In order to study grinding mechanism with CBN wheels and then improve machine’s capability, grinding data in several machining cycles is analyzed.
5
Han, Qing Kai, Tao Yu, Zhi Wei Zhang, and Bang Chun Wen. "Nonlinear Stability and Bifurcation of Multi-D.O.F. Chatter System in Grinding Process." Key Engineering Materials 304-305 (February 2006): 141–45. http://dx.doi.org/10.4028/www.scientific.net/kem.304-305.141.
Full textAbstract:
The nonlinear chatter in grinding machine system is discussed analytically in the paper. In higher speed grinding process, the self-excited chatter vibration is mostly induced by the change of grinding speed and grinding wheel shape. Here the grinding machine tool is viewed as a nonlinear multi-D.O.F. autonomous system, in which hysteretic factors of contact surfaces are also introduced. Firstly, the DOFs of the above system are reduced efficiently without changing its dynamic properties by utilizing the center manifold theorem and averaging method. Then, a low dimensional system and corresponding averaging equations are obtained. The stability and bifurcation of chatter system are discussed on the base of deduced averaging equations. It is proved that chatter occurs as a Hopf bifurcation emerging from the steady state at the origin of system. The theoretical analyses on the multi-DOF chattering system will lead to further understanding of the nonlinear mechanisms of higher speed grinding processes.
6
Saleh, Tanveer, and Mustafizur Rahman. "A System Development Approach for Electrolytic In-Process Dressing (ELID) Grinding." International Journal of Automation Technology 5, no. 1 (January 5, 2011): 21–29. http://dx.doi.org/10.20965/ijat.2011.p0021.
Full textAbstract:
This study aims to present the development and performance evaluation of an ultra-precision ELID grinding machine. The machine is a 3-axis machine, including three conventional linear axes (X,Y, andZ). On top, another rotational axis has been included to assist aspheric/spherical lens grinding. In order to introduce intelligence to the machine, several on-machine measuring systems have been developed and incorporated. In ELID grinding, pulsed DC voltage is applied to the metal-bonded diamond wheels to ensure the constant protrusion of sharp cutting grit throughout the grinding cycle. The peak dressing voltage is kept constant irrespective of the wheel sharpness in conventional ELID grinding, which may lead to over dressing of the grinding wheel. The grinding force ratio, also known asKvalue, is an indicator of grit sharpness. In this study, a new approach to wheel dressing is proposed: the peak dressing voltage is varied according to the change in theKvalue during grinding. In conventional ELID grinding, the duty ratio of the dressing power supply is kept constant throughout the grinding cycle. However, this method does not achieve grinding wheel truing, which is very important to maintaining the stability of the grinding. This research work proposes a novel approach to wheel truing by controlling the dressing voltage duty ratio for ELID grinding.
7
Zhang, Tao Chuan. "Design of Cemented Carbide Face Automation Grinder Based on Constant Force Grinding and Online Measurement Technology." Advanced Materials Research 712-715 (June 2013): 2742–46. http://dx.doi.org/10.4028/www.scientific.net/amr.712-715.2742.
Full textAbstract:
A set of face automation grinder is designed aimed at the cemented carbide characteristics of high hardness, high wear resistance, and good dimensional stability,and automatic grinding process is divided into three stages of coarse grinding,accurate grinding and light grinding; Constant force feed system is designed using servo drive mechanism and pneumatic mechanism; Using on-line measurement and grinding support institutions, the grinding process real-time monitoring and real-time processing size measurement are realized; With PLC as the central control unit automatic control system is designed for the grinding force control, measurement data processing and feedback show and grinding process control; The machine design idea is provided the references for other grinding machine automation design.
8
Hashimoto, Fukuo. "Dynamic Rounding Stability in Through-Feed Centerless Grinding." Inventions 5, no. 2 (April 29, 2020): 17. http://dx.doi.org/10.3390/inventions5020017.
Full textAbstract:
The through-feed method in centerless grinding allows manufacturers to produce cylindrical parts at much higher levels of productivity than can be achieved with in-feed grinding, so it has been extensively employed in industry. However, its rounding mechanism is not yet well understood due to the complexity of the through-feed process. This paper presents the fundamental parameters, such as material removal rates, forces, and so on in the through-feed grinding, and analyses on the grinding system with feedback loops, including regenerative functions and the machine dynamic functions. Further, the characteristic roots of the system, representing the number of waves and the growth rates of the harmonics in roundness, are identified at each grinding position from entry to exit. To evaluate the grinding process stability, a rounding stability index (RSI) was proposed. It was demonstrated that the analytical tool modeled in this paper can identify the optimum operational conditions by the RSI for achieving desired grinding productivity and accuracy. Finally, the model is verified with grinding tests, and the nm-order roundness obtained by the tests is shown.
9
Jiang, Zhuoda, and Yongyi He. "Research on Stability Prediction of the Crankshaft CNC Tangential Point Tracing Grinding." Mathematical Problems in Engineering 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/106159.
Full textAbstract:
As the key part of internal combustion engines, crankshaft with high efficiency and accuracy processing has always been the target of the engine manufacturer’s pursuit. Grinding is used to obtain the ultimate dimensional accuracy and surface finish in the crankshaft machining. Grinding of the main journals and the pin journals can be accomplished in a single clamping operation by CNC Tangential Point Tracing grinding technology. However, the chatter in the grinding process is harmful to the precision and surface quality. In this paper, stability lobe diagram is developed to predict the grinding chatter. First the dynamic model of Tangential Point Tracing grinding system is established. Then the limit formula of the critical grinding depth is calculated and the stability lobe diagram of the grinding system is presented. Finally, the validation experiments are carried out on the crankshaft grinding machine and the results are consistent with the calculation.
10
Zhao, Yong Qiang, Sheng Dun Zhao, and Hong Ling Hou. "Precision Grinding Process Design of Twin-Screw Compressor Rotor." Advanced Materials Research 774-776 (September 2013): 1107–11. http://dx.doi.org/10.4028/www.scientific.net/amr.774-776.1107.
Full textAbstract:
With the accuracy improvement of twin-screw compressor rotor machining, higher requirement of crew rotor grinded equipment and grinding process is put forward. Based the theory of screw grinding and CNC forming grinding wheel dress technology, the relationship between machine working parameters, CNC grinding wheel dressing parameters and screw rotor grinded process parameters are investigated, and the relationship between CNC grinding wheel dressing parameters and the screw rotor grinded process parameters is established, and its formulas are presented to describe the distances between grinding wheel axis and screw rotor axis. Through these formulas, the CNC wheel dressing program could be designed easily, the performance and efficiency of machine would be improved, and especially the machining quality of screw rotor would be enhanced and becomes more stability.
11
El-Wardani, T., M. M. Sadek, and M. A. Younis. "Theoretical Analysis of Grinding Chatter." Journal of Engineering for Industry 109, no. 4 (November 1, 1987): 314–20. http://dx.doi.org/10.1115/1.3187134.
Full textAbstract:
A mathematical model is proposed for the prediction of the grinding process chatter. It considers the machine structure as a multidegree of freedom system and takes into account various parameters affecting the process stability such as the workpiece and grinding wheel regeneration, wheel loading and its elastic characteristics. This model is based on a nonlinear relationship with the time factor which is introduced by the loading effect. Three-dimensional stability charts were predicted for the simultaneous variation of both the grinding wheel wear and loading. These stability charts relate the grinding wheel and workpiece speeds to the instantaneous limiting width of grinding. The validity of this mathematical model has been assessed with the aid of a series of chatter tests which were carried out in specially designed experiments. These tests show good quantitative and qualitative correlation between the theoretical results and those experimentally obtained. It has been found that the level of stability decreases with time, indicating the possibility of chatter occurring at a stable width of cut.
12
Wee Keong Neo, Dennis, Kui Liu, Rui Huang, and Hu Wu. "Edge Grinding Characteristics of Display Glass Substrate." Journal of Manufacturing and Materials Processing 5, no. 1 (March 1, 2021): 20. http://dx.doi.org/10.3390/jmmp5010020.
Full textAbstract:
Display glass substrate as a brittle material is very challenging to machine due to its excellent physical, mechanical, electrical, and optical properties such as high hardness, high strength, high wear resistance, good fracture toughness, good chemical stability, and good thermal stability. On the basis of Griffith fracture mechanics, our theoretical analysis indicated that edge grinding of the display glass substrate is under brittle mode when grinding with the given conditions, which was verified by the experimental studies of ground glass edge surface topography and fractured surface obtained. Grinding force (Fy) in the vertical direction was much larger than grinding force (Fx) in the horizontal direction, causing a large compressive stress acting on the grinding glass edge. Grinding torque was slightly increased with the increase of grinding speed. Grinding temperature was very high when measured under dry grinding compared with measurement under high-pressure coolant. Grinding of glass substrate edge was performed partially under ductile mode machining in the experimental conditions, which can be attributed to and contributed by those micro cutting edges generated by the fractured diamond grit on the grinding wheel surface.
13
Lajmert, Paweł, Małgorzata Sikora, and Dariusz Ostrowski. "A dynamic model of cylindrical plunge grinding process for chatter phenomena investigation." MATEC Web of Conferences 148 (2018): 09004. http://dx.doi.org/10.1051/matecconf/201814809004.
Full textAbstract:
In the paper, chatter vibrations in the cylindrical plunge grinding process are investigated. An improved model of the grinding process was developed which is able to simulate self-excited vibrations due to a regenerative effect on the workpiece and the grinding wheel surface. The model includes a finite-element model of the workpiece, two degrees of freedom model of the grinding wheel headstock and a model of wheel-workpiece geometrical interferences. The model allows to studying the influence of different factors, i.e. workpiece and machine parameters as well as grinding conditions on the stability limit and a chatter vibration growth rate. At the end, simulation results are shown and compared with exemplified real grinding results.
14
Deng, Xiao Lei, Jian Zhong Fu, Yong He, Zi Chen Chen, and Zhen Ya He. "Dynamic Characteristics Analysis of Precision Linear Rolling Guide CNC Grinding Machine Tool’s Bed." Applied Mechanics and Materials 37-38 (November 2010): 374–77. http://dx.doi.org/10.4028/www.scientific.net/amm.37-38.374.
Full textAbstract:
Bed is a main component of a large precision linear rolling guide CNC grinding machine tool Its dynamic characteristics impact on machine tool’s machining precision and stability directly. In this paper, boundary conditions on the bed of a machine tool factory’s production are analyzed. By using FEA method, the bed finite element models for dynamic analysis model are established and calculated. It provides guidance in investigating the effect factors of machining precision, the machine tool’s structure optimization and error compensation.
15
Huo, Meng You, Qin He Zhang, Jian Hua Zhang, and Xing Ai. "The Control System Construction of the Multifunctional Combined CNC Machine." Key Engineering Materials 315-316 (July 2006): 566–70. http://dx.doi.org/10.4028/www.scientific.net/kem.315-316.566.
Full textAbstract:
In this paper we present a multifunctional combined CNC machine that integrates the technology of USM, EDM and grinding. For non-conductive hard and brittle materials, the machine tool could perform ultrasonic machining and grinding machining combined ultrasonic vibration; for conductive hard and brittle materials, electrical discharge with or without ultrasonic vibration could be implemented. Conductive engineering ceramics have been used for elementary experiments, the results show that it is more efficient and more stable for processing this kind of materials by using the multifunctional combined CNC machine. On the basis of brief introduction about the structure of the machine tool, this paper emphasizes the form of control system, the gap state inspection that can be used to ensure the stability in processing and the principle for servo control.
16
Yang, Shu Ming, Yu Kun Xu, Lin Yang, Shi Long Liu, Hui Ying Zhao, Xing Yuan Long, and Zhuang De Jiang. "Optimization Analysis for Key Component of a Precision Optical Aspheric Grinding Machine." Advanced Materials Research 774-776 (September 2013): 158–63. http://dx.doi.org/10.4028/www.scientific.net/amr.774-776.158.
Full textAbstract:
Manufacture of ultra-precision micro-structured freeform surface relies on the high precision of machine tools. Precision, stability and repeatability of the Z-axis are the key factors of the high precision machine tools. The key component of the Z-axis is the ram, and its stiffness and stability have a crucial influence on the final precision. This paper demonstrated the structure optimization of the ram using finite element method based on ANSYS and the results were achieved to illustrate how the optimization variables affect the stiffness and deformation of the ram. Finally, the local three optimal design points were displayed and one of the most appropriate candidate points was chosen as the new design.
17
Jia, Lin, Yaonan Wang, Changfan Zhang, Kaihui Zhao, Li Liu, and Xuan Quynh Nguyen. "A Robust Adaptive Trajectory Tracking Algorithm Using SMC and Machine Learning for FFSGRs with Actuator Dead Zones." Applied Sciences 9, no. 18 (September 12, 2019): 3837. http://dx.doi.org/10.3390/app9183837.
Full textAbstract:
The actuator dead zone of free-form surface grinding robots (FFSGRs) is very common in the grinding process and has a great impact on the grinding quality of a workpiece. In this paper, an improved trajectory tracking algorithm for an FFSGR with an asymmetric actuator dead zone was proposed with consideration of friction forces, model uncertainties, and external disturbances. The presented control algorithm was based on the machine learning and sliding mode control (SMC) methods. The control compensator used neural networks to estimate the actuator’s dead zone and eliminate its effects. The robust SMC compensator acted as an auxiliary controller to guarantee the system’s stability and robustness under circumstances with model uncertainties, approximation errors, and friction forces. The stability of the closed-loop system and the asymptotic convergence of tracking errors were evaluated using Lyapunov theory. The simulation results showed that the dead zone’s non-linearity can be estimated correctly, and satisfactory trajectory tracking performance can be obtained in this way, since the influences of the actuator’s dead zone were eliminated. The convergence time of the system was reduced from 1.1 to 0.8 s, and the maximum steady-state error was reduced from 0.06 to 0.015 rad. In the grinding experiment, the joint steady-state error decreased by 21%, which proves the feasibility and effectiveness of the proposed control method.
18
Hashimoto, F., S. S. Zhou, G. D. Lahoti, and M. Miyashita. "Stability Diagram for Chatter Free Centerless Grinding and its Application in Machine Development." CIRP Annals 49, no. 1 (2000): 225–30. http://dx.doi.org/10.1016/s0007-8506(07)62934-5.
Full text
19
Cha, K. C., N. Wang, and J. Y. Liao. "Stability analysis for the crankshaft grinding machine subjected to a variable-position worktable." International Journal of Advanced Manufacturing Technology 67, no. 1-4 (September 30, 2012): 501–16. http://dx.doi.org/10.1007/s00170-012-4501-9.
Full text
20
Wu, Nan Xing, Fei Cheng, and Da Hai Liao. "Finite Element Contact Analysis and Life Analysis of Gears in the Double-Sided Grinding Machine." Applied Mechanics and Materials 778 (July 2015): 218–21. http://dx.doi.org/10.4028/www.scientific.net/amm.778.218.
Full textAbstract:
The contact fatigue life of gears has direct influences on the working life of the double-sided grinding machine, in the actual using process, the contact fatigue life of gears cannot meet the requirements of working because of many factors. This paper uses the finite element software ANSYS, establishs the two-dimensional model of gears, and analyzes and calculates it, the research shows that: life expectancy of gears is 2.13 years, so gears should have carburizing or carbonitriding heat treatment to fit process requirements, gears can live up to 5.82 years, it can fit the technological requirements of gear life of 5 years. It is some practical value for increasing the working life of the double-sided grinding machine and improving the stability and accuracy of the whole machine.
21
Wójcik, Ryszard, and Krzysztof Nadolny. "The effect of the grinding wheel modification on the state of the workpiece surface layer after internal cylindrical grinding of steel C45." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 231, no. 6 (June 23, 2016): 1162–73. http://dx.doi.org/10.1177/0954408916656887.
Full textAbstract:
Internal cylindrical grinding is one of the most difficult grinding processes due to the very long zone of contact between the grinding wheel and the workpiece surface. Such conditions limit delivery of the grinding fluid into the grinding zone, as well as impeding the removal of chips from it. As a result, during the internal cylindrical grinding process, difficult thermal conditions occur in the machining zone which finally could lead to grinding defects. One of the most efficient and cost-effective ways of improving the grinding stability and repeatability is modifying the grinding wheel structure. As such, modifications usually do not require interfering with the construction of the grinding machine or its equipment, they are universal and, possibly, widely applicable. This article presents a modified grinding wheel with helical grooves shaped on its active surface. Such modification was developed to reduce the thermal load of the workpiece surface and the occurrence of thermal defects. The effectiveness of the proposed grinding wheel modification was examined experimentally in the reciprocal circumferential internal cylindrical grinding process of 45C steel. The goal of the described tests was to determine the influence of the suggested grinding wheel modification on the condition of the workpiece surface layer (the surface roughness and residual stresses). The test results obtained indicated that application of the modified grinding wheel has a positive influence on the residual stresses in the workpiece surface layer, resulting in better delivery of the grinding fluid into the area of contact between the wheel and the machined material. Moreover, a decrease of the Ra parameter value by approximately 7–19%, as compared to the results of the process carried out with the (unmodified) reference grinding wheel was indicated.
22
Lu, Feng, Shi Chao Chen, Song Hua Li, Ke Zhang, and Yu Hou Wu. "The Inner Hole Grinding Surface Roughness Analysis of Zirconia Ceramics Electric Spindle." Key Engineering Materials 487 (July 2011): 99–103. http://dx.doi.org/10.4028/www.scientific.net/kem.487.99.
Full textAbstract:
The high-speed ceramic electric spindle is applied in high-speed NC machine tools. Each surface processing accuracy requirement of high-speed ceramic electric spindle is high. The inner hole surface roughness is the key factor which affects its high-speed stability and moving accuracy. This paper focuses on the research of the relationship between inner hole and grinding wheel granularity and grinding wheel linear velocity and transverse feeding and grinding camber ratio through the experiment of diamond wheel grinding the inner hole of ceramic spindle. The optimal grinding parameter combination of ceramic spindle inner hole grinding is obtained. The surface roughness of ceramic spindle inner hole reaches 0.21μm, through the analysis of orthogonal test. The results can completely satisfy the ceramic spindle high-speed operation requirements and enhance the ability of corrosion resistance and fatigue damage resistance. It then improves the whole work performance, reliability and life of ceramic spindle.
23
Zhao, Dong Xu, Shou Quan Hou, Jun Xi Bi, and Li Qin Wang. "Research and Development of CNC System of Screw Polishing and Grinding Machine Based on PMAC." Advanced Materials Research 462 (February 2012): 812–18. http://dx.doi.org/10.4028/www.scientific.net/amr.462.812.
Full textAbstract:
This paper introduces current situation of varying screw machining, characteristics of PMAC2-PCI, researches open CNC system based on PMAC2-PCI, designs CNC system of screw polishing and grinding machine, including hardware design and software design. The system holds the advantage of fast machining speed, high control precision and high stability.
24
Deng, Xiao Lei, Jian Zhong Fu, Yong He, Zi Chen Chen, and Hui Feng Jiao. "An Analysis of Thermal-Structural Characteristics for Precision Linear Rolling Guide CNC Grinding Machine Tool’s Bed." Applied Mechanics and Materials 37-38 (November 2010): 86–89. http://dx.doi.org/10.4028/www.scientific.net/amm.37-38.86.
Full textAbstract:
The bed is a main component of the large precision linear rolling guide CNC grinding machine tool. Its thermal-structure characteristics affect on machine tool’s machining precision and stability directly. In this paper, boundary conditions on the bed of a machine tool factory’s production are analyzed; using FEA method, the bed finite element models for thermal-structure coupling analysis are established and then calculated. By analysis, the simulation of the CNC machine tool operating conditions can effectively obtain the distributions of the bed temperature, thermal deformation and thermal stress; and the results are closed to the true situation.
25
Sira, Natalia, Antonina Kolohoida, Oleksandr Lytvyn, and Dmytro Kalchenko. "DEFINITION OF DYNAMIC CHARACTERISTICS GRINDING OF CYLINDRICAL AND NEEDLE ROLLER SURFACE OF A TEXTILE MACHINE." Technical Sciences and Technologies, no. 2(16) (2019): 44–53. http://dx.doi.org/10.25140/2411-5363-2019-2(16)-44-53.
Full textAbstract:
Urgency of the research. In the process of fabricating fabrics, various types of aggregates are used in the textile industry, such as crocheting, crocheting and others. Their working part is the drums and rollers covered with card headset. The quality of the work surface of the card headset is subject to high requirements, since the occurrence of an error in the craft drum or roller of the textile unit causes the formation of an uneven gap between the working elements and, accordingly, the release of the poor-quality product. And not a satisfactory condition of the working surface of the needles causes a gap in the material, which also increases the percentage of the gap. Target setting. Given the large dimensions of the drums and rollers of textile machines, as well as the slight stiffness of the headset, the dynamic impact on the accuracy of the processing has a significant impact. Actual scientific researches and issues analysis. Various aspects of the theory of fluctuations of rigid structures are investigated, which allows us to use an analytical approach to many practical cases. The main issues of the dynamics of metal-cutting machine tools are considered: equivalent and elastic systems, working processes, stability of the dynamic system, stationary and transitional processes. The data on the closed dynamical system of the machine, the indicators of dynamic quality are given. The methods of finishing a grinding of smooth cylindrical and sharpening of needle surfaces of drums and rollers of textile machines are offered. Uninvestigated parts of general matters defining. However, the study of dynamic characteristics in the process of finishing grinding cylindrical and needle surfaces of drums and rollers of textile machines was not conducted. Research of dynamic characteristics of the grinding process of cylindrical and needle surfaces of drums and rollers of textile machines, and determination of dynamic properties of elements of the processing system. The statement of basic materials. The value of the initial deflection of the needles as a result of their impact on the surface of the grinding wheel at the time of entry into the processing zone was determined. A spatial model of the needle was constructed and its frequency analysis in the Solidworks system was performed. Since the processing of textile rollers is proposed to be carried out on the grinding machine VZ-208F3, a modal analysis of its spindle assembly was also carried out. In the experimental study, the amplitude-phase-frequency characteristic is constructed. Conclusions. Through the computer spatial modeling, the first five self-oscillation frequencies were determined, as well as the corresponding oscillation patterns for the needle of the card headset and for the spindle knot of the machine VZ- 208F3. Experimental way is the amplitude-phase-frequency characteristic of the spindle.
26
Duan, Ji Hao, Yao Yao Shi, Xiao Jun Lin, and Ting Dong. "Flexible Polishing Machine with Dual Grinding Heads for Aeroengine Blade and Blisk." Advanced Materials Research 317-319 (August 2011): 2454–60. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.2454.
Full textAbstract:
The blade and blisk manufacturing includes polishing process when the surface roughness and size requirement of profile are disqualified after milling process. This polishing process is mainly carried out manually by skilled workers or NC machines. However, the existing polishing technology always leads to surface quality instability and inconsistency because of the complex free-form surface of blade and blisk. Therefore, in this paper, based on the research of polishing requirements and methods of blade and blisk, an automatic 6-axis polishing machine was proposed in order to enhance surface quality. And then, a polishing mechanism was designed using flexible technique to make the polishing tool accommodate surface waviness which was produced in milling process. In addition, the working principle and control method of flexible polishing mechanism were studied. Finally, the polishing test results of blade and blisk showed that the profile error was about 0.06mm and the surface roughness was less than Ra0.4 after automatic polishing. Compared with the manual polishing process, the automatic polishing technology not only increased the polishing efficiency and quality stability, but also reduced labor intensity largely.
27
Thompson, R. A. "On the Doubly Regenerative Stability of a Grinder: The Mathematical Analysis of Chatter Growth." Journal of Engineering for Industry 108, no. 2 (May 1, 1986): 83–92. http://dx.doi.org/10.1115/1.3187055.
Full textAbstract:
The growth of doubly regenerative chatter in a typical plunge cylindrical grinder is analyzed. The work is based on the mathematical method developed in reference [1]. Throughout, the physics of double regeneration is explained: (a) the individual contribution to chatter of wheel and workpiece regeneration is illustrated; (b) the wear resistant Borazon* wheel, although slightly more chatter prone, is shown to have an advantage over alumina because it requires less frequent dressing; and (c) the best in-process measure of grinding stability is shown to be wheel and workpiece lobe precession. The paper is concluded by showing how the optimum wheel and workpiece speeds are chosen. Under optimum conditions part tolerance and machine noise limit the maximum allowable grinding time and wheel wear establishes the dressing schedule.
28
Ignat’ev, A. A., V. A. Karakozova, and S. A. Ignat’ev. "Transfer function and margin of stability in the dynamic system of a grinding machine." Russian Engineering Research 35, no. 2 (February 2015): 123–25. http://dx.doi.org/10.3103/s1068798x15020094.
Full text
29
Subramanya Udupa, N. G., M. S. Shunmugam, and V. Radhakrishnan. "Workpiece Movement in Centerless Grinding and Its Influence on Quality of the Ground Part." Journal of Engineering for Industry 110, no. 2 (May 1, 1988): 179–86. http://dx.doi.org/10.1115/1.3187867.
Full textAbstract:
The grinding action and the rounding mechanism are highly complex in centerless grinding. The process geometry and the dynamic stability of the workpiece are critical factors affecting the quality of the ground parts. The workpiece, because of floating condition, has an inherent tendency to become unstable during grinding. This is particularly true in the case of hollow workpieces like bearing races, bushes, cylinder liners, etc. In this paper, an attempt has been made to investigate the dynamic instability of the workpiece and to identify its effects on the quality of ground parts in infeed grinding. The details of the experimental investigations carried out to measure the horizontal and vertical movements of the workpiece directly on the machine are included. Some measures to minimize the vertical movement of the workpiece and to improve the quality of the ground part are also discussed.
30
Leonesio, Marco, Giacomo Bianchi, and Hossein Safarzadeh. "Stability Analysis of Centerless Grinding with Loss of Contact Nonlinearity." EPJ Web of Conferences 224 (2019): 05007. http://dx.doi.org/10.1051/epjconf/201922405007.
Full textAbstract:
The paper presents a novel geometrical stability analysis of centerless grinding that takes into account the nonlinearity associated to wheel-workpiece detachment during lobes formation. Even though the rounding mechanism in centerless grinding has been studied since more than fifty years, stability analysis has been carried out applying stability criteria for linear systems (e.g., Nyquist) on a process model that neglects actual removal “clipping” due to wheel-workpiece detachment. This model limitation is usually overcome by considering only an integer number of lobes, supporting the restriction by the claim that a non-integral number of waves is less likely to build up since the waviness must be constantly removed and replaced by a succeeding wave, which is constantly moving around the workpiece. In this work, the nonlinearity entailed by removal clipping is explicitly taken into account and, by harmonic linearization, represented by a double input describing function (DIDF). Applying the Nyquist criterion on the resulting equivalent delayed system, the paramount instability associated to a quasi-integer number of lobes emerges naturally, without requiring additional assumptions. Moreover, it is shown that the nonlinearity due to wheel-workpiece detachment does not produce a limit cycle in a reasonable operation time. The results delivered by the proposed approach are verified by numeric simulations and positively compared to the relevant literature. The proposed formulation can be easily extended to consider also machine structure dynamics, thus increasing, even in this case, the accuracy of the stability analysis provided by the standard approach.
31
Sablin, Pavel, Alexander Kosmynin, and Vladimir Shchetinin. "Controlled spindle supports as a tool for ensuring machining quality." Proceedings of Irkutsk State Technical University 24, no. 5 (October 2020): 1019–29. http://dx.doi.org/10.21285/1814-3520-2020-5-1019-1029.
Full textAbstract:
The purpose of the work is to provide conditions for machined workpiece surface quality control based on the use of gas-magnetic supports in machine-tool systems (on example of the 3K227A internal grinding machine). To model the trajectory of tool and workpiece mutual movement the methods of nonlinear dynamics are used. The literature data on the problem are analyzed and experimental studies are carried out. Based on the considered issues of controlling the dynamic stability of technological systems under machining by means of contactless controlled gas-magnetic supports of spindle units, a scheme for adaptive control of the machine-tool system is proposed. It allows in many respects to eliminate external mechanical effects on the technological system, internal vibrations caused by drives and moving parts, as well as to compensate temperature deformations of the spindle unit frame and body. An adaptive control system based on gas-magnetic supports of the spindle assembly and the workpiece, as well as the control systems of the position of workpiece and tool (on example of 3K227A internal grinding machine) are demonstrated in action. The gas-magnetic support control system developed at Komsomolsk-na-Amure State Technical University makes it possible to set the position of the rotor axis with the accuracy of 0.1 microns. The study results obtained lead to the conclusion that the control of two adaptive links on the gas-magnetic supports, i.e., the spindle assembly of the tool and the spindle assembly of the workpiece, allows to achieve a rotation accuracy of up to 0.2 microns. The methods of nonlinear dynamics make it possible to construct an attractor (trajectory) of the tool tip movement in the real time, which provides a possibility to affect the input parameters of the machining process and thereby to control the output parameters. In addition to this, the control system of machine-tool system dynamic stability is applicable to other processing types as well, including edge cutting machining.
32
Popov, A. V. "Increasing the dimensional stability of diamond wheels for machine grinding of high-quality and art glass." Glass and Ceramics 67, no. 9-10 (January 2011): 319–21. http://dx.doi.org/10.1007/s10717-011-9288-x.
Full text
33
Kalchenko, Volodymyr, Dmytro Kalchenko, Volodymyr Venzhega, and Sergiy Ryabov. "ПІДВИЩЕННЯ ТОЧНОСТІ ТА ПРОДУКТИВНОСТІ ОБРОБКИ ТОРЦІВ РОЛИКІВ ПІДШИПНИКІВ КОЧЕННЯ." TECHNICAL SCIENCES AND TECHNOLOGIES, no. 3(17) (2019): 9–17. http://dx.doi.org/10.25140/10.25140/2411-5363-2019-3(17)-9-17.
Full textAbstract:
Urgency of the research. High-precision and productive machining of the ends of the rollers of the roller bearings is an urgent and important scientific and practical task, the solution of which will allow both to prolong the life of the bearings and to reduce their production, and therefore to increase the level of competitiveness of production. Target setting. The main requirements relating to the rollers of the rolling bearings are to ensure the high accuracy of size, shape, quality of end surfaces with high productivity of the machining process. Actual scientific researches and issues analysis. The main directions of improving the accuracy and productivity of two-sided grinding are to increase the rigidity of the machine-tool-tool-part system, to reduce the thermal impact, to improve the kinematic characteristics of the workpiece movement in the treatment area, to optimize the design and characteristics of grinding wheels. Uninvestigated parts of general matters defining. One of the most promising areas for improving the accuracy and productivity of the double-sided grinding process is to use the effect of crossing axes of grinding wheels and billets with special tool profiling. The purpose of the article. To analyze the factors that affect the accuracy and productivity of machining the end surfaces of parts on two-sided grinding machines and to develop a new high-performance method of processing the end surfaces of the rollers of the roller bearings, which would provide the possibility of assembly between the rolling bodies and the rings, not by a selective method. The presentation of the main material. The combined editing of the two planes of grinding wheels on two-sided grinding machines enables to obtain a larger diameter of the calibration section. In this case, the entire allowance is cut off in the area adjacent to the gauge. The calibration section at the inlet of the parts in the treatment area does not participate in cutting off the seam allowance, has high stability and at the outlet forms the final accuracy of the end surfaces. Conclusions and suggestions. The paper proposes a new high-performance method of single-pass machining of the end surfaces of the rollers of the roller bearings on two-sided grinding machines with oriented grinding wheels, which have a calibration section, which ensures high accuracy of processing. This method allows to reduce the scattering range of sizes and to go to the method of complete interchangeability when assembling the bearing units.
34
Harrison, A. J. L., and T. R. A. Pearce. "Prediction of lobe growth and decay in centreless grinding based on geometric considerations." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 216, no. 9 (September 1, 2002): 1201–16. http://dx.doi.org/10.1243/095440502760291763.
Full textAbstract:
The growth and decay of lobes during centreless grinding have been studied by previous researchers using physical tests, time-domain simulation and identification of the roots of the Laplace transform of the characteristic equation. In this paper, the authors have extended these latter two methods to generate complete stability diagrams encompassing the entire practical range of machine set-up angles. These diagrams indicate that by varying the set-up angles in a prescribed manner during grinding, rapid rounding of arbitrarily lobed components can be achieved. This is verified via time-domain simulation. Secondly, a novel and arguably more intuitive method of predicting the lobe growth and decay during centreless grinding is presented. The method considers the locations of the three points of contact between a lobed workpiece and the regulating wheel, the support plate and the grinding wheel. Axial symmetry is assumed. A unique circle can be drawn through these three points. The centre and radius of this circle vary continually as the workpiece rotates, in a manner dependent upon the workpiece's profile and the set-up angles. An above-average instantaneous radius leads, via machine stiffness, to a correspondingly larger grinding force and so to an increased instantaneous depth of cut. If this occurs when the trough of a lobe is being ground, the trough will become deeper and lobe growth will result. By contrast, if the instantaneous radius is below average when the trough is being ground, the lobe will decay. From this simple geometric consideration, the authors have calculated the rates of decay and growth of a range of numbers of lobes, across a wide range of set-up angles. The results are shown to agree well with those given using the previous methods.
35
Grigoriev, Sergey N., Alexey B. Nadykto, Marina A. Volosova, Alexander A. Zelensky, and Petr M. Pivkin. "WEDM as a Replacement for Grinding in Machining Ceramic Al2O3-TiC Cutting Inserts." Metals 11, no. 6 (May 28, 2021): 882. http://dx.doi.org/10.3390/met11060882.
Full textAbstract:
Small-size cutting inserts for assembly cutters are widely used to manufacture a variety of parts for the aerospace, automotive and mechanical engineering industries. Due to their high hardness and chemical stability, cutting Al2O3-TiC ceramics significantly outperform hard alloys in machining heat-resistant and difficult-to-machine materials. However, grinding on CNC machines, the most common technology for manufacturing ceramic inserts, is associated with numerous issues when it comes to manufacturing small-size cutting inserts. For example, high cutting forces and high grinding wheel wear rates cause a rapid loss of dimensional accuracy and deterioration of the quality of the surface being machined, while the interference of the grinding wheel with the surface being treated imposes serious limitations on the geometry of the small-size ceramic inserts to be grinded. Here we show that Wire Electrical Discharge Machining (WEDM), which is a contactless and, thus, a more flexible method in terms of the size and geometrical properties of a workpiece to be machined, can be used as a replacement for grinding operations in machining small ceramic inserts. A composite of 70% aluminum oxide and 30% titanium carbide was chosen as a ceramic material because a further increase in the TiC fraction causes a marked decrease in wear resistance, while its decrease results in an undesirable loss of electrical conductivity. While in order to replace grinding with WEDM, WEDM has to be stable in the sense of occurring without frequent wire breakages, achieving WEDM stability is not an easy task due to the low electrical conductivity of Al2O3-TiC ceramics and high operational temperatures, which promote the diffusion of dielectric and electrode products in the surface layer of the cutting inserts being machined. These factors may lower the quality of the final product due to damage to the insert surface, marked increases in the roughness RA and in diffusion in the surface layer, which increases the friction coefficient and, hence, reduces the life of the manufactured cutting inserts. We have increased stability of the WEDM process by identifying and applying rational process conditions that lead to a reduced, by a factor of 2.63, roughness Ra and also a reduced, by a factor of 1.3, depth of craters. Performing a chemical and structural analysis, we found that the application of high energies combined with an increasing interelectrode gap (IG) (technological parameter SSol, a complex indicator that determines the speed of the wire electrode depending on the number of pulses per unit of time and the IG size, is set at 80, EDM3 technology) causes increased surface damage and contamination, while a small IG (SSol = 45, EDM1 technology) reduces the material removal rate due to contamination of the working zone between the surface being machined and the electrodes. After reducing the IG by lowering SSol from 80 to 45, the roughness Ra of 0.344 µm was achieved, which allows for replacing grinding operations with WEDM in machining hardening chamfers, front surfaces and, to a lesser degree, the rear and support surfaces of cutting inserts. In this case, when the IG is reduced to SSol = 45, the electroerosion products in the dielectric promote local breakdowns, which in turn produce a large number of deep craters which adversely affect the performance of cutting inserts. However, we found that a slight increase in SSol from 45 to 55 (EDM3 technology) significantly reduces the number of craters and lowers their depth from 50 μm to 37 μm. Although in this case the roughness grows to 0.534 μm due to increased discharge energy, the improved flushing of the IG and the reduced occurrence of local high-temperature breakdowns—evidenced by a decrease in the depth and number of deep craters formed due to current localization during short circuits—significantly reduced contamination of the surface layer and the crater formation rate. Therefore, WEDM can be recommended for use in machining reinforcing chamfers and, to a lesser degree, front surfaces. These considerations lead us to conclude that WEDM is a viable alternative to grinding in machining Al2O3-TiC ceramic cutting inserts of a small size and a complex shape, and that its application to manufacturing cutting inserts from poorly conductive cutting ceramics should be studied further.
36
Holešovsky, Frantisek, Radek Lattner, Martin Novák, and Milan Dian. "The Formation and Behaviour of Residual Stresses with Finished Surfaces." Key Engineering Materials 686 (February 2016): 63–67. http://dx.doi.org/10.4028/www.scientific.net/kem.686.63.
Full textAbstract:
The single tool grains affect the workpiece surface during grinding in the separated areas of deformation. The elastic and consequently plastic deformations occur at the engagement of grains. The friction of grain and material likewise the friction of elementary chip and grain acts simultaneously. These phenomena are accompanied with an origination of great amount of heat and high pressures and that is the reason for residual stress origin and formation in the ground surface. The residual stress is an important factor in influencing usable properties of machine parts. The stress influences not only the dynamical load capacity of surface but the durability and quality of design units as well. This stress is considered as the source of so called technological notches, having an influence on corrosion resistance, wear resistance, and dimension stability of machine parts.
37
Xu, Ying Shuai, Ping Zou, Xu Lei Yang, and Yu He. "Study on Ultrasonic Generator for Ultrasonically Assisted Machining." Advanced Materials Research 797 (September 2013): 320–25. http://dx.doi.org/10.4028/www.scientific.net/amr.797.320.
Full textAbstract:
Ultrasonic vibration cutting can be widely used in lathe, planer, milling machine, grinding machine, thread processing and gear processing, etc. Ultrasonic vibration cutting system is composed mainly of ultrasonic generator, ultrasonic transducer, luffing rod, cutting tool, etc. Here, ultrasonic generator is the most important. The stand or fall of signal, which is produced by ultrasonic generator, has direct influence on anticipated effect and ability of ultrasonic machining. In order to generate a signal, which can be suitable for ultrasonic machining, ultrasonic vibration cutting system is studied, and ultrasonic signal generator based on direct digital frequency synthesis (DDS) is designed and conducted a cutting test with this ultrasonic machining system. The results show that the signal generator, which is made up by DDS technology, can generate the signal with stability, reliability and greater flexibility, and can be fully applicable to the ultrasonic machining.
38
Huliieva, N. M., D. O. Somov, V. V. Pasternak, L. M. Samchuk, and T. I. Chetverzhuk. "The Selection of Boron Nitride Circles for Grinding Saponite–Titanium Composites Using Non-Parametric Method." Latvian Journal of Physics and Technical Sciences 57, no. 6 (December 1, 2020): 53–64. http://dx.doi.org/10.2478/lpts-2020-0033.
Full textAbstract:
AbstractThe issue of grinding saponite–titanium composites has not been considered in the machine building industry yet. The reason is that the chips are stuck on the working surfaces of abrasive tools made of silicon carbide and electrocorundum. This is due to the high adhesive activity at operating cutting temperatures between the composite and traditional abrasives.The article aims at studying the grinding of saponite–titanium composites using abrasive tools in various cutting modes based on parametric and non-parametric statistical methods.To solve this problem, high porous wheels (HPW) made of cubic boron nitride CBN30 with 100 % concentration on a bond V (K27), a pore-forming KF40, varied grains: B76, B126, B151 (ISO 6106:2013) – and hardness: M and O (ISO 525:2013) were used to grind saponite–titanium composites. Additionally, the Norton wheels from green silicon carbide with a normal porosity 39C (46; 60) K8 VK and with different grain size were tested. Norton wheels provide reduction of roughness height by 1.4–1.5 times in comparison with boron nitride HPW. These are recommended for the finishing grinding stage and HPW CBN30 – the preliminary to reduce the thermal effects on composites. By processing stability, the Norton wheels with grain 46 rank first, and among boron nitride HPW – CBN30 B76 100 OV K27–KF40.
39
Deng, Bing, and Guo Qiang Shen. "The Application of Fuzzy PID Control Algorithm in Variable Frequency Speed Regulation System of Glass Edge Grinding Machine." Applied Mechanics and Materials 697 (November 2014): 151–55. http://dx.doi.org/10.4028/www.scientific.net/amm.697.151.
Full textAbstract:
Aiming at the deficiencies of traditional PID control algorithm, the application of Fuzzy PID control algorithm is proposed in variable frequency speed regulation system of glass edge grinding machine. The design of fuzzy PID controller is presented in the paper. The paper not only introduces the system principle and models for inverter and AC asynchronous motor but also tells the principle of Fuzzy PID Controller and its design method. A simulation model including traditional PID Controller and Fuzzy PID Controller is established in MATLAB/Simulink. Through the analysis of the difference between the two controlling outputs, the better performance of Fuzzy PID Controller in response speed, accuracy and stability is proved effectively. The result can be used as important criterion to the practical application of Fuzzy PID control algorithm.
40
Kim, In-Woo, and Choon-Man Lee. "Study on Structural and Stability Analyses of the Main Parts of a High-Precision Grinding Machine Considering the Cutting Force." Journal of the Korean Society for Precision Engineering 32, no. 8 (August 1, 2015): 693–98. http://dx.doi.org/10.7736/kspe.2015.32.8.693.
Full text
41
Zhao, Li Jie, De Cheng Yuan, and Jian Tang. "Ball Mill Load State Recognition Based on Kernel PCA and Probabilistic PLS-ELM." Applied Mechanics and Materials 263-266 (December 2012): 398–401. http://dx.doi.org/10.4028/www.scientific.net/amm.263-266.398.
Full textAbstract:
Operating condition recognition of ball mill load is important to improve product quality, decrease energy consumption and ensure the safety of grinding process. A probabilistic one-against-one (OAO) multi-classification method using partial least square-based extreme learning machine algorithm (PLS-ELM) is proposed to identify the operating state of ball mill. The feature of shell vibration spectrum is extracted using KPCA. PLS-ELM model is applied to enhance the reliability and accuracy of the operating conditions identification of the ball mill load. Posterior probability of each class using Bayesian decision theory is defined as a measure as classification reliability. Classification results of the experimental ball mill shown that the accuracy and stability of the proposed method outperform ELM, PLS-ELM and KPCA-ELM model.
42
Klapiszewski, Łukasz, Karol Bula, Marta Sobczak, and Teofil Jesionowski. "Influence of Processing Conditions on the Thermal Stability and Mechanical Properties of PP/Silica-Lignin Composites." International Journal of Polymer Science 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/1627258.
Full textAbstract:
Functional silica-lignin dual fillers were obtained via mechanical grinding of the components (Syloid 244 silica and kraft lignin). Of particular importance here is the fact that lignin is a natural polymer and particularly that it is a waste by-product of paper production, whose recycling is highly desirable. The product underwent comprehensive dispersive-morphological and thermal analysis. SiO2-lignin hybrid fillers were also used in polypropylene-based composites, extruded via corotating a twin screw machine with different screw speeds. The thermogravimetric data obtained for the extrudates confirmed that the application of the lignin into PP produces a significant char residue. Addition of silica to lignin via this new hybrid formulation has a positive effect on the thermal stability of PP/silica-lignin composites, which can be seen even when observing the temperature for the maximum rate of weight reduction. Tensile test results show that the addition of silica by means of dual filler incorporation improves the mechanical parameters in comparison with pure PP and PP/lignin composite.
43
Qi, Xiaole, Guohe Li, Qi Zhang, and Fei Sun. "A Review on the Finite Element Modeling of the Particle Reinforced Metal Matrix Composites in Cutting Process." Recent Patents on Engineering 14, no. 1 (June 21, 2020): 39–55. http://dx.doi.org/10.2174/1872212113666191001223709.
Full textAbstract:
Background:: Particle Reinforced Metal Matrix Composites (PRMMCs) are widely used because of the higher specific strength, better dimensional stability, lower thermal expansion coefficient, better wear and corrosion resistance. However, the existence of reinforcing particles makes it hard to machine. The main manifestations are as follows: severe tool wear, easy generation of debris tumors in processing, and many defects on the machined surface, etc. These seriously limit its wider application. The Finite Element Method (FEM) has been widely applied in the research of PRMMCs machining according to recent patents, which can improve the efficiency and reduce the cost of research. Therefore, it is necessary to carry out a deep research for the processing technology of PRMMCs. Methods:: In this paper, the latest research progress of finite element simulation of cutting PRMMCs was summarized. The key technologies of finite element simulation, including constitutive model, geometric model, friction model between chip and tool, fracture criterion and mesh generation, are comprehensively analyzed and summarized. The application in the specific processing methods was discussed, such as turning, milling, grinding, ultrasonic vibration grinding and drilling. The existing problems and development direction of the simulation of PRMMCs cutting are also given. Besides, a lot of patents on finite element simulation for PRMMCs machining were studied. Results:: Finite element model for the actual composition determines the accuracy of finite element simulation. Through the secondary development of finite element software, a more realistic finite element model of Particle reinforced metal matrix composites can be established. Conclusion:: Finite Element Method (FEM) provides a new approach for the study of mechanism of Particle reinforced metal matrix composites machining. Quantitative analysis and prediction of micro- details in cutting can be realized.
44
Li, Zhenyuan, Yimin Zhang, Changyou Li, and Zhi Tan. "Dynamic and Stability Analysis of Multibolt Plane Joints under Normal Forces." Applied Sciences 9, no. 24 (December 15, 2019): 5521. http://dx.doi.org/10.3390/app9245521.
Full textAbstract:
In this paper, a stiffness model of contact surfaces based on a modified three-dimensional fractal contact model is built, which is in accordance with the experiment results. Additionally, the static, dynamic, and stable behaviors of the bolt joint between the spindle box and the machine bed are analyzed. The mathematical relationship between fractal parameters of the surface topography and the stiffness of the system was established to accurately study its static behaviors. Asymmetric curves are observed from the load–deflection results and the nonlinear stiffness characteristic is also presented. It is shown that both the stress and the stiffness increase with the increase of the displacement near the static equilibrium position. Meanwhile, a simplified model without the consideration of roughness is compared with joint interfaces composed from milling, scraping, and grinding surfaces. Numerical calculation was employed to investigate effects of design parameters on the system under harmonic excitation when the processing method, excitation force, bolt pre-tightening force, topography parameters, and other structural parameters, i.e., nominal contact area, joint thickness and bolt number, are eventually regarded as the control parameters. The aim of the article is to analysis the influence of these parameters, including surface morphology, on nonlinear characteristics of the bolt interface with fractal contact surfaces andto provide some references to improve the characteristics.
45
Jubayer, MF, MB Uddin, and MO Faruque. "Standardization parameters for production of tofu using WSD-Y-1 machine." Journal of the Bangladesh Agricultural University 11, no. 2 (August 10, 2014): 307–12. http://dx.doi.org/10.3329/jbau.v11i2.19930.
Full textAbstract:
The present work was aimed to standardize different parameters for tofu production using the WSD-Y-1 machine. For this purpose the coagulant variation for production of tofu, shelf life of produced tofu as well as capacity of different parts of the WSD-Y-1 machine was determined. Soybean sample was collected from the Givency Pvt. Ltd., Gazipur. Soymilk was prepared by using the WSD-Y-1 machine. Seven tofu samples were prepared by using different coagulants (CaSO4, MgSO4). TSS variation of the milk was also made. The storage stability of tofu was observed at both room temperature and refrigeration temperature. The yield of tofu varied with coagulants. It was observed that the calcium sulfate gave more yield than magnesium sulfate when the use of both of the coagulants exceeded the single use. Tofu can be kept fresh under water up to one and half of a day and in the refrigerator up to ten days. The operating system of the WSD-Y-1 machine was standardized carefully. There were three operating parts: grinding, heating, and pressing. The grinder was capable to grind about 12-13 kg soybeans at a time. About 45 liter of milk can be heated in the heating system while in the pressing system about 14 liter of milk can be kept for pressing at a time. In this experiment about 1.2 kg of tofu was produced from 1 kg of soybean. On the basis of the work it is recommended that good quality of tofu can be prepared by using the WSD-Y-1 machine which is superior in quality to the hand-made ones. DOI: http://dx.doi.org/10.3329/jbau.v11i2.19930 J. Bangladesh Agril. Univ. 11(2): 307-312, 2013
46
Wang, Jianxi, Zhiqiang Ren, Jinjie Chen, and Long Chen. "Study on Rail Profile Optimization Based on the Nonlinear Relationship between Profile and Wear Rate." Mathematical Problems in Engineering 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/6956514.
Full textAbstract:
This paper proposes a rail profile optimization method that takes account of wear rate within design cycle so as to minimize rail wear at the curve in heavy haul railway and extend the service life of rail. Taking rail wear rate as the object function, the vertical coordinate of rail profile at range optimization as independent variable, and the geometric characteristics and grinding depth of rail profile as constraint conditions, the support vector machine regression theory was used to fit the nonlinear relationship between rail profile and its wear rate. Then, the profile optimization model was built. Based on the optimization principle of genetic algorithm, the profile optimization model was solved to achieve the optimal rail profile. A multibody dynamics model was used to check the dynamic performance of carriage running on optimal rail profile. The result showed that the average relative error of support vector machine regression model remained less than 10% after a number of training processes. The dynamic performance of carriage running on optimized rail profile met the requirements on safety index and stability. The wear rate of optimized profile was lower than that of standard profile by 5.8%; the allowable carrying gross weight increased by 12.7%.
47
Kaestle, Christopher, Aarief Syed-Khaja, and Joerg Franke. "Investigations on the Wire Bonding Capability on Selective Laser Melted Structures." International Symposium on Microelectronics 2016, no. 1 (October 1, 2016): 000209–13. http://dx.doi.org/10.4071/isom-2016-wa43.
Full textAbstract:
Abstract The paper displays the influencing factors, as well as the possibilities and challenges that come along with the process combination of selective laser melting (SLM) and heavy wire bonding. For the investigations, test samples were created from bronze powder on a SLM-machine. Then, 300 μm aluminum and copper wires were bonded on the SLM generated structures. Wire bonding capability is analyzed on untreated as well as on post-processed surfaces. The influence and effectiveness of various steps of post-processing such as cleaning, sandblasting and grinding are analyzed. Thus, interdependencies between both manufacturing process as well as the post-processing can be revealed. The effect of surface roughness and hardness of the assembly partner are investigated as well. To draw statistically backed conclusions, all tests are performed using DoE (Design of Experiment) studies. The primary characteristics besides the bond parameters that influence the wire bonding capability are focused in this paper. The process stability as well as the interconnection quality are evaluated by optical non-destructive laser microscopic analysis. Destructive pull and shear tests and metallographic cross sections are performed to evaluate the adhesion characteristics. The process stability and the yield obtained are important factors to describe the process and to evaluate the industrialization potential. By a profound understanding of all interdependencies between the two processes, a flexible manufacturing technology for power devices can be established.
48
Tokarchuk, Oleksіі, and Igor Kupchuk. "RESEARCH ON INFLUENCE OF CONSTRUCTIONS SIZES OF THE INTAKE AND CALIBRATION SURFACE OF CHIPLESS TAPS FOR THE PROCESS OF EXTRACTION OF THREAD." Vibrations in engineering and technology, no. 3(98) (October 30, 2020): 76–84. http://dx.doi.org/10.37128/2306-8744-2020-3-8.
Full textAbstract:
The analysis of modern existing methods for producing internal thread showed that one of the most promising methods, with significant technological capabilities and high productivity, is the method of plastic shaping (extrusion) of the thread with chipless taps. The complex of known measures aimed at increasing the stability of taps and their reliability, consisting in the creation of new tool materials, improvement of the design and optimization of the geometry of the cutting part of the taps, improvement of the quality of working surfaces, the use of new types of cooling and optimal settings, do not solve the final issue of high performance and high quality manufacturing of thread holes in stainless and heat-resistant steels not only on highly automated equipment, but even on conventional ones. It is substantiated that the most widespread are taps with a conical full-profile intake part; distortion of the pitch ΔР at he tops of the turns in the transition zone is one of the main design disadvantages of chipless taps. A diagram of the formation of a thread profile by chipless taps with a conical deformation pattern is presented. It is proved that the geometric incompatibility between the thread profile of the tap and the thread formed by it is one of the main reasons for the chipping of the tops located in the transition zone and a sharp increase in the torque of the thread extrusion The parameters of chipless taps are optimized and the advantages of their use in the process of thread extrusion are determined. The main objectives of the research: to investigate the power features of the process of manufacturing threaded holes with chipless taps in stainless steel parts in order to develop optimal designs of taps for through and blind holes; to develop a technological process for the manufacture of chipless taps of the necessary technological equipment for a grinding machine, as well as for grinding the threaded profile of taps.
49
Wegener, Konrad, and Atsushi Matsubara. "Special Issue on Advanced Material Driven Design of Machine Tools." International Journal of Automation Technology 14, no. 2 (March 5, 2020): 261–63. http://dx.doi.org/10.20965/ijat.2020.p0261.
Full textAbstract:
The design of machine tools strongly depends on the materials chosen. Increasing requirements on machine tools require the joint optimization of material and design and thus also drive the development of new materials in this field. Digital technologies finally creating a digital shadow of the machine in development also enable the required co-development taking into consideration dynamic, thermal and long term influences and behavior, enabling state and health monitoring to increase the performance of the machine tool to the maximum possible. The choice of material for the different components of machine tools is today even more difficult than ever. The recent review paper by Möhring et al. [1] sheds light on the vast field of properties and decision opportunities of combining materials at hand with design features. In former times, cast iron was the predominant material for machine bodies and has left its footprints on the design of machine tool bodies lasting still up to now. Because massive machine bodies have been the wealth of good properties, high accuracy, stiffness, good material damping properties have been attributed to cast iron design, then with increasing strength requirements higher strength cast irons came into fashion having much less material damping and finally lead to welded frames. Today requirements of dynamics and thermal behavior change the scene again. The goal is to achieve high productivity with high accuracy, which typically is a contradiction. But increasing dynamics requires distinguishing between moving bodies and their non-moving counterparts, and opens the floor for multimaterial design. For moving parts, which have to move with high dynamics meaning, high speed, high acceleration, high jerk, light weight design prevailed with the utilization of standard materials. Because manufacturability plays a major role, the bionic structures have to be degraded to thin walled rib structures as demonstrated in Fig. 1, while in future additive manufacturing will remove that restriction and enable some real bionic structures. Furthermore material choice has a huge impact on inertia savings which opens the door for CFRP, which becomes especially interesting, when the anisotropy of this material is exploited as shown in Fig. 2. From the manufacturability truss structures then result shown in Fig. 3. For the nonmoving elements, the base body, cast iron, welded steel, polymer cast, and concrete are typical materials chosen. Also aluminium structures are discussed despite the fact that aluminium has only one third of the stiffness of steel, but it offers much better thermal conductivity equalizing temperature differences faster and thus reduces the warp of the structure, which typically causes larger errors than an isotropic thermal expansion. For the choice of materials no generalizable guideline exists. The question which material is the better choice is not answerable in generality, because design follows material, which means that a sound comparison requires completely new design approaches for the different materials, where the difference between metal and polymer concrete or CFRP is really large, offering different potentials. As an example, a design of a fast moving bridge of a gantry machine might be considered. The guiding of a support on this bridge with roller guidings imposes severe problems to the design due to the material mix and different thermal expansion coefficients. Thus the choice of CFRP for the bridge necessarily must be followed up by a decision of the guiding principle, where in this case aerostatic bearings were considered as the most promising possibility. Also the potentials for function integration into the material are of major interest for the material choice, as this is easily possible for low temperature castings like for mineral cast, CFRP, or concrete. This integration of functionalities actually is a fairly new approach and relates again the machine body design to inspiration from biology, as for instance trees or leaves are from the point of view of materials weaker than our technical materials, but have a fine integration of functionalities as transmittance of information and nourriture. Sensor integration opens the field for “feeling machines” also inspired from biology, which enables the machine to detect its embedding environment and react accordingly. Cheap and miniaturized sensors are on the other side the developments that enable this approach of machine design. In the age of compensation, Industrie 4.0 and biological transformation, this functional integration will have a huge impact on material choice. Also in terms of thermal issues in machine tools, the material choice plays a major role, as thermal elongation is a physical property which is influenced by material choice. A much larger influence comes from design as indicated already above. With growing importance of compensation besides sensor integration, especially the thermal linearity and reproducibility are of crucial importance, which makes multi material design a non-trivial design task. The discussion on the superiority of thermally fast reacting machines or thermally slow reacting machines has not come to an end yet. Problematic are machines composed of components that react fast and those that react slow. A major step in that direction is the discovery of thermal resonances in [5], which shows that temperature change frequencies can depending on the machine design lead to higher or lower thermal displacements of the TCP and therefore need to be taken into account in the design phase and are significantly influenced by the choice of materials. Restrictions and influences are also coming from the process a machine tool has to enable. The material choice must take into account the influence of different media as for instance the metal working fluids as well as the debris like hot chips etc. The aforementioned discussion is mainly a discussion of main structural parts of machine tools. It must be pointed out that a machine tool is more than the sum of its structural elements, as also covers, which typically get forgotten in all academic discussion of behaviors of machine tools, but are significant for the influence of the environment on the machine tool. Also here the material choice plays a major role. Finally material choice to a large extent decides on the costs of a machine tool, but due to the huge amount of influence factors a sound fact based decision requires a nearly full design elaboration of various material choices and the summation of costs at the end of this process. This special issue with its various individual papers elucidates different aspects of the influence of materials on the design of machine tools without being capable of offering clear rules for material choice. ===danraku===1) Isolating material to exclude environmental influences on machine tools is proposed. ===danraku===2) A new guiding system with rollers and sliding guidings is proposed and the different materials for the sliding part are investigated. ===danraku===3) Gears from bamboo fibres are proposed and the manufacturability as well as their performance are discussed. The gears offer great advantages from the environmental point of view. ===danraku===4) CFRP for spindle shafts is evaluated and CFRP spindles are compared with steel spindles within the same geometric boundary conditions. The performance increase in compliance and thermal stability is significant. ===danraku===5) A topological optimization of a grinding machine tool structure is presented and showed drastically increased performance. The difficulty to transfer it to a mass producible machine tool structure is pointed out. ===danraku===6) A design of a CFRP ram for a high speed stamping press is presented and testing procedures to ensure the ability of the ram to withstand billions of impacts are designed and carried out. ===danraku===7) CFRP can beneficially applied for the cutting tool structure and besides enhancing dynamics in terms of mass and damping the material also is a valuable basis for smart tools. There are good arguments for each of the materials, which cover the whole scope of machine tool functionality: manufacturability, stiffness, strength, specific mass, thermal properties, function integrability, reproducibility, availability, environmental friendliness, and costs.
50
Pradoto, Rani, Eliza Puri, Tri Hadinata, Qinthara D. Rahman, and Ryan Muhammad Az-zuchruf. "Improving Strength of Porous Asphalt: A Nano Material Experimental Approach." Jurnal Rekayasa Sipil (JRS-Unand) 15, no. 2 (December 1, 2019): 75. http://dx.doi.org/10.25077/jrs.15.2.75-89.2019.
Full textAbstract:
Porous asphalt (PA) has potential to be utilized in many urban area in Indonesia which often faced high street runoff during rainy season. PA can be a solution for storm water management. A typical porous pavement has an open-graded surface over an underlying stone recharge bed. The water drains through the porous asphalt and into the stone bed, then, slowly, infiltrates into the soil. However, despite of the benefit of porous asphalt, there is still weaknesses, such as less of service life than dense-graded asphalt due to its lower durability and strength. In order to improve durability and strength of PA, this study investigates the effect of utilizing fly ash (FA) class F in porous asphalt (PA) mixture as replacement in aggregate gradation and perform as filler. Mechanical activation (grinding) of fly ash was performed resulting in reduction of particle size. This material gives more strength since the more of surface area that can bind in finer particle size. Utilizing fly ash into nanomaterial is one of the methods for this study. Material approaches for nanomaterial were proposed by breaking up larger particles with physical processes such as grinding or milling. This is called mechanical activation. Since asphalt pen 60/70 is mainly binder material in Indonesia, it is used as the default for all samples in this experiment. The optimum bitumen content (OBC) was determined for all the mix by Marshall mix design. In view of the nanomaterial approach, samples were then prepared for the same optimum bitumen content (5.85%) by using Bina-Marga’s PA standard in control mix as well as natural FA and modified FA as alternative filler in modified mixes. modified FA itself has been milled using transversal ball mill machine for 3 to 6 hours. This experimental study indicated higher stability value and reduction of permeability with the same OBC for the mixture having modified FA as filler content in comparison with standard mix and natural FA mix. All sample conformed with Indonesian asphalt porous Specification. This trends will become as a starting point for improvement in the future research. For further research, binder modification with added material such as rubber or nanoparticles are highly recommended to improve strength and durability of asphalt porous. However, another method need to be proposed for reduction of particle size in fly ash into nanomaterial range.