Journal articles: 'Mechanical rack'

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Men, Zheng Xing, Ya Xin Ma, Tai We Yue, and Rui Lin Liu. "Analysis on the Free Forging Process of the Heavy Rack for Ship Lift." Applied Mechanics and Materials 865 (June 2017): 105–8. http://dx.doi.org/10.4028/www.scientific.net/amm.865.105.

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Heavy racks are the main load-bearing components and play more important position in great engineering equipments. Along with the requirement of the equipment efficiency promotion, the large-scale trend of rack is obvious. Among them, the rack for the Chinese Three Gorges ship lift total up to 5000mm. At present, the large rack mainly made by casting. Compared with the casting, the forging rack can greatly improve the mechanical properties and the service life. The aim of this work is feasibility analysis of free forging for large rack, as large T-shape section forging. Four possible forging schemes were simulated and compared by the finite element method, and the possible defects of all the schemes and their application scope were explored. Finally, it was proved that the free forging of heavy rack was realized by simple dies.

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Fulpagare, Yogesh, Yogendra Joshi, and Atul Bhargav. "Rack level transient CFD modeling of data center." International Journal of Numerical Methods for Heat & Fluid Flow 28, no. 2 (February 5, 2018): 381–94. http://dx.doi.org/10.1108/hff-10-2016-0426.

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Purpose The paper aims to capture the rack-level thermal dynamics in data center. It proposes the rack-level response experiments as well as transient Computational Fluid Dynamics (CFD) analysis to characterize the local thermal environment of the system. Design/methodology/approach A single sever simulator rack and its two neighboring racks with its cold and hot aisle containment have been modeled with known cold air supply temperature and flow rate for transient CFD analysis. The heat load was kept constant initially and varied case-to-case basis, which includes capturing the rack-level response with respect to changes in input. However, the response experiments on simulator rack were performed for 14 h by variation of server heat loads as step and ramp input. Findings The paper provides the detailed transient CFD analysis of data center racks. The local cold air flow rates and temperature at the vicinity of the racks showed significant effect due to changes in input. It was concluded that the rack-level dynamics impacts the thermal environment of data center and hence cannot be ignored. Research limitations/implications The high computing devices and faster internet demands have led to major thermal management concerns for data center operators. To tackle this issue, capturing the system thermal dynamics is imperative. However, the system-level CFD analysis is computationally expensive. Therefore, this paper deals with the rack-level transient CFD study using commercial tool STAR CCM+. Practical implications This paper includes the modeling of the servers as a porous media as well as the multigrid method to enhance the computational speed. The successful implementation of this approach validated through experiments. This would help to establish a base for research in any type of data center. Originality/value This paper provides the porous media approach to model servers and multigrid method to enhance the computational speed. At the same time, the thought of characterizing the local dynamics at the vicinity of data center racks is unique.

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Reddy, Dr Chanda V. "IOT Based Ambulatory Bag Mechanical Ventilator." International Journal for Research in Applied Science and Engineering Technology 9, no. 8 (August 31, 2021): 1435–39. http://dx.doi.org/10.22214/ijraset.2021.37526.

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Abstract: The IoT-based Ambu bag mechanical ventilator is a ventilator that automates the process of hand press mechanism using the rack and pinion mechanism. The circulatory motion of the rack is converted into linear motion which helps to press the Ambu bag. The proposed project works on three modes of operation that is child-adult and elder which is set wrt to the breaths per minute. There are two states of operation one normal state where the normal working is evidenced whereas the other operation mode is emergency where the buzzer is themed on in case of emergency. All the parameters are displayed on LCD and connected to the IoT cloud to communicate remotely in the end device Keywords: Ambulatory Bag, IoT network, Rack and Pinion mechanism, Manual resuscitator, mechanical ventilators

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Yang, Hsueh-Cheng, and P. Frank Pai. "Kinematic performance of a parabolic gear tooth with two parabolic coefficients." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 231, no. 23 (September 14, 2016): 4431–40. http://dx.doi.org/10.1177/0954406216668205.

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This paper presents design imaginary skew rack cutters having teeth of two parabolic coefficients to generate spur and helical gears. First, a mathematical model of the imaginary rack cutter having teeth of two parabolic coefficients is derived using geometric relations and coordinate transformation. After the relationship between the coordinate system of the imaginary rack cutter and that of the helical gear pair is set up, a family of imaginary rack cutter surfaces is obtained using the homogeneous coordinate transformation matrix to transfer the coordinate system of the rack cutters to that of the helical gear. Based on the gear theory, the equations of meshing between the rack cutter and the helical gear are determined. Substituting the equations of meshing into the family of imaginary rack cutter surfaces, a pinion and a gear are generated and their geometries are plotted using an in-house software package. Based on the assembly errors, tooth contact analysis is performed to determine the influences of kinematic assembly errors and the parabolic coefficients. Results show that maximum parabolic coefficient value of the imaginary skew rack cutter exists in order to avoid undercutting and it can be determined.

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Hou, Shun Li, Hai Yan Yang, and Xiong Bo Su. "Mechanical Property Analysis of the Frame of Papermachine Dry Section Based on Finite Element Method." Advanced Materials Research 524-527 (May 2012): 3896–99. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.3896.

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This essay analyses the mechanical behavior of the paper machine drying section rack by FEA method, obtaining transformation and stress distribution of the rack under static loading, so as to achieve the natural frequency and the corresponding strain, stress of the rack. This paper could provide theoretical foundation for design, fault diagnosis or reforming speed acceleration.

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Brown, Alan S. "Too Hot for Comfort." Mechanical Engineering 128, no. 12 (December 1, 2006): 32–34. http://dx.doi.org/10.1115/1.2006-dec-3.

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Electronics have grown much hotter over the past decade, making cooling a top priority in data centers. APC, better known for backup power supplies, supplies cold air from rack-size towers mounted along each row. It then monitors server temperatures, adjusting each individual air conditioner tower to achieve optimal cooling. Such localized cooling is efficient, such that users can boost server rack power to 18 kW—nearly nine times the average found by Uptime. IBM believes even the largest, most sophisticated data center managers need help with cooling. Like APC, it encloses its racks with a roof, but unlike APC it uses a cold rather than hot center aisle and exhausts the heated air into the data center. IBM also removes heat with a water-cooled heat exchanger attached to the back of a rack. In addition, IBM provides power management software that enables IT managers to adjust power and heat output. This ensures that power managers can power down based on workload, or move workload to environments that are not effectively using the power and cooling capacity that they have.

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Gusella, Federico, Maurizio Orlando, Andrea Vignoli, and Klaus Thiele. "Flexural Capacity of Steel Rack Connections Via The Component Method." Open Construction and Building Technology Journal 12, no. 1 (May 23, 2018): 90–100. http://dx.doi.org/10.2174/1874836801812010090.

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Background: In pallet rack structures, cold-formed steel (CFS) beams and columns are connected through dry joints, so beams can be easily disconnected according to changes of the rack geometric layout. Due to the great variety of connector types and member geometries, recent design codes recommend experimental tests on rack connections to assess their mechanical features. Nevertheless, tests only allow for the overall response of a joint to be evaluated, without providing information about the contribution of each component of the joint to its stiffness and strength. Objective: In this paper, a mechanical model is developed in order to provide useful information about the structural behaviour of rack beam-column connections. Methods: The proposed mechanical model is based on the application of the Component Method (CM) and it allows for the flexural resistance of steel rack connections to be analytically assessed. Analytical results are compared with experimental data from tests performed at the Structures and Materials Testing Laboratory of the Department of Civil and Environmental Engineering of Florence. Results: Results show a good agreement with experimental data, highlighting the accuracy of the proposed approach. The mechanical model allows for the weakest component of the joint and its failure mode to be evaluated, and it highlights the importance of an adequate welding between the beam-end section and the connector. Conclusion: The mechanical model provides fundamental information about the influence of structural details on the overall behavior of rack joints, it appears as a complementary method to expensive experimental tests and it can be used to improve the design of rack connections with the goal to increase their structural response.

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Blatnická, Mária, Milan Sága, and Miroslav Blatnický. "Design and strength analysis of mechanical rack system." MATEC Web of Conferences 254 (2019): 01017. http://dx.doi.org/10.1051/matecconf/201925401017.

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The paper deals with a construction design of the rack system which will be used for storage of metallurgical rod material in a manufacturing engineering company. To meet requirements for manual control of the pull-out mechanism it will be determined the force exerted by the worker on the hand crank required to pull in and pull out the racking system at the full load. In addition, stress analysis was conducted by means of finite element method.

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Antypas, Imad R., and Alexey G. Dyachenko. "Modeling, Studying and Manufacturing a Cultivator Rack from Composite Materials." Mordovia University Bulletin 28, no. 3 (September 20, 2018): 366–78. http://dx.doi.org/10.15507/0236-2910.028.201803.366-378.

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Introduction. The composite materials have not been widely used in the Russian economy (especially in agriculture) until recently. It is relevant to use them for manufacturing some parts of agricultural machinery, for example, racks of cultivator paws. These parts often break down because of stress concentration in the places where their thickness changes during the time of plowing. The stress can be decreased by using com- posite materials. Materials and Methods. This paper presents the study results on the use of composite materials for manufacturing of cultivator racks with the appropriate selection of the volume ratio of fibers in each of the layers of fabric and layers of binder. Results. Based on the results, the design safety factor was calculated to be equal to 2. It should be noted that the values of the mechanical characteristics of the material changed because of the presence of a porosity coefficient, which was 11.6 %, while the allowable value was 4%. Field tests have shown the durability of a new composite material, even under severe operating conditions, compared to a conventional rack made of alloy steel. Conclusions. Studying the mechanical behavior of the rack geometric model and modeling a material with high mechanical properties, which later was used for manufacturing a composite material, we could get the minimum safety factor of 4, with the maximum safety factor for workers – 15. The racks from composite material are economically feasible as less expensive than used steel racks.

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Yang, Hsueh-Cheng, and Wen-Jun Liang. "A helical gear with discrete ring-involute teeth." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 8 (December 15, 2019): 1554–68. http://dx.doi.org/10.1177/0954406219893392.

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This study produces a skewed-imaginary planar rack cutter with discrete conical teeth that is used to create a helical gear with discrete ring-involute teeth. A mathematical equation for the skewed-imaginary rack cutter with discrete conical teeth is firstly solved. The coordinate system for the rack cutter and gear pair is then established and a family of the rack-cutter surfaces is obtained using homogeneous coordinate transformation. The relative velocity method is used to produce the equation for meshing between the rack cutter and the gear pair. Substituting the equation of meshing into the family of the rack-cutter surfaces gives the mathematical models for the gear pair with discrete ring-involute teeth. The transmission error for the gear pair is calculated using the assembly error and a tooth contact analysis. A computer-aided design software package is used to establish solid model for the gear pair. A software interference function is used to simulate the contact condition for the gear pair for various assembly errors. Finite element analysis software is then used to determine the contact stress for the gear pair. The transmission error and the contact stress for the gear pair are insensitive to any horizontal misalignment in the assembly errors.

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Al-Talib, Ammar Abdulaziz, and See Kai Sheng. "A Rack and Pinion Driven Mechanical Footstep Power Genarator." Proceedings of International Conference on Artificial Life and Robotics 25 (January 13, 2020): 370–75. http://dx.doi.org/10.5954/icarob.2020.os8-1.

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Safronov, Eugene, and Andrey Nosko. "A Method to Determine Allowable Speed for a Unit Load in a Pallet Flow Rack." Acta Mechanica et Automatica 13, no. 2 (June 1, 2019): 80–85. http://dx.doi.org/10.2478/ama-2019-0011.

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Abstract Pallet flow rack are widely used in intralogistics to maximize warehouse capacity and to reduce the travel by fork-lifts. However, the use of pallet flow racks is associated with increased danger due to the use of gravity conveyors in their design. For this purpose, the gravity conveyors of pallet flow rack have a two safety elements – brake rollers and a stopping mechanism with pallet separator, which are working as a system. Brake rollers limit the speed of pallets, while the stopping mechanism allows exuding a pressure on the unloading pallet from the following behind it. A pallet should have such a speed, controlled by the brake rollers, so that it could be stopped by a stopping mechanism without damaging it. Based on the Cox impact theory, an original method for determining the allowable speed of a pallet in a pallet flow rack is proposed. The method ensures safe operation of the stopping mechanism with pallet separator and takes into account the mechanical properties and design parameters of the pallet separator stopper. A calculation example is provided for the most commonly used types of pallets – Euro pallet (1200 mm × 800 mm) and Industrial pallet (1200 mm × 1000 mm). The obtained results agree well with the pallet speed range of 0.2 to 0.3 m/s recommended by the manufacturers of pallet flow racks.

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Yang, Hsueh-Cheng, and Chih-Yao Sun. "Using a planar rack cutter with variable modulus to generate a spherical gear pair." Transactions of the Canadian Society for Mechanical Engineering 44, no. 1 (March 1, 2020): 108–20. http://dx.doi.org/10.1139/tcsme-2018-0265.

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In this study, an imaginary planar rack cutter with variable modulus and discrete conical teeth was used to generate a spherical gear pair with double degree of freedom. First, a geometric method was used to design the mathematical model of the imaginary planar rack cutter with variable modulus and discrete conical teeth. Next, the relationship of coordinate systems between the generating and generated surfaces was established. Then, the family of the imaginary planar rack cutter surfaces was obtained by homogeneous coordinate transformation matrix. Further, two equations of meshing between the generating and generated surfaces were determined by the two-parameter envelope theory. The mathematical model of spherical gear pair with variable modulus and discrete ring-involute teeth can be created by using the two equations of meshing and the family of the imaginary planar rack cutter surfaces. The mathematical models of the spherical gear pair with double degree of freedom and tooth contact analysis method were used to investigate the assembly errors of the gear pair in four cases.

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Dehyadegari, Amin, MirFaez Miri, and Zahra Etesami. "Dynamics of noncontact rack-and-pinion device subject to thermal noise: Multiharmonic motion of the rack." International Journal of Non-Linear Mechanics 89 (March 2017): 75–82. http://dx.doi.org/10.1016/j.ijnonlinmec.2016.11.009.

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Abadjieva, Emilia, Valentin Abadjiev, and Akihiro Naganawa. "Spatial Rack Drives Pitch Configurations: Essence and Content." Journal of Theoretical and Applied Mechanics 48, no. 1 (March 1, 2018): 3–22. http://dx.doi.org/10.2478/jtam-2018-0001.

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Abstract The practical realization of all types of mechanical motions converters is preceded by solving the task of their kinematic synthesis. In this way, the determination of the optimal values of the constant geometrical parameters of the chosen structure of the created mechanical system is achieved. The searched result is a guarantee of the preliminary defined kinematic characteristics of the synthesized transmission and in the first place, to guarantee the law of motions transformation. The kinematic synthesis of mechanical transmissions is based on adequate mathematical modelling of the process of motions transformation and on the object, realizing this transformation. Basic primitives of the mathematical models for synthesis upon a pitch contact point are geometric and kinematic pitch configurations. Their dimensions and mutual position in space are the input parameters for the processes of design and elaboration of the synthesized mechanical device. The study presented here is a brief review of the theory of pitch configurations. It is an independent scientific branch of the spatial gearing theory (theory of hyperboloid gears). On this basis, the essence and content of the corresponding primitives, applicable to the synthesis of spatial rack drives, are defined.

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Hribernik, Aleš. "Evaluation of Clogged Hydropower Plant Trash Rack Losses." Strojniški vestnik – Journal of Mechanical Engineering, Volume 66, Issue 2 (February 15, 2020): 142–52. http://dx.doi.org/10.5545/sv-jme.2019.6313.

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Lewis, G. M., R. A. Cooper, and M. D. T. Freeman. "The automated load testing of pallet rack connections." Strain 25, no. 2 (May 1989): 57–59. http://dx.doi.org/10.1111/j.1475-1305.1989.tb00691.x.

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Zhang, Ren Cai, Xiang Yu, Xing Ju Liu, Jin Hai Zhai, and Zhen Wu Ning. "Study on Mechanical Automation with Design of Rapid Milk Detector Based on Freezing Point." Advanced Materials Research 703 (June 2013): 282–86. http://dx.doi.org/10.4028/www.scientific.net/amr.703.282.

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An efficient automated milk detector based on freezing point depression is designed. This detector shares characters of high efficiency and good stability with accuracy and automation. Its main parts include temperature sensor of IC (Integrated Circuit), pinion-rack mechanism and crank-rocker mechanism and electronic control system. Monitoring in-situ change of milk freezing curve and developing efficiency of sampling can be available by means of pinion-rack mechanism and IC temperature sensor mechatronics design. As a result, adulterating status of milk can be discriminated in a rapid and accurate and automated way. The detector may be employed to detect liquid foods other than milk as well.

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Marimuthu, P., and G. Muthuveerappan. "Optimization of fillet stress to enhance the bending strength through non-standard high contact ratio spur gears." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 230, no. 7-8 (August 20, 2015): 1139–48. http://dx.doi.org/10.1177/0954406215602287.

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The present study aims to determine the improvement in the bending strength of the non-standard high contact ratio spur gears based on the balanced (optimum) fillet stress of the pinion and gear. The average number teeth in contact is more than two for high contact ratio gear drives. In the non-standard high contact ratio spur gears, the rack cutter tooth thickness factor is more than 0.5, whereas the standard rack cutter tooth thickness factor is 0.5. The maximum fillet stresses of the pinion and gear is not equal for non-standard high contact ratio spur gear drives when the gear ratio increases. In order to avoid the fatigue failure of the gear, the fillet stresses of the pinion and gear should be balanced. This balanced stress is predicted as the optimum fillet stress. Hence, the present study focuses to optimize the fillet stress with respect to the rack cutter tooth thickness factor of the pinion and gear through finite element analysis. Also, a parametric study is carried out to obtain the influence of some gear parameters, such as gear ratio, teeth number in the pinion, pressure angle, addendum height and corrected gear drives (S+, S− and So) on the optimum fillet stress with respect to the rack cutter tooth thickness factor of the pinion and gear.

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Druesne, F., and M. Afzali. "Electroplating simulation and design tool." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 217, no. 5 (May 1, 2003): 705–7. http://dx.doi.org/10.1243/095440503322011434.

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Electroplating process energy and material costs are very important considerations in product manufacturing. The most important plating criteria, however, are quality and plated uniformity of the deposited metals. Simulation tools can help to obtain better plating results. New plating simulation tools are now available that will run on PC/Windows computers and can point the way to optimizing many common electroplating processes. Software packages are available that are versatile and user friendly. These tools have been designed to optimize electroplating cells and racks. An accurate analysis is required to determine the distribution of deposited thickness, current densities and electrode potentials. A good plating simulation tool can help an engineering team find the most reliable rack configuration based on the geometrical description of the rack, the parts to be plated and from calculation of the electrochemical properties of the process being studied.

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Zhao, Wu, and Dan Huang. "Load Spectrum Test and Numerical Simulation on the Rolling Rack for Dynamic Design and Control." Advanced Materials Research 346 (September 2011): 405–11. http://dx.doi.org/10.4028/www.scientific.net/amr.346.405.

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The sustained rolling mill vibration on high-speed cold rolling mill or smooth mill could cause that periodicity sheet thickness difference or board light and dark stripes, or rolling processing interruption for the large vibration intensity. Dynamic load behavior of the rolling mill rack including the load magnitude and load property usually was the reason of the vibration, which caused the vibration modal with diversity and uncertainty. Three-dimensional solid modeling software and finite element analysis software had been used to realize computer simulation on deformation and stress field calculation of the rack rolling mill for completing rolling processing performance evaluation of the plate rolling mill. By strain gauges being layout to be half-bridge circuit in its suitable location to detect the one-direction strain on the rack, the loading capacity of rolling mill’s rack was studied for its dynamic characterization behavior. By extracting rolling force signal on actual measured and statistical analyzing calculations of experimental data on the plate rolling mill, rolling force load spectrum was obtained. Analysis model on rack was established in order to calculate and analyze mechanical and power parameters based on finite element method. It was used for improving dynamic design, also for analyzing mechanical and power parameters matching with increasing production and product variety under rolling schedule reinforcement. This study work provide theoretical foundation on ensuring stable operation of equipment, which was benefits on increasing production and product variety, even rolling processing potential scope.

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Zhang, Jing Dong, Xue Mei Qi, and Rui Tang. "Modal Analysis of Airborne Equipment Mounting Rack." Applied Mechanics and Materials 312 (February 2013): 282–86. http://dx.doi.org/10.4028/www.scientific.net/amm.312.282.

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Stability and safety performance of aircraft is determined by reliability of aviation airborne equipment, airborne equipment mounting rack work under severe mechanical vibration. To improve the system reliability, we established accurate parametric finite element model, obtained modal of frequency and vibration by analysis, confirmed correctness of this method by experiment, laid the foundation of its comprehensive dynamic analysis and structure optimization design for structure and working conditions of a electronic equipment mounting rack in this paper.

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Liu, Jia Zhen, Yan Hui Zhao, Lei Song, and Zhong Xia Xiang. "Study on the AZ31B Magnesium Alloy in the Application on High-Speed Trains." Advanced Materials Research 535-537 (June 2012): 875–79. http://dx.doi.org/10.4028/www.scientific.net/amr.535-537.875.

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6063 aluminum alloys are used as the luggage rack’s material on high-speed trains recently. The study on the AZ31B magnesium alloy is aimed to demonstrate the feasibility of the magnesium alloy’s application as the material of the luggage rack on high-speed trains. First, the mechanical properties of the AZ31B magnesium was obtained after a series of experimental tests on basic mechanical properties of the AZ31B magnesium alloy. The results show that the strength of the magnesium alloy is 1.25 times of the 6063 aluminum alloy and the impact toughness of the AZ31B magnesium alloy is twice as much as the 6063 aluminum alloy. Second, the stress distribution and the maximum value of the equivalent stress in given loading conditions was obtained by finite element strength analysis on the structure of the aluminum alloy luggage rack on high-speed trains. And the FE analysis results indicate that if the AZ31B magnesium alloy is used as the material of the luggage rack instead of the 6063 aluminum alloy, it will have a weight loss of the luggage rack for approximately 33%. In addition, the application of AZ31B magnesium alloy has more advantages in energy-saving, environmental protection and safety control.

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Gusella, Federico, Sanjay Raja Arwade, Maurizio Orlando, and Kara D. Peterman. "Influence of mechanical and geometric uncertainty on rack connection structural response." Journal of Constructional Steel Research 153 (February 2019): 343–55. http://dx.doi.org/10.1016/j.jcsr.2018.10.021.

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Hui, Jianghai, Min Gao, and Xinpeng Li. "Design and optimization of spin micro-generator's rotating rack used in trajectory correction fuze under high-impact loadings." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 13 (December 22, 2018): 4421–38. http://dx.doi.org/10.1177/0954406218819034.

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Buffer structure is a traditional measure to improve the ammunition's performance of withstanding impact loadings during launch process. On that basis, this paper proposes a parametric optimization for the gasket, which is served as buffer structure in spin microgenerator's rotating rack used in trajectory correction fuze to effectively reduce the stress of bearings used in the rack. It is a finite element dynamic simulation based on rack-projectile-barrel coupling to acquire variation of the bearings' stress. A rack-projectile-barrel coupling model is built and the simulation pre-process is described. At first, the parametric analysis for the gasket is conducted. The effect of the gasket's axial thickness and elastic modulus on the bearings' stress is studied, and the results show that singly changing one of the two gasket's parameters cannot effectively reduce the two-ball bearings' stress. Then, based on the two gasket's parameters, the design of experiment method is applied with 25 sample points established. A kind of approximation, response surface model is created and its fitting accuracy is verified. Single-objective and multi-objective optimization are conducted based on the response surface model, respectively. And the multi-objective optimization for the gasket can successfully reduce the two bearings' stress to the value below the bearing material's yield strength. In addition, to check the optimization's effectiveness, an experiment is carried out and the results indicate that the gasket whose axial thickness and elastic modulus have been optimized can effectively improve the rotating rack's performance of withstanding impact loadings.

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Wang, Youmin, Xiangli Li, and He Sui. "Numerical Investigation and Mold Optimization of the Automobile Coat Rack Compression Molding." Advances in Materials Science and Engineering 2021 (April 30, 2021): 1–19. http://dx.doi.org/10.1155/2021/6665753.

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In order to have more accurate control over the compression molding of automobile coat rack, improve the quality of molding products, and achieve the goal of lightweight design, a novel mechanical model for the main two-layer composite structure of the coat rack is proposed. In this regard, the main factors affecting the mechanical properties of the composite structure are obtained. The hot air convection is selected for the sheet preheating. During the experiment, the hot air temperature, preheating time, molding pressure, and pressing holding time are set to 250°C, 110 s, 13 MPa, and 80 s, respectively. Moreover, the error compensation method is applied to compensate for the shrinkage of the product during solidification and cooling. The LS-DYNA finite element software is used to simulate the molding process of the main body of the coat rack, and the node force information with large deformation is obtained accordingly. The load mapping is used as the boundary condition of mold topology optimization, and the compression molding of the main body of the coat rack is optimized. A lightweight design process and method for the compression molding of automotive interior parts and a mathematical model for the optimization of the solid isotropic material penalty (SIMP) (power law) material interpolation of the concave and convex molds are established. Based on the variable density method, OptiStruct is used for the lightweight design of the convex and concave molds of the main body of the coat rack, which reduces the mold weight by 15.6% and meets the requirements of production quality and lightweight.

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Cheng, Bo, and Zhenyu Wu. "Investigation of Shear Stiffness of Spine Bracing Systems in Selective Pallet Racks." Open Construction and Building Technology Journal 9, no. 1 (May 29, 2015): 1–6. http://dx.doi.org/10.2174/1874836801509010001.

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This paper presents a general analysis on the shear stiffness of spine bracing systems of selective storage racks in the down-aisle direction. Unlike the architectural steel structure, the bearing capacity of bracing connection in the spine bracing systems of steel rack structure is weaker than that of bracing members. Firstly, destructive tests of spine bracing connection in single entry racks have been conducted. In the tests, a portion of column web around bolt holes is damaged due to the pull force of connecting bolts. Based on the experimental results, the finite element shell model of tested bracing connection is developed, and the emulation method is also used to analyze the deformation behavior of spine bracing connections in double entry racks. The calculating results indicate that, with better mechanical behavior and less local deformation, the tensile stiffness of bracing connection in double entry racks is much larger than that of bracing connection in single entry racks. From the trial calculation, the simplified models using elastic plastic beam elements are proposed. These simplified models can be adopted in the overall deformation analysis of selective pallet racks subjected to horizontal loading. Through the comparative analysis of single entry racks and double entry racks which have four bays and eight floors, the lateral deformation of double entry racks is considerably less than that of single entry racks, showing the large different effect of spine bracing systems on two rack lateral behavior.

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Svahn, Mattias. "A parametric analysis of the surface roughness of teeth shaped by a pinion shaper cutter and guidelines for choosing process parameters." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 21-22 (April 22, 2019): 7368–77. http://dx.doi.org/10.1177/0954406219843951.

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A parametric mathematical model is presented, by which it is possible to determine the machined gear tooth surface topography cut by a pinion shaper cutter. Arbitrary internal or external helical gears designs can be considered, the gear and the shaper cutter must only share a basic rack design. The basic rack has here an elliptical fillet, as it allows fewer tool tooth numbers without the risk of undercut. The machined tooth surface is presented in three dimensions and by surface roughness parameters [Formula: see text], and [Formula: see text]. A novel method to choose cutting parameters and tool design is also presented.

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Wang, Xu, and Simon Watkins. "Reduction of roof rack noise and vibration." International Journal of Vehicle Noise and Vibration 6, no. 2/3/4 (2010): 105. http://dx.doi.org/10.1504/ijvnv.2010.036680.

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Hefeng, Bai, Michael Savage, and Raymond James Knorr. "Computer modeling of rack-generated spur gears." Mechanism and Machine Theory 20, no. 4 (1985): 351–60. http://dx.doi.org/10.1016/0094-114x(85)90040-0.

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Brunella, Sandro, Willi H. Hager, and Hans-Erwin Minor. "Hydraulics of Bottom Rack Intake." Journal of Hydraulic Engineering 129, no. 1 (January 2003): 2–10. http://dx.doi.org/10.1061/(asce)0733-9429(2003)129:1(2).

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32

He, Jia Ning, Wei Zhang, Hai Bin Zhang, Wu Xing Ma, Si Chen, Qiang Li, and Yong Gao. "Study on Minimum Teeth without Undercutting of Standard Involute Gears." Advanced Materials Research 199-200 (February 2011): 329–36. http://dx.doi.org/10.4028/www.scientific.net/amr.199-200.329.

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In textbooks of mechanical engineering, rack has been mistakenly regarded as rack cutter so that minimum teeth without undercutting have been deduced, which has made people misunderstand undercut phenomenon more than 65 years. Theoretical research and computer simulation about undercut phenomenon are presented in this paper. Firstly, the theoretical analysis and calculation on minimum teeth without undercutting have been carried out, the rack cutter is used to infer minimum teeth without undercutting of standard involute gears, and correct minimum teeth without undercutting are get; And then computer simulation is applied to verify validity results of theoretical calculations, which not only corrects the long-standing mistakes about the traditional undercut phenomenon, but also provides the correct theoretical guidance for gears’ manufacturing.

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33

Hao, Jin Ying, and Lin Wu. "Modeling and Simulation of the Crawler Passing Institutions of a New Type of Entertainment Machine with Mechanical Engineering Materials." Advanced Materials Research 648 (January 2013): 153–57. http://dx.doi.org/10.4028/www.scientific.net/amr.648.153.

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The research is a passing mechanism of one new entertainment machine .It can deliver the ball to the destination by the chain wheel which can drive a track in a large angle of elevation .Through the UG6.0, one model basis on the mechanical engineering materials is accurate. It can pass the assembled passing crawlers and racks into ANSYS, at the same time it can also have a static analysis on the track firstly after the repair. Due to the mechanical engineering materials we have three operating modes that can find out the most dangerous place. With the support of the crawler calculation results, it can compute the stress condition of a rack in travel to demonstrate the feasibility of this passing scheme.

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34

Gao, Yan’e, Bingkui Chen, and Dong Liang. "Mathematical models of hobs for conjugate-curve gears having three contact points." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 229, no. 13 (November 21, 2014): 2402–11. http://dx.doi.org/10.1177/0954406214558674.

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Conjugate-curve gears are the gears which are point contact and the locus curves of the contact points are conjugate curves. The contact pattern of the conjugate-curve gear tooth surfaces are convex to concave, which reduces the contact stress of the tooth surfaces due to the small value of the relative curvature radius at the contact point. The tubular tooth surfaces of the conjugate-curve gears have one pair of conjugate curves. To decrease the running-in time and increase the load capacity, the conjugate-curve gears having three pairs of conjugate curves are designed. The contact stress of the tooth surfaces having three contact points is much smaller than that of the tubular tooth surfaces in the computer contact analysis. For the further study of the performance of the conjugate-curves gears having three contact points, hobs are considered to manufacture the gears. Two mismatched rack cutters having three contact points are applied for the design of hobs. The working edge in the normal section profile of the rack cutter for the hob generating the pinion is a circular arc and the working edges in the normal section of the rack cutter for the hob generating the gear are two parabolic curves that are tangent to the convex circular arc. By applying the designed rack cutter profiles, the principle of coordinate transformation, the differential geometry theory, and the theory of gearing, mathematical models of the hobs are established. To verify the proposed tooth profile and the hobs, the experimental cutting trials and the load capacity test are carried out. The final accuracy of the gear satisfies the design requirements. The results demonstrate the feasible of the proposed design method.

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35

Madhamshetty, Karthik, and James Manimala. "Low-Rate Characterization of a Mechanical Inerter." Machines 6, no. 3 (July 18, 2018): 32. http://dx.doi.org/10.3390/machines6030032.

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In this study, improved analytical models, numerical parametric explorations, and experimental characterization are presented for a mechanical inerter to bring out dependencies for dynamic mass amplification under low rates (<5 Hz) of excitation. Two common realizations of the inerter—the ball-screw and the rack-and-pinion versions—are considered. Theoretical models incorporating component inertias and sizing were developed for both versions. The dependence of the specific inertance on key design parameters is explored through simulations. Based on these simulations, a prototype rack-and-pinion inerter delivering a specific inertance above 90 was designed, fabricated, and tested under low-rate displacement and acceleration-controlled excitations. The measured specific inertance was found to display an exponential decline with an increase in excitation frequency for both cases. Deviations from predictions are attributable to the frequency dependence of internal stiffness and damping in the fabricated prototype. Using a phase-matching procedure for a representative lumped model, the internal stiffness and damping in the prototype were estimated. Examination of the phase spectra reveals an influence of the excitation frequency on the internal stiffness, damping, and consequently specific inertance. Further, based on the results of this study, design perspectives for such mechanical inerters, which are seeing increasing use in several low-frequency applications, are also presented. It is envisioned that this approach can be utilized to subsume the specific nonlinear characteristics of individual inerters into a simple yet unsimplistic model that can be used to more efficiently and accurately predict the behavior of multi-element, inerter-based systems that employ them.

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36

Bilal, Ahmed, and S. S. Shah. "CAD Modeling of Store Carrying Rack-9 / Store Carrying Rack-9A, Their Aerodynamic Analysis and Validation through Wind Tunnel Test." Journal of Applied Fluid Mechanics 9, no. 3 (May 1, 2016): 1237–46. http://dx.doi.org/10.18869/acadpub.jafm.68.228.22971.

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37

Yan, Lu, Guohua Cao, Naige Wang, and Weihong Peng. "Schematic Diagrams Design of Displacement Suppression Mechanism with One Degree-of-Freedom in a Rope-Guided Hoisting System." Symmetry 12, no. 3 (March 18, 2020): 474. http://dx.doi.org/10.3390/sym12030474.

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Since it is difficult for lateral stiffness of rope-guided rails to meet industry criteria in deep construction shaft, schematic diagrams of displacement suppression mechanisms (DSMs) are designed with a systematic approach demonstrated to reduce the lateral displacement of rope-guided rails in this paper. DSMs are simplified as planar four-bar and six-bar topological graphs based on topological theory. Each corresponding mechanical chain of these four-bar and six-bar mechanisms is divided into a rack, mechanical parts, prismatic, and revolute joints. An extended adjacency matrix is defined to represent the rack position, specific types of kinematic joints, and adjacency relationships between kinematic parts. Then, a symmetric vertex identification method is proposed with regard to planar 1-DOF (one degree of freedom) four-bar and six-bar topological graphs to get the sequences of prismatic joints for kinematic chains of DSMs. Finally, the alternative schematic diagrams of DSMs are obtained. The results show four-bar mechanisms with simple structure; few kinematical parts but less resident force are suitable for a mine shaft with small space and small swing. Six-bar mechanisms with two prismatic joints and three mechanical rack degree are applicable for wide shaft space in deep shaft, due to their stable structure and double resistant force. This development is helpful for DSM dimension synthesis design in future.

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38

Spitas, C., and V. Spitas. "Generating standard 20° involute pinions with increased fillet strength by using 25° rack cutters with non-standard module." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 220, no. 8 (August 1, 2006): 1297–304. http://dx.doi.org/10.1243/09544062jmes350ft.

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According to all prevailing standards for gear design, a strict guideline is that the individual gears of a gear pair must be of the same module and pressure angle in order to mesh properly and the compatibility of the remaining geometrical parameters is determined under this assumption. However, in this article, the fundamental meshing principles of a generating rack and pinion are reinterpreted, and a more insightful form of the compatibility equations for involute gears is presented. In this context, stronger tooth forms with thicker root fillets can be produced using 25° rack cutters and still be able to mesh with standard 20° involute gears indiscriminately. The increased strength of pinions of the proposed design versus their standard counterparts is verified with finite element analysis.

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39

Nagy, Andor, and István Lakatos. "Examining the movement differences in the behavior of normal and rack railway vehicle." International Journal of Engineering and Management Sciences 4, no. 1 (March 3, 2019): 96–103. http://dx.doi.org/10.21791/ijems.2019.1.13.

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The rack railway is a special type of railroad. There weren”t much built worldwide, and their number is decreasing. Now, in Budapest, there is a possibility to create an interoperable vehicle, based upon the experience gained from the previously operated line, and all the research regarding its unique characteristics. One from the many important sector of its operation, is the rail/rack/vehicle system. Its mechanical model is far more complex than a traditional railroad vehicle. We will demonstrate its behaviorial differences from a traditional railroad vehicle.

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40

Yang, Xiaofeng, Yongchao Xue, and Jiaheng Zhou. "Stress Distribution and Fluctuation Cycle on the Rack Face of the Rock Cutting Tool." Shock and Vibration 2019 (December 9, 2019): 1–13. http://dx.doi.org/10.1155/2019/6830519.

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The distribution of the stress field on the rack face has significant impacts on the performance and service life of the rock cutting tool. A dynamic simulation model of the stress on the rock cutting tool is established by finite element code Abaqus, and the distribution of local stress on the rack face and its impact factors are studied. It is concluded that the local stress on the rack face of the rock cutting tool shows obvious periodical fluctuation characteristics, and the fluctuation cycle of each point on the tool remains unchanged under the same cutting conditions. The stress fluctuation cycle period decreases with the increase of cutting speed inversely. The cutting depth and the back angle of the cutting tool have no obvious impact on the stress fluctuation period. However, the cutting depth and the back angle have obvious impacts on the average stress distributions of each point on the rack face of the tool. That is, the increase of back angle and cutting depth could cause the maximum stress point of the rack face to move upward to the tool tip.

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41

Gusella, Federico, Maurizio Orlando, and Klaus Thiele. "Evaluation of rack connection mechanical properties by means of the Component Method." Journal of Constructional Steel Research 149 (October 2018): 207–24. http://dx.doi.org/10.1016/j.jcsr.2018.07.021.

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42

Iacomi, Paul, Ji Sun Lee, Louis Vanduyfhuys, Kyung Ho Cho, Pierre Fertey, Jelle Wieme, Dominique Granier, et al. "Crystals springing into action: metal–organic framework CUK-1 as a pressure-driven molecular spring." Chemical Science 12, no. 15 (2021): 5682–87. http://dx.doi.org/10.1039/d1sc00205h.

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Mercury porosimetry and in situ high pressure single crystal X-ray diffraction revealed the wine-rack CUK-1 MOF as a unique crystalline material capable of a fully reversible mechanical pressure-triggered structural contraction.

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43

SHIMAMUNE, Tsutomu, Masaaki MOCHIDA, Akio HASEGAWA, and Kohji ONO. "Grinding mechanism of helical gear with rack-tooth worm whell." Journal of the Japan Society for Precision Engineering 55, no. 6 (1989): 1029–34. http://dx.doi.org/10.2493/jjspe.55.1029.

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44

Kwon, Soon-man, and Da In Cha. "Strength Design of Rack and Pinion for an Articulated Linklift." Transactions of the Korean Society of Mechanical Engineers - A 43, no. 8 (August 31, 2019): 535–42. http://dx.doi.org/10.3795/ksme-a.2019.43.8.535.

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45

Yang, S.-C. "Meshing analysis of a gear with a ring-involute gear." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 217, no. 12 (December 1, 2003): 1287–99. http://dx.doi.org/10.1243/095440603322769938.

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The surface of a gear with ring-involute teeth generated by a rack cutter with ring-involute teeth is a new type of gear. This paper describes a method developed from gear theory for deriving a pinion and a gear with ring-involute teeth. A gear with ring-involute teeth is regarded as an envelope to the family of rack cutter surfaces when the pinion and gear rotate for a cycle. Using a developed mathematical model, the investigation on the undercutting analysis of the proposed gear is studied. Here the kinematic errors are investigated according to the obtained geometric modelling of the designed gear meshing when assembly errors were present. Stress analysis for the proposed gear was performed. Finally, a numerical example is presented to demonstrate the geometric model of a gear with ring-involute teeth and a gear ratio of 3:2.

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46

Abt, Steven R., Thomas E. Brisbane, David M. Frick, and Charles A. McKnight. "Trash Rack Blockage in Supercritical Flow." Journal of Hydraulic Engineering 118, no. 12 (December 1992): 1692–96. http://dx.doi.org/10.1061/(asce)0733-9429(1992)118:12(1692).

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47

Zheng, Zhanpeng, Chengjun Wu, Hengliang Wu, Jianyong Wang, and Xiaofei Lei. "Vibration isolation performance of nonobstructive particle damping in a machine rack." Journal of Vibration and Control 25, no. 5 (November 28, 2018): 1122–30. http://dx.doi.org/10.1177/1077546318814039.

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Nonobstructive particle damping (NOPD) is a novel passive control technology with strong nonlinear-damping. Many scholars put effort into the research on the internal mechanism of NOPD. In contrast, the application of NOPD to engineering has not received much research effort. A theoretical model based on the principle of gas–solid flows, which is employed to evaluate damping effect of NOPD and to predict dynamic response of a machine rack by a co-simulation approach, is established in this paper. In view of the difference between damping effect acting on the lateral and bottom of NOPD holes directly, total damping force is divided into lateral damping force and bottom damping force according to the Janssen theory of stress changed direction. Moreover, NOPD technology is applied to a machine rack for discussing its vibration isolation performance. The results indicate that NOPD technology can suppress the intense vibration, especially between 4000 Hz and 8000 Hz. It is noted that the theoretical model of NOPD can accurately predict the dynamic response of the machine rack with NOPD. The 1/3 Octave vibration energy spectrum indicates that NOPD technics can dissipate the vibration energy of the machine rack at full frequency, especially in 31.5 Hz, and attenuation up to 39.75 dB.

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48

Pau, Massimiliano, Bruno Leban, Antonio Baldi, and Francesco Ginesu. "Experimental contact pattern analysis for a gear-rack system." Meccanica 47, no. 1 (January 12, 2011): 51–61. http://dx.doi.org/10.1007/s11012-010-9415-8.

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49

Sim, K. S., and E. F. Ng. "Mechanical Design of Mini Automated Storage and Retrieval Warehouse System for Electronic Components." Applied Mechanics and Materials 575 (June 2014): 753–56. http://dx.doi.org/10.4028/www.scientific.net/amm.575.753.

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Automated storage and retrieval warehouse systems (ASRS) have been implemented in industrial for few decades. This kind of combination of project has become common in current industry field. Refer to Pa. Pittsburgh, the enhancement of ASRS has helped to improve optimal stock capacity in limited space and minimize process flow time. The purpose of this project is to design a hardware prototype that can fulfill the concept of ASRS and can be implemented at electronic components store that requires store management. This is to improve the process in stock checking and also store or retrieve item. Furthermore, there have several major parts that can be considered to use this hardware such as method of store and retrieve, storage structure, movement of the machine and machine travelling system. The timing belt system is implemented on this hardware for performing linear X-Y-Z motions. Besides, the concept of pallets supported rack had been implemented in storage structure design. Last but not least, the concept of an automated guided machine travels to the desired location on rack is selected as a store and retrieve method for this hardware.

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50

Yang, Chun Mei, Jing Li, Yan Ma, and Jing Ma. "Car's Internal Shield CNC Machining Technology and Analysis of Machine Tool Rack Mechanical." Key Engineering Materials 522 (August 2012): 206–9. http://dx.doi.org/10.4028/www.scientific.net/kem.522.206.

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We make a design of the block diagram of the guard fastening holes processing in this paper. It introduces the car doors composition and functional requirements, uses workbench to analysis the rack to determine its legitimacy. This design not only greatly improved the production efficiency of the car guard fastening hole machining, but also improve design standards and safety of the machine by model simulation analysis.

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Journal articles on the topic 'Mechanical rack'

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