Journal articles: 'Cylindricity Tolerance'

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Chahbouni, Mouhssine, Said Boutahari, and Driss Amegouz. "Influence of form deviations on the tolerance analysis." International Journal of Engineering & Technology 3, no. 3 (July 13, 2014): 343. http://dx.doi.org/10.14419/ijet.v3i3.2969.

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The objective of this paper is to present the influence of form deviations on the tolerance analysis of an assembly. For this we will study initially the tolerance analysis using the deviations and clearances domains method, a second time we will integrate the influence of form tolerances on the allowable deviation domain. To illustrate this analysis we used a classical assembly with position and form tolerances (coaxiality and cylindricity). Finally a comparative study between the two cases was illustrated. Keywords:Tolerance Analysis, CAD/CAM, Assembly Systems, Engineering Drawings.

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Weihua, Ni, and Yao Zhenqiang. "Integrating cylindricity error into tolerance analysis of precision rotary assemblies using Jacobian–Torsor model." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 227, no. 11 (February 1, 2013): 2517–30. http://dx.doi.org/10.1177/0954406213475553.

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In this study, the cylindricity error was integrated into the tolerance analysis of precision rotary assemblies using Jacobian–Torsor model. The contact method was developed to rapidly determine the actual fitting clearance through the virtual assembling of the mating cylindrical parts using Monte Carlo simulation. By modifying the expressions of small displacement torsors of the cylinder pairs, the actual fitting clearance between the bore and the shaft was taken into account, which overcame the shortage of Jacobian–Torsor model that the form error cannot be processed. The effects of the cylindricity error and the number of lobes on the actual fitting clearance and the functional requirements were analyzed in detail. The results show that the cylindricity error has significant influence on the actual fitting clearance and the final functional requirements, and it should not be ignored in the tolerance analysis for precision rotary assemblies.

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Weihua, Ni, and Yao Zhenqiang. "Cylindricity modeling and tolerance analysis for cylindrical components." International Journal of Advanced Manufacturing Technology 64, no. 5-8 (April 5, 2012): 867–74. http://dx.doi.org/10.1007/s00170-012-4078-3.

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Abbassi, Amira, Ali Trabelsi, Sofien Akrichi, and Noureddine Ben Yahia. "Assessment of cylindricity and roughness tolerances of holes drilled in marble using multiple regression and artificial intelligence." Advances in Mechanical Engineering 13, no. 8 (August 2021): 168781402110406. http://dx.doi.org/10.1177/16878140211040647.

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The Calacatta-Carrara marble is widely used due to its excellent physico-chemical characteristics and attractive aspect. However, the sensitivity of this materiel, when performing delicate manufacturing operations, presents for the engineers a hard challenge to overcome. This issue is mainly encountered with complex shapes of parts, for which it is difficult to preserve surface integrity and avoid geometric defects. The paper aims at finding out optimal drilling parameters of cutting in the Calacatta-Carrara white marble material, in order to minimize the holes cylindricity (HC) and surface roughness (HR) using six controlled operating factors, namely, the rotation speed ( N), the feed speed ( F), the drill bit diameter (BD), the drill bit height (BH), the number of pecking cycles ( P), and the drilling depth (DD). The experimental design uses a [Formula: see text] fractional factorial plan that is replicated once for cost consideration. The optimization process, that is, minimum cylindricity and roughness tolerances, is carried out using the Gray Relational Analysis (GRA) technique. Numerical modeling of machining parameters is performed using Multi-Layer Perceptron Artificial Neural Network (MLP ANN) and Multiple Regression Model (MR) to predict surface quality. For the sake of completeness these two models were compared in terms of fitness and predictability. The models were assessed statistically using the correlation coefficient. Results showed that either solution predicts a roughness tolerance which is in good agreement with the test data (both R-sq.(adj.) and R-sq.(pred.) >94%). However, the holes cylindricity tolerance response was shown to be superior with MLP-ANN model (R-sq.(adj.) 50.64% and R-sq.(pred.) 48.67%). The GRA analysis shows that minimum cylindricity and roughness are met when N and F are set high, BD and BH low, P high and DD low.

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Singaravel, B., Chimmalagi Marulaswami, and Thangiah Selvaraj. "Analysis of the Effect of Process Parameters for Circularity and Cylindricity Errors in Turning Process." Applied Mechanics and Materials 852 (September 2016): 255–59. http://dx.doi.org/10.4028/www.scientific.net/amm.852.255.

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Turning is one of the fundamental machining operations and its process parameters leads to better machining performance. The economic benefit of turning operation is providing components with appropriate dimensional accuracy. In this work, the effects of process parameters on dimensional accuracy (circularity and cylindricity) parameters are analyzed in turning of EN25 steel. The process parameters considered are cutting speed, feed rate and depth of cut in order to minimize circularity and cylindricity. The result revealed that the minimum dimensional accuracy error values such as circularity and cylindricity are obtained in the combination of higher value of cutting speed and lower value of feed rate and depth of cut. This analysis is used to meet the machined work piece within the tolerance limit and improve the quality criteria.

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Ariyanto, Ariyanto, and Husman Husman. "Pengukuran Kesilindrisan Hasil Proses Pemotongan Mesin Bubut Untuk Mengetahui Kemampuan Mesin Menghasilkan Suatu Produk." Manutech : Jurnal Teknologi Manufaktur 10, no. 02 (May 17, 2019): 9–13. http://dx.doi.org/10.33504/manutech.v10i02.61.

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The ability of machine tools to produce a product of good quality is needed by the industrial industry that exists today. Industrial industries that use machine tools are not only industries that produce products in the form of a tool or machine, machine tools are also widely used by industries or institutions that serve machine repair and providers of skills training. The quality of the machine measured using the geometry of the workpiece resulting from the machining process can be in the form of roundness, cylindrecity, tapers and other geometric shapes. The use of machine tools that continue for several years can result in a decrease in the ability of the machine to produce a product. The use of a long horizontal doall lt13 lathe will produce a form of workpiece cylindricity that is not the same as the condition of the the new machine tools, therefore testing activities are carried out by cutting the machine and seeing what the cylindrical value of the specimen is capable of achieving . From the results of the testing that has been carried out on a horizontal lathe as many as eight units, the values of cylindrical difference are different for each machine. The highest value of cylindricity is produced by lathes with machine number 8 and the smallest cylindrical value produced by lathes with machine number 3. The greatest tolerance is achieved in the quality of IT (international tolerance) 11 tolerance and the lowest is achieved in IT tolerance quality 10.

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Endrias, Dawit H., and Hsi-Yung Feng. "Minimum-Zone Form Tolerance Evaluation Using Rigid-Body Coordinate Transformation." Journal of Computing and Information Science in Engineering 3, no. 1 (March 1, 2003): 31–38. http://dx.doi.org/10.1115/1.1565075.

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This paper presents an optimization approach for the accurate evaluation of minimum-zone form tolerances from discrete coordinate measurement data. The approach minimizes the minimum-deviation objective function defined as the difference between the maximum and minimum distances of the measured coordinate data from the reference feature. The objective function is formulated as a function of rigid-body coordinate transformation parameters and involves fewer independent parameters than the existing tolerance evaluation algorithms. As a result, improved convergence efficiency and numerical stability are achieved. A standard direct search algorithm, the downhill simplex search algorithm, is employed to minimize the objective function. The least-squares estimates are employed as good initial conditions to facilitate convergence to the global solutions. A new method, named as the Median Technique, is implemented to well center the circularity measured data and well align the cylindricity measured data in order to provide valid least-squares estimates based on the Limacon approximation. Results from simulation and comparative studies have shown that the proposed method evaluates minimum-zone form tolerances with reliable accuracy.

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Zheng, Hong. "Non-Contact Online Detection of Concentricity Error." Applied Mechanics and Materials 733 (February 2015): 611–14. http://dx.doi.org/10.4028/www.scientific.net/amm.733.611.

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This paper researches on the non-contact online detection of concentricity error, which mainly focus on the structural principle of the measurement system and the concentricity error evaluation methods. The paper using the method of projection, converting the three-dimensional model to a two-dimensional model and evaluating coaxially error. And it is validated by the simulation of MATLAB. In theory, the proposed measurement system can measure geometric tolerance, including coaxially error, cylindricity error, circularity error, etc.

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Chen, Qianyong, Jinghua Xu, and Shuyou Zhang. "Cylindricity and flatness optimization for mechanical parts in additive manufacturing based on tolerance adaptive slicing." International Journal of Advanced Manufacturing Technology 115, no. 11-12 (June 11, 2021): 3839–57. http://dx.doi.org/10.1007/s00170-021-07271-4.

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Tóth, František, Juraj Rusnák, Milan Kadnár, and Pavol Čavojský. "Effect of Selected Ecological Lubricants on the Wear of Defined Sliding Bearing." Acta Technologica Agriculturae 17, no. 1 (March 1, 2014): 13–16. http://dx.doi.org/10.2478/ata-2014-0003.

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Abstract The presented contribution deals with the comparison of selected ecological oils of the same viscosity class in terms of wear of the sliding bearing B 60 M4 as part of the matched sliding pair lubricated by ecological lubricant. The wear of the sliding bearing is monitored using the parameters; the change of geometric tolerance cylindricity having the most indicative capability about the size and location of wear. The second parameter is weight loss, and the third parameter is the change of surface roughness at the contact point of friction elements. Results are statistically processed and presented in the form of graphs and tables.

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Liu, Ping, and Hui Yi Miao. "Research on a Computerized Form and Position Error Measurement Instrument." Applied Mechanics and Materials 201-202 (October 2012): 151–56. http://dx.doi.org/10.4028/www.scientific.net/amm.201-202.151.

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A model machine of multifunctional form and position measurement instrument controlled by a personal computer has been successfully developed. The instrument is designed in rotary table type with a high precision air bearing and the radial rotation error of the rotary table is 0.08 μm. A high precision vertical sliding carriage supported by an air bearing is used to the instrument, the straight motion error of the carriage is 0.3 μm/200 mm and the parallelism error of the motion of the carriage relative to the rotation axis of the rotary table is 0.4 μm/200 mm. The mathematical models have been established for assessing planar and spatial straightness, flatness, roundness, cylindricity, and coaxality errors. By radial deviation measurement, the instrument can accurately measure form and position errors of such workpieces as shafts, round plates and sleeves of medium or small dimensions with the tolerance grades mostly used in industry.

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Amini, Saeid, Mohammad Baraheni, and Alireza Mardiha. "Parametric investigation of rotary ultrasonic drilling of carbon fiber reinforced plastics." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 232, no. 5 (August 23, 2017): 540–54. http://dx.doi.org/10.1177/0954408917727199.

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Carbon fiber reinforced plastics are used in various industrial applications for their excellent properties. Rotary ultrasonic drilling is the new machining process used to drill holes on fiber-reinforced plastics and has been attracting increased attention in recent years. Dimensional tolerances are very important in machining of carbon fiber reinforced plastics. Additionally, diamond core drills are simultaneously drilling and grinding fiber reinforced plastics. This paper aims to investigate thrust force and dimensional tolerances including roundness and cylindricity in rotary ultrasonic drilling of carbon fiber reinforced plastics using diamond core drill. To this end, a proper ultrasonic system for a core drill in ABAQUS is designed and fabricated. Thrust force in rotary ultrasonic drilling when compared to conventional drilling reduced by up to 30%. Besides, roundness and cylindricity decreased by up to 80% and 72%, respectively. Afterwards, analysis of variance demonstrated that vibration is more influential than other machining parameters in order to improve the hole accuracy. That is, obtained exponential regression models predict roundness and cylindricity through machining parameters with high accuracy. Feed rate of 30 mm/min and spindle speed of 1400 r/min by exerting vibration on the tool is considered to be the optimized condition.

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Aamir, Muhammad, Majid Tolouei-Rad, Khaled Giasin, Ana Vafadar, Ugur Koklu, and William Keeble. "Evaluation of the Surface Defects and Dimensional Tolerances in Multi-Hole Drilling of AA5083, AA6061, and AA2024." Applied Sciences 11, no. 9 (May 10, 2021): 4285. http://dx.doi.org/10.3390/app11094285.

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Drilling is one of the most performed machining operations for riveting and assembly operations in many industrial sectors. The accuracy of the drilled holes and their surface finish play a vital role in the longevity and performance of the machined components, which, in turn, increase productivity. Therefore, this study investigated the effect of the multi-spindle drilling process on dimensional hole tolerances, such as hole size, circularity, cylindricity, and perpendicularity. In addition, the surface defects formed in the holes were examined using scanning electron microscopy. Three aluminium alloys, AA2024, AA6061, and AA5083, which are commonly used in the aerospace, automotive, and marine sectors, were chosen as the study materials. The results showed that the holes drilled in AA2024 gave less circularity error, cylindricity error, and perpendicularity error. In the case of hole size, the holes drilled in AA6061 were less deviated from the nominal size following holes drilled in AA2024 and AA5083 alloys. Surface damage in the form of metal debris adhesion, smeared material, side flow, and feed marks was found on the inner hole surface. Holes drilled in AA5083 alloy had the worst surface finish and were the most oversized, which was associated with noticeable damage and deformations in their inner surface. The ANOVA results revealed that the spindle speed was more influential than feed and mainly affected the hole size and cylindricity errors. However, in the case of circularity error and perpendicularity error, drilling parameters were found to be insignificant.

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Çoğun, Can. "A correlation between deviations in circularity, cylindricity, roughness and size tolerances." International Journal of Machine Tools and Manufacture 30, no. 4 (January 1990): 561–67. http://dx.doi.org/10.1016/0890-6955(90)90007-6.

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Liu, J., and Guang Lin Wang. "Pneumatic Measurement Approach for Form Tolerances of Inner Hole in Spool Valve." Applied Mechanics and Materials 42 (November 2010): 480–84. http://dx.doi.org/10.4028/www.scientific.net/amm.42.480.

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Pneumatic measurement and genetic algorithm based approach for form tolerances, including the cylindricity error, circularity error and straightness error of axis, of inner hole in spool valve are studied in this paper. A differential pressure type of pneumatic comprehensive measurement approach is put forward, which applies the pneumatic nozzle scanning measurement principle. The minimum zone evaluation and calculation approach for form tolerances based on an improved genetic algorithm is presented considering the characteristics of the measuring point. Finally, the automatic measurement experiment is developed, which can simultaneously measure and evaluate the form tolerances of inner hole in one process.

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Carr, Kirsten, and Placid Ferreira. "Verification of form tolerances part II: Cylindricity and straightness of a median line." Precision Engineering 17, no. 2 (April 1995): 144–56. http://dx.doi.org/10.1016/0141-6359(94)00018-u.

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Abbassi, Amira, Sofien Akrichi, and Noureddine Ben Yahia. "Experimental study of drilling white Calacatta–Carrara marble using artificial neural approach." Advances in Mechanical Engineering 11, no. 3 (March 2019): 168781401983357. http://dx.doi.org/10.1177/1687814019833579.

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Highly accurate marble processing is increasingly needed to comply with tight parametric/geometric tolerances and surface integrity specifications encountered while structuring, sculpture, and decorating. In this study, a new approach based on the artificial neural network technique is evaluated for the prediction of process parameters in the machining of white Calacatta–Carrara marble. The rotation speed, feed speed, drill bit diameter, drill bit height, number of pecking cycles, and drilling depth were considered as input factors. Corresponding surface roughness, hole circularity, hole cylindricity, and hole-location error were sought in output. A series of experiments was carried out using a 5-axes computer numerical control vertical machining center (OMAG) to obtain the data used for the training and testing of the artificial neural network with reasonable accuracy, under varying machining conditions. A MATLAB TM interface was developed to predict surface roughness and geometric defects (circularity, cylindricity, and localization). A 6 × 4 size multilayered neural network was developed. The number of iterations was 1000 and no smoothing factor was used. The drill quality (hole-location error, hole circularity, and hole cylindricity) and the surface roughness were modeled and evaluated individually. One hidden layer used for all models, with the number of neurons for all the responses being executed separately, was 12 while the number of neurons in the hidden layer, with all the responses executed together, was 14. In conclusion, from the obtained verified experimentally optimization results, the errors are all within acceptable ranges, which, again, confirm that the artificial neural network technique is an efficient and accurate method in predicting responses in drilling.

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Koklu, Ugur, Sezer Morkavuk, Carol Featherston, Malik Haddad, David Sanders, Muhammad Aamir, Danil Yu Pimenov, and Khaled Giasin. "The effect of cryogenic machining of S2 glass fibre composite on the hole form and dimensional tolerances." International Journal of Advanced Manufacturing Technology 115, no. 1-2 (May 3, 2021): 125–40. http://dx.doi.org/10.1007/s00170-021-07150-y.

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AbstractS2 glass fibre reinforced epoxy composites are widely used in aeronautical applications owing to their excellent strength to weight ratio. Drilling glass fibres can be cumbersome due to their abrasive nature and poor thermal conductivity. Moreover, the use of conventional coolants is not desirable due to contamination and additional costs for cleaning the machine part. An alternative is to use environmentally friendly coolants such as liquid nitrogen (LN2) which have been previously employed in machining metals and composites. The current study investigates the effect of drilling S2 glass fibre composite in a bath of LN2. The study aims to evaluate the effect of spindle speed, feed rate and the presence of cryogenic cooling on the form and dimensional tolerances of the hole (hole size, circularity, cylindricity and perpendicularity). Design of experiments and analysis of variance (ANOVA) were used to determine the contribution of the input parameters on the analysed hole quality metrics. Results indicated that drilling S2 glass fibre in a cryogenic bath increased hole size significantly beyond the nominal hole diameter. The hole circularity and cylindricity were reduced compared to holes drilled under dry condition under all cutting parameters due to enhanced thermal stability during the drilling process. The current study aims to provide the scientific and industrial communities with the necessary knowledge on whether cryogenic bath cooling strategy provides better hole quality output compared to dry drilling and other cryogenic cooling strategies which were previously reported in the open literature.

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Al-Tameemi, Hamza A., Thamir Al-Dulaimi, Michael Oluwatobiloba Awe, Shubham Sharma, Danil Yurievich Pimenov, Ugur Koklu, and Khaled Giasin. "Evaluation of Cutting-Tool Coating on the Surface Roughness and Hole Dimensional Tolerances during Drilling of Al6061-T651 Alloy." Materials 14, no. 7 (April 4, 2021): 1783. http://dx.doi.org/10.3390/ma14071783.

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Aluminum alloys are soft and have low melting temperatures; therefore, machining them often results in cut material fusing to the cutting tool due to heat and friction, and thus lowering the hole quality. A good practice is to use coated cutting tools to overcome such issues and maintain good hole quality. Therefore, the current study investigates the effect of cutting parameters (spindle speed and feed rate) and three types of cutting-tool coating (TiN/TiAlN, TiAlN, and TiN) on the surface finish, form, and dimensional tolerances of holes drilled in Al6061-T651 alloy. The study employed statistical design of experiments and ANOVA (analysis of variance) to evaluate the contribution of each of the input parameters on the measured hole-quality outputs (surface-roughness metrics Ra and Rz, hole size, circularity, perpendicularity, and cylindricity). The highest surface roughness occurred when using TiN-coated tools. All holes in this study were oversized regardless of the tool coating or cutting parameters used. TiN tools, which have a lower coating hardness, gave lower hole circularity at the entry and higher cylindricity, while TiN/TiAlN and TiAlN seemed to be more effective in reducing hole particularity when drilling at higher spindle speeds. Finally, optical microscopes revealed that a built-up edge and adhesions were most likely to form on TiN-coated tools due to TiN’s chemical affinity and low oxidation temperature compared to the TiN/TiAlN and TiAlN coatings.

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Aamir, Muhammad, Adrian Davis, William Keeble, Ugur Koklu, Khaled Giasin, Ana Vafadar, and Majid Tolouei-Rad. "The Effect of TiN-, TiCN-, TiAlN-, and TiSiN Coated Tools on the Surface Defects and Geometric Tolerances of Holes in Multi-Spindle Drilling of Al2024 Alloy." Metals 11, no. 7 (July 11, 2021): 1103. http://dx.doi.org/10.3390/met11071103.

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The integrity of machined holes depends on many parameters, some of which are related to the cutting tool (geometry, coating, material). Other influential parameters are related to the machining process variables (spindle speed, feed rate, workpiece material), all of which can affect the quality of the hole and drilling induced damage on its surface. This study investigates the effect of uncoated tools and four types of tool coatings (TiN-, TiCN-, TiAlN-, and TiSiN) on the hole quality and its microstructure. The study analyzed several hole geometrical metrics, namely hole size, circularity, cylindricity, and perpendicularity of an Al2024 aluminum alloy using a multi-spindle drilling process that utilizes three drills capable of creating multiple holes simultaneously. The results showed that the uncoated carbide drill gave a high-hole quality at low spindle speed. Regarding the coated drills, TiCN coated drills produced holes with the least deviation, circularity, cylindricity and perpendicularity at high spindle speeds. TiSiN–carbide coated drills produced the most oversized holes and noticeable damage and deformations on their surface following TiAlN and TiN. The common surface damage found on the inner hole surface was smearing, feed marks, and metal debris adhesion. The ANOVA results revealed that the tool type had the highest percentage contribution that mainly affected the hole quality.

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Pashmforoush, Farzad, Reza Farshbaf Zinati, and Davoud Maleki. "Investigation of ultrasonic vibration on thrust force, surface integrity, and geometrical tolerances during drilling of natural filler reinforced composites." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 20 (April 19, 2020): 4041–55. http://dx.doi.org/10.1177/0954406220920320.

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Growing global environmental threats have attracted researchers and engineers toward design and manufacture of green materials. In this regard, natural filler reinforced composites are environmentally friendly, cost-effective materials with a lot of advantages over conventional carbon/glass fiber reinforced composites. Hence, in this study, the drilling performance of walnut shell powder reinforced composite material was experimentally investigated. For this purpose, the composite specimens were first fabricated by injection molding process, followed by further drilling tests, which were performed with and without ultrasonic vibration. The effect of drilling parameters and ultrasonic vibration was investigated on surface roughness, thrust force and geometrical tolerances (circularity and cylindricity), as the process performance parameters. The obtained results demonstrated that by increase of the spindle rotational speed and decrease of feed rate, the thrust force, surface roughness and geometrical tolerances were reduced. Also, it was seen that ultrasonic vibration could effectively enhance the performance parameters, which was attributed to the intermittent cutting process and impact action of ultrasonic vibration, leading to reduced friction, improved material removal, reduced cutting forces, and better surface quality.

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Restivo, Maria Teresa, José Rodrigues, Maria Fátima Chouzal, Paulo Menezes, and José Almacinha. "Online Systems for Training the Evaluation of Deviations of Geometrical Characteristics." International Journal of Online and Biomedical Engineering (iJOE) 9, S8 (December 4, 2013): 16. http://dx.doi.org/10.3991/ijoe.v9is8.3355.

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In mechanical design, product manufacturing and product maintenance, geometrical characteristics such as straightness, flatness, roundness and cylindricity are very important, first in detail design with the specification of their tolerances in order to translate functional requirements into geometrical requirements and later, in the verification of the manufactured workpieces (measurement procedure) for compliance with the design objective. Coordinate Measuring Machines are very expensive equipment widely used to perform automated measurement, to inspect and to analyse engineering components in order to check their conformity with the specifications. This work presents augmented reality systems for conveying these concepts and to provide an introduction to the straightness and flatness evaluations. These systems intend to enable the users to explore the related concepts for training or educational purposes in a more immersive way.

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Sumesh, Chathakudath Sukumaran, Dawood Sheriff Akbar, Hari Shankar Purandharadass, and Raghunandan J. Chandrasekaran. "Optimization of Dimensional Tolerances and Material Removal Rate in the Orthogonal Turning of AISI 4340 Steel." Periodica Polytechnica Mechanical Engineering 65, no. 3 (July 6, 2021): 205–16. http://dx.doi.org/10.3311/ppme.16563.

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Turning is one of the most used metal removal operations in the industry. It can remove material faster, giving reasonably good surface quality apart from geometrical requirements. Conformity of geometry is one of the most significant requirements of turned components to perform their intended functions. Apart from dimensional requirements, the important geometrical necessities are Circularity, Straightness, Cylindricity, Perpendicularity, etc. Since they have a direct influence on the functioning of the components, the effect of the cutting parameters on them has greater significance. In this paper experiments are carried out to examine the effect of turning parameters such as cutting speed, feed rate, and depth of cut on responses like; straightness, roundness, surface roughness, and material removal rate during turning of AISI 4340 steel. Analysis of Variance (ANOVA) is performed and the influence of parameters on each response is studied. The optimal values of parameters obtained from the study are further confirmed by conducting experiments.

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Selvarajan, L., C. Sathiya Narayanan, and R. Jeyapaul. "Optimization of EDM Hole Drilling Parameters in Machining of MoSi2-SiC Intermetallic/Composites for Improving Geometrical Tolerances." Journal of Advanced Manufacturing Systems 14, no. 04 (September 29, 2015): 259–72. http://dx.doi.org/10.1142/s0219686715500171.

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Intermetallic/ceramic composites with multiple responses are based on L18 orthogonal array with gray relational analysis (GRA). This paper presents a new approach for the optimization of drilling parameters on drilling MoSi 2– SiC composites. Optimal machining parameters can then be determined by the gray relational grade as the performance index. In this study, the sparking parameters namely current (I), pulse on time (t on ), pulse off time (t off ), spark gap and dielectric flushing pressure (P) are optimized with considerations of multiple performance characteristics including multi responses such as material removal rate (MRR), electrode wear rate (EWR), circularity (CIR), cylindricity (CYL), perpendicularity (PER). A gray relational grade obtained from the GRA is used to solve the electrical discharge machining (EDM) process with the multiple performance characteristics. Based on the gray relational grade, optimum levels of parameters have been identified and significant contribution of parameters is determined by ANOVA. Confirmation test is conducted to validate the test result. Experimental results have shown that the responses in EDM drilling process can be improved effectively through the new approach.

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Trujillo Vilches, Francisco Javier, Sergio Martín Béjar, Carolina Bermudo Gamboa, Manuel Herrera Fernández, and Lorenzo Sevilla Hurtado. "Influence of Tool Wear on Form Deviations in Dry Machining of UNS A97075 Alloy." Metals 11, no. 6 (June 13, 2021): 958. http://dx.doi.org/10.3390/met11060958.

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Geometrical tolerances play a very important role in the functionality and assembly of parts made of light alloys for aeronautical applications. These parts are frequently machined in dry conditions. Under these conditions, the tool wear becomes one of the most important variables that influence geometrical tolerances. In this work, the influence of tool wear on roundness, straightness and cylindricity of dry-turned UNS A97075 alloy has been analyzed. The tool wear and form deviations evolution as a function of the cutting parameters and the cutting time has been assessed. In addition, the predominant tool wear mechanisms have been checked. The experimental results revealed that the indirect adhesion wear (BUL and BUE) was the main tool-wear mechanism, with the feed being the most influential cutting parameter. The combination of high feed and low cutting speed values resulted in the highest tool wear. The analyzed form deviations showed a general trend to increase with both cutting parameters. The tool wear and the form deviations tend to increase with the cutting time only within the intermediate range of feed tested. As the main novelty, a relationship between the cutting parameters, the cutting time (and, indirectly, the tool wear) and the analyzed form deviations has been found.

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Pilipović, Ana, Gorana Baršić, Marko Katić, and Maja Rujnić Havstad. "Repeatability and Reproducibility Assessment of a PolyJet Technology Using X-ray Computed Tomography." Applied Sciences 10, no. 20 (October 10, 2020): 7040. http://dx.doi.org/10.3390/app10207040.

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From the very start of their use until today, processes in Additive Manufacturing (AM) have found a way to grow from prototype production to individual and small-series production. Improvements in machinery, materials and other challenges in AM development have improved product quality, its mechanical properties and dimensional accuracy. Research in the field of dimensional accuracy must be focused on achieving better tolerances. From the beginning of AM, there has been a big issue in assuring dimensional repeatability and reproducibility of a part being printed over the course of several days. In order to examine that, a test plate was designed and built repeatedly with PolyJet technology over the course of several weeks. Measurements of dimensional accuracy and shape deviations of several typical features were carried out using X-ray Computed Tomography. Measurement results were analysed and presented in order to indicate the repeatability and reproducibility of PolyJet AM technology. Results show that PolyJet technology consistently produces parts within ±100 μm, at a 95% confidence interval, under reproducibility conditions of over a 1-month period. Accuracy for measurands (distance) in the x and y axis was significantly better than it was for the z axis which was from 56 to 197 µm, i.e., in the x and y axis, it was from −8 to 76 µm. Shape errors (i.e., cylindricity) were larger than positional or dimensional errors; this can be attributed to relatively large surface roughness and small feature sizes on the test plate that was used.

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Maurya, Nagendra K., Ashish K. Srivastava, Ambuj Saxena, Shashi P. Dwivedi, Mashood Ashraf Ali, and Jiyaul Mustafa. "Experimental investigation on the effect of laser powder bed fusion process variables on dimensional accuracy, surface roughness and cylindricity of the AlSi10Mg alloy component." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering, August 19, 2021, 095440892110390. http://dx.doi.org/10.1177/09544089211039046.

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The present study deals with the influence of laser powder bed fusion process parameters on the selected linear dimension, surface roughness and cylindricity of AlSi10Mg alloy for manufacturing of a prototype connecting rod. The process variables used in this investigation are laser power, laser velocity, layer thickness and scanning speed. Response surface methodology is used to perform experiments and data analysis. The levels of process parameters are same that is, five for all the selected input process variables. An automotive component connecting rod is used as a component to analyze the effect of process variables on selected response variables. The optimum sating of process variables are different for dimensional accuracy, surface roughness and cylindricity. Minitab 14 software is used for the data analysis. The international tolerance grades of confirmation experiments are calculated as per the ISO standard UNI EN 20286-I and DIN 16901. A quadratic regression models are developed to estimate the response variables in terms of process parameters. The model is adequate within the experimental domain. X-chart of confirmation experiments is plotted. The deviation in the linear dimension is within the limit of ±3 sigma (σ). The lowest values of response variables at the best level of process parameters are obtained, that is, percentage error in dimensional accuracy of 2.65%, surface roughness of 2.57 µm and cylindricity of 0.09 mm. The novelty of this work lies in the fact that only a few studies have been conducted related to the form errors in the archival literature.

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Agarwal, Ankit, and K. A. Desai. "Rigidity Regulation Approach for Geometric Tolerance Optimization in End Milling of Thin-Walled Components." Journal of Manufacturing Science and Engineering 143, no. 11 (June 11, 2021). http://dx.doi.org/10.1115/1.4051008.

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Abstract This article presents a novel approach to optimize geometric tolerances (flatness and cylindricity) by manipulating the rigidity among finishing and roughing cutting sequences during end milling of thin-walled components. The proposed approach considers the design configuration of the thin-walled component as an input and aims to determine semi-finished geometry such that the geometric tolerance parameters are optimized while performing a finish cutting sequence. The objective is accomplished by combining mechanistic force model, finite element (FE) analysis-based workpiece deflection model, and particle swarm optimization (PSO) technique to determine optimal disposition of material along the length of component thereby regulating rigidity. The algorithm has been validated by determining the rigidity-regulated semi-finished geometries for thin-walled components having straight, concave, and convex configurations. The outcomes of the proposed algorithm are substantiated further by conducting a set of end milling experiments for each of these cases. The results of the proposed strategy are compared with a traditional approach considering no change in the rigidity of component along length of the cut. It is demonstrated that the proposed approach can effectively optimize geometric tolerances for thin-walled components during end milling operation.

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Masoudi, Soroush, Mohammad Javad Esfahani, Farshid Jafarian, and Seyed Ali Mirsoleimani. "Comparison the Effect of MQL, Wet and Dry Turning on Surface Topography, Cylindricity Tolerance and Sustainability." International Journal of Precision Engineering and Manufacturing-Green Technology, February 20, 2019. http://dx.doi.org/10.1007/s40684-019-00042-3.

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Jafri, K., Rizauddin Ramli, and Abdul Hadi Azman. "COMPARISON OF GEOMETRICAL CHARACTERISTICS AGAINST ROTATING SHAFT VIBRATION." Jurnal Teknologi 82, no. 2 (February 4, 2020). http://dx.doi.org/10.11113/jt.v82.13813.

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Geometrical dimensioning and tolerance (GD&T) are an important element of the industry that uses high-speed rotation. Poor geometrical tolerance (GT) to components will cause the rotor to become unbalanced. Unbalanced rotor and shaft misalignment are the two major sources of vibration in the rotating system. This paper compares geometrical characteristics (GCs) to investigate the effects of vibrations generated by different GCs. Only four GC shafts were compared, straightness, parallelism, cylindricity, and concentricity, referring to the GD&T standard as ASME Y14.5-2009. These four GCs were selected owing to their direct involvement in the rotating system. Specimens are constructed with parameters of the same dimensions, length, and GT values only differ from GCs. Specimens were measured using a digital gage to find the GT value near 3000 micron at 3 mm. The magnitude of the shaft vibration during rotation was recorded using a VA-12 vibration analyzer with different rotational speeds: 510, 770, and 900 rpm. From the vibration data, the GCs’ effect on the rotation shaft will be determined. GCs are found to have significant effects on the rotation of the shaft that should be considered in the design, installation, and maintenance of rotating shafts. The impact and degree of damage to critical parts of the system can serve as a benchmark for further studies for the optimization of tolerance values and for the maintenance of component performance.

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Siraskar, Nandkumar, Ratnadeep Paul, and Sam Anand. "Adaptive Slicing in Additive Manufacturing Process Using a Modified Boundary Octree Data Structure." Journal of Manufacturing Science and Engineering 137, no. 1 (February 1, 2015). http://dx.doi.org/10.1115/1.4028579.

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In additive manufacturing (AM) processes, the layer-by-layer fabrication leads to a staircase error resulting in dimensional inaccuracies in the part surface. Using thinner slices reduces the staircase error and improves part accuracy but also increases the number of layers and the build time for manufacturing the part. Another approach called adaptive slicing uses slices of varying thicknesses based on the part geometry to build the part. A new algorithm to compute adaptive slice thicknesses using octree data structure is presented in this study. This method, termed as modified boundary octree data structure (MBODS) algorithm, is used to convert the stereolithography (STL) file of an object to an octree data structure based on the part's geometry, the machine parameters, and a user defined tolerance value. A subsequent algorithm computes the variable slice thicknesses using the MBODS representation of the part and virtually manufactures the part using these calculated slice thicknesses. Points sampled from the virtually manufactured part are inspected to evaluate the volumetric, profile, and cylindricity part errors. The MBODS based slicing algorithm is validated by comparing it with the uniform slicing approach using various slice thicknesses for different parts. The developed MBODS algorithm is observed to be more effective in improving the part quality while using lesser number of slices.

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Panhalkar, Neeraj, Ratnadeep Paul, and Sam Anand. "Increasing Part Accuracy in Additive Manufacturing Processes Using a k-d Tree Based Clustered Adaptive Layering." Journal of Manufacturing Science and Engineering 136, no. 6 (October 24, 2014). http://dx.doi.org/10.1115/1.4028586.

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Additive manufacturing (AM) is widely used in aerospace, automobile, and medical industries for building highly accurate parts using a layer by layer approach. The stereolithography (STL) file is the standard file format used in AM machines and approximates the three-dimensional (3D) model of parts using planar triangles. However, as the STL file is an approximation of the actual computer aided design (CAD) surface, the geometric errors in the final manufactured parts are pronounced, particularly in those parts with highly curved surfaces. If the part is built with the minimum uniform layer thickness allowed by the AM machine, the manufactured part will typically have the best quality, but this will also result in a considerable increase in build time. Therefore, as a compromise, the part can be built with variable layer thicknesses, i.e., using an adaptive layering technique, which will reduce the part build time while still reducing the part errors and satisfying the geometric tolerance callouts on the part. This paper describes a new approach of determining the variable slices using a 3D k-d tree method. The paper validates the proposed k-d tree based adaptive layering approach for three test parts and documents the results by comparing the volumetric, cylindricity, sphericity, and profile errors obtained from this approach with those obtained using a uniform slicing method. Since current AM machines are incapable of handling adaptive slicing approach directly, a “pseudo” grouped adaptive layering approach is also proposed here. This “clustered slicing” technique will enable the fabrication of a part in bands of varying slice thicknesses with each band having clusters of uniform slice thicknesses. The proposed k-d tree based adaptive slicing approach along with clustered slicing has been validated with simulations of the test parts of different shapes.

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Journal articles on the topic 'Cylindricity Tolerance'

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