Pub Date : 2023-11-03DOI: 10.1177/09544054231203069
Shuai Tao, Duan-Yan Wang, Sheng-Wen Zhang
Currently, manufacturing enterprises lack strict regulations and plans for complex products. The actual assembly path mainly relies on technicians’ experience, leading to an unreasonable assembly path for each part at the workstation, an unreasonable transportation path across the workstation, and the problem of mutual interference between parts. To solve these problems, this paper studies the assembly path planning technology of complex products based on the basic geometric features and assembly sequence information. The complexity of assembly path planning is reduced by converting the assembly problem into a disassembly problem. The disassembly direction and distance of each part are determined based on the geometric feature type of each mating face, and the rapid disassembly of the assembly body is achieved. The Rapidly-exploring Random Trees (RRT) algorithm is optimized by target-tendency and double random tree strategy, and the optimal assembly path of each component is quickly generated by combining the path optimization method and interference checking method. Finally, the effectiveness of the proposed method and the superiority of the path planning algorithm are verified using the cylinder head of a Marine diesel engine (MDE) as a case study.
{"title":"A feature and optimized RRT algorithm-based assembly path planning method of complex products","authors":"Shuai Tao, Duan-Yan Wang, Sheng-Wen Zhang","doi":"10.1177/09544054231203069","DOIUrl":"https://doi.org/10.1177/09544054231203069","url":null,"abstract":"Currently, manufacturing enterprises lack strict regulations and plans for complex products. The actual assembly path mainly relies on technicians’ experience, leading to an unreasonable assembly path for each part at the workstation, an unreasonable transportation path across the workstation, and the problem of mutual interference between parts. To solve these problems, this paper studies the assembly path planning technology of complex products based on the basic geometric features and assembly sequence information. The complexity of assembly path planning is reduced by converting the assembly problem into a disassembly problem. The disassembly direction and distance of each part are determined based on the geometric feature type of each mating face, and the rapid disassembly of the assembly body is achieved. The Rapidly-exploring Random Trees (RRT) algorithm is optimized by target-tendency and double random tree strategy, and the optimal assembly path of each component is quickly generated by combining the path optimization method and interference checking method. Finally, the effectiveness of the proposed method and the superiority of the path planning algorithm are verified using the cylinder head of a Marine diesel engine (MDE) as a case study.","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135873938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-03DOI: 10.1177/09544054231209792
Maojun Li, Yajie Chen, Xiaoyang Jiang, Xujing Yang
This study mainly investigated the effect of machining parameters on acoustic emission (AE) characteristics in grinding three-dimensional carbon/carbon ceramic matrix composites with superabrasive diamond grinding points. Signal processing techniques including fast Fourier transform (FFT) and short-time Fourier transform (SWFT) were applied to evaluate frequency features of AE signals. The RMS values were used as an indicator to detect grinding energy releasing characteristics. Results indicated that grinding speed and grinding depth were the main influencing factors on RMS values, while feed speed presented limited effects. The maximum undeformed chip thickness h max and active grits number were two key factors affecting RMS variation of the AE signals, which corresponded to the intensity of single AE source and the number of total AE ones, respectively. The material removal mechanisms were studied via detailed SEM micrographs of machined surfaces, revealing that fiber fracture and debonding were the main material removal modes in point grinding carbon/carbon composites. The material removal mode can be possibly identified from the frequency of AE signal, as the band of 12–35 kHz mainly corresponded to fiber fracture, 35–70 kHz referred to debonding between the fiber and matrix, 70–90 kHz indicated the frictions, and the fourth band (90–120 kHz) was related to the matrix cracks.
{"title":"Surface damage characteristics and identification based on acoustic emission in diamond point grinding carbon/carbon ceramic matrix composites","authors":"Maojun Li, Yajie Chen, Xiaoyang Jiang, Xujing Yang","doi":"10.1177/09544054231209792","DOIUrl":"https://doi.org/10.1177/09544054231209792","url":null,"abstract":"This study mainly investigated the effect of machining parameters on acoustic emission (AE) characteristics in grinding three-dimensional carbon/carbon ceramic matrix composites with superabrasive diamond grinding points. Signal processing techniques including fast Fourier transform (FFT) and short-time Fourier transform (SWFT) were applied to evaluate frequency features of AE signals. The RMS values were used as an indicator to detect grinding energy releasing characteristics. Results indicated that grinding speed and grinding depth were the main influencing factors on RMS values, while feed speed presented limited effects. The maximum undeformed chip thickness h max and active grits number were two key factors affecting RMS variation of the AE signals, which corresponded to the intensity of single AE source and the number of total AE ones, respectively. The material removal mechanisms were studied via detailed SEM micrographs of machined surfaces, revealing that fiber fracture and debonding were the main material removal modes in point grinding carbon/carbon composites. The material removal mode can be possibly identified from the frequency of AE signal, as the band of 12–35 kHz mainly corresponded to fiber fracture, 35–70 kHz referred to debonding between the fiber and matrix, 70–90 kHz indicated the frictions, and the fourth band (90–120 kHz) was related to the matrix cracks.","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"29 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135819765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-03DOI: 10.1177/09544054231205140
Shuang Ding, Xiao Zhang, Zhiwei Chen, Weiwei Wu
Geometric errors are the key error sources that affect the machining quality of a five-axis machine tool. In the case of a non-orthogonal five-axis machine tool (NOFAMT), the modelling and compensation of geometric errors can be quite complex. This paper proposes a simplified modelling algorithm to derive the analytical expressions for the position-independent geometric error (PIGE) compensation of a NOFAMT without generating higher-order error terms. First, the geometric error modelling was conducted based on the homogeneous transformation matrix (HTM). Then, algebraic expressions for PIGE compensation were obtained according to the actual inverse kinematics and a simplified algorithm. By using the simplified algorithm, the efficiency of deriving algebraic expressions for geometric error compensation can be greatly enhanced. The PIGE compensation’s numerical control (NC) codes can be directly computed using these algebraic expressions. Finally, the effectiveness and efficiency of the new algorithm were verified by numerical analysis and virtual machining. The detailed results were compared with those obtained using the differential method, and both sets of results showed the same trend.
{"title":"Position-independent geometric error compensation of a non-orthogonal five-axis machine tool using a simplified algebraic algorithm","authors":"Shuang Ding, Xiao Zhang, Zhiwei Chen, Weiwei Wu","doi":"10.1177/09544054231205140","DOIUrl":"https://doi.org/10.1177/09544054231205140","url":null,"abstract":"Geometric errors are the key error sources that affect the machining quality of a five-axis machine tool. In the case of a non-orthogonal five-axis machine tool (NOFAMT), the modelling and compensation of geometric errors can be quite complex. This paper proposes a simplified modelling algorithm to derive the analytical expressions for the position-independent geometric error (PIGE) compensation of a NOFAMT without generating higher-order error terms. First, the geometric error modelling was conducted based on the homogeneous transformation matrix (HTM). Then, algebraic expressions for PIGE compensation were obtained according to the actual inverse kinematics and a simplified algorithm. By using the simplified algorithm, the efficiency of deriving algebraic expressions for geometric error compensation can be greatly enhanced. The PIGE compensation’s numerical control (NC) codes can be directly computed using these algebraic expressions. Finally, the effectiveness and efficiency of the new algorithm were verified by numerical analysis and virtual machining. The detailed results were compared with those obtained using the differential method, and both sets of results showed the same trend.","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"24 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135819931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-03DOI: 10.1177/09544054231205333
Kashif Ishfaq, Muhammad Sana, M Saravana Kumar, Inzamam Ahmed, Che-Hua Yang
The low thermal conductivity, the small magnitude of modulus of elasticity, and the high chemical reactivity of Ti-6Al-4V make it difficult to machine this material using traditional processes. The intended requirements for the applications of the said alloy, like in biomedical and aerospace, further complicate its processing. Thereof, electric discharge machining (EDM) opted for this alloy. However, intrinsic issues of EDM, that is, electrode wear rate (EWR) and dimensional overcuts, restricted its utilization. Therefore, the potential of three powder-based additives and dielectric fluids against different electrode materials has been deeply envisaged to address the abovementioned issues. Because the choice of best dielectric has a direct bearing on heat input to the electrode which influences the melting/vaporization of the tool wear of the electrode. It is worth mentioning that these concerns have not been discussed so far in such a broad spectrum. Taguchi’s experimental design is used for experimentation. The results show that transformer oil performance is best rated compared to other dielectrics. Overall, the reduction in tool wear rate and overcut obtained with transformer oil is 21.3% and 21.4%, respectively, in contrast to the other dielectrics. The electrode of Cu outperforms for yielding the smaller value of overcut and tool wear rate. In the case of micro-additives, alumina has proved its potential for lowering the electrode wear rate. Deep and wide craters of a depth of 150 µm have been observed by using the brass electrode in kerosene oil, whereas the small and shallow craters of 38 µm depth have been encountered using the Cu electrode in the presence of transformer oil.
{"title":"Optimizing the contributing electro-erosive discharge parameters for reducing the electrode wear and geometric dimensional deviation in EDM of Ti-based superalloy","authors":"Kashif Ishfaq, Muhammad Sana, M Saravana Kumar, Inzamam Ahmed, Che-Hua Yang","doi":"10.1177/09544054231205333","DOIUrl":"https://doi.org/10.1177/09544054231205333","url":null,"abstract":"The low thermal conductivity, the small magnitude of modulus of elasticity, and the high chemical reactivity of Ti-6Al-4V make it difficult to machine this material using traditional processes. The intended requirements for the applications of the said alloy, like in biomedical and aerospace, further complicate its processing. Thereof, electric discharge machining (EDM) opted for this alloy. However, intrinsic issues of EDM, that is, electrode wear rate (EWR) and dimensional overcuts, restricted its utilization. Therefore, the potential of three powder-based additives and dielectric fluids against different electrode materials has been deeply envisaged to address the abovementioned issues. Because the choice of best dielectric has a direct bearing on heat input to the electrode which influences the melting/vaporization of the tool wear of the electrode. It is worth mentioning that these concerns have not been discussed so far in such a broad spectrum. Taguchi’s experimental design is used for experimentation. The results show that transformer oil performance is best rated compared to other dielectrics. Overall, the reduction in tool wear rate and overcut obtained with transformer oil is 21.3% and 21.4%, respectively, in contrast to the other dielectrics. The electrode of Cu outperforms for yielding the smaller value of overcut and tool wear rate. In the case of micro-additives, alumina has proved its potential for lowering the electrode wear rate. Deep and wide craters of a depth of 150 µm have been observed by using the brass electrode in kerosene oil, whereas the small and shallow craters of 38 µm depth have been encountered using the Cu electrode in the presence of transformer oil.","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"39 22","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135873404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-03DOI: 10.1177/09544054231202904
Lai Hu, Jun Zha, Peilong Song, Yaolong Chen
With the continuous development of machining methods, it is necessary to explore grinding and measuring methods to ensure the fatigue life and improved accuracy of bearings. In this study, a single-sensor three-point (SSTP) on-line outer-diameter measuring instrument was designed to ensure the consistency of the machining accuracy of precision bearing rings. Moreover, the mathematical model of the measuring instrument was established. The roundness and cylindricity error measurements of the ring outer diameter of precision bearings A and B form different manufacturers of countries were compared and analyzed. In addition, the accuracy measurement of the experimental grinder was investigated through multidimensional experiments. The results demonstrated a measuring and repetitive accuracy of ±1.25 and 1 μm, respectively. The measuring results conformed to the 3 б principle. The measured outer diameter was within the actual value of the workpiece outer diameter ±3 б, and the accuracy was over 99.73%. The instrument did only measure the outer diameter, but also measured the waviness error. The outer diameter and rotating speed did not clearly affect the measuring accuracy. The use of a lubricating fluid reduced the contact resistance of the on-line measuring instrument and significantly reduced the absolute error of outer diameter measurement, which is beneficial in improving the outer diameter measurement accuracy of the instrument.
{"title":"Single sensor three point on-line measurement method of precision rolling bearings","authors":"Lai Hu, Jun Zha, Peilong Song, Yaolong Chen","doi":"10.1177/09544054231202904","DOIUrl":"https://doi.org/10.1177/09544054231202904","url":null,"abstract":"With the continuous development of machining methods, it is necessary to explore grinding and measuring methods to ensure the fatigue life and improved accuracy of bearings. In this study, a single-sensor three-point (SSTP) on-line outer-diameter measuring instrument was designed to ensure the consistency of the machining accuracy of precision bearing rings. Moreover, the mathematical model of the measuring instrument was established. The roundness and cylindricity error measurements of the ring outer diameter of precision bearings A and B form different manufacturers of countries were compared and analyzed. In addition, the accuracy measurement of the experimental grinder was investigated through multidimensional experiments. The results demonstrated a measuring and repetitive accuracy of ±1.25 and 1 μm, respectively. The measuring results conformed to the 3 б principle. The measured outer diameter was within the actual value of the workpiece outer diameter ±3 б, and the accuracy was over 99.73%. The instrument did only measure the outer diameter, but also measured the waviness error. The outer diameter and rotating speed did not clearly affect the measuring accuracy. The use of a lubricating fluid reduced the contact resistance of the on-line measuring instrument and significantly reduced the absolute error of outer diameter measurement, which is beneficial in improving the outer diameter measurement accuracy of the instrument.","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"36 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135819896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-31DOI: 10.1177/09544054231195408
P. Mativenga
{"title":"Editorial: Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture ‘Special Issue: MATADOR 2021’","authors":"P. Mativenga","doi":"10.1177/09544054231195408","DOIUrl":"https://doi.org/10.1177/09544054231195408","url":null,"abstract":"","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"9 1","pages":"1923 - 1923"},"PeriodicalIF":2.6,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139307105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The inefficacy of the conventional methods to form Aluminium Foam Sandwich (AFS) has led to the evolution of laser forming as an alternative. However, the current literature lacks studies that demonstrate the capability of the laser forming to form a targeted part out of AFS. The current study for the first time proposed a methodology and revealed salient factors relevant to laser forming an AFS panel into a prescribed scaled-down model (bumper beam). Estimation of the scan line position and the experimental methodology to obtain the desired process parameters against each scan line to obtain the targeted part are demonstrated. Chances of failure of the AFS part during the laser forming were investigated using finite element simulation. The laser-formed part that was finally obtained conformed well to the targeted shape and also exhibited improved flexural strength with no loss of local compressibility under the three-point bending test.
{"title":"Laser forming of aluminium foam sandwich into a shock-absorbing structural part","authors":"Anirban Changdar, Ankit Shrivastava, Shitanshu Shekhar Chakraborty, Samik Dutta","doi":"10.1177/09544054231205102","DOIUrl":"https://doi.org/10.1177/09544054231205102","url":null,"abstract":"The inefficacy of the conventional methods to form Aluminium Foam Sandwich (AFS) has led to the evolution of laser forming as an alternative. However, the current literature lacks studies that demonstrate the capability of the laser forming to form a targeted part out of AFS. The current study for the first time proposed a methodology and revealed salient factors relevant to laser forming an AFS panel into a prescribed scaled-down model (bumper beam). Estimation of the scan line position and the experimental methodology to obtain the desired process parameters against each scan line to obtain the targeted part are demonstrated. Chances of failure of the AFS part during the laser forming were investigated using finite element simulation. The laser-formed part that was finally obtained conformed well to the targeted shape and also exhibited improved flexural strength with no loss of local compressibility under the three-point bending test.","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"27 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136104848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-25DOI: 10.1177/09544054231202219
Ardeshir Hemasian Etefagh, Mohammad Reza Razfar
3D bioprinting of polycaprolactone (PCL) is an additive manufacturing technique, fabricating 3D scaffolds with widespread applications in biomedical bone regeneration. PCL has favorable properties such as tunable mechanical, biological, cytocompatibility, and good printability. In addition, adding magnesium oxide (MgO) nanoparticles effectively enhance bioactivities and bone formation. However, several researchers are reported that PCL-MgO nanocomposite may face challenges in printability. Therefore, this study has focused on optimizing printing parameters to achieve enhanced mechanical and osteoconductivity properties, printability, and print resolution. A newly developed and cost-effective method, Bayesian optimization (BO), has been applied to achieve this objective. The developed model investigates and accelerates the optimization of printing parameters, including air pressure, printing speed, and nozzle temperature on printability and print resolution. Despite the wide search spaces of printing parameters, the BO model drastically reduces the number of experiments to 11 iterations in each target width. There is a good agreement between the model-predicted and actual values (91% in width). Besides, this model can be used to find optimum process parameters in printing gradient width filament to fabricate 3D gradient scaffolds.
{"title":"Bayesian optimization of 3D bioprinted polycaprolactone/magnesium oxide nanocomposite scaffold using a machine learning technique","authors":"Ardeshir Hemasian Etefagh, Mohammad Reza Razfar","doi":"10.1177/09544054231202219","DOIUrl":"https://doi.org/10.1177/09544054231202219","url":null,"abstract":"3D bioprinting of polycaprolactone (PCL) is an additive manufacturing technique, fabricating 3D scaffolds with widespread applications in biomedical bone regeneration. PCL has favorable properties such as tunable mechanical, biological, cytocompatibility, and good printability. In addition, adding magnesium oxide (MgO) nanoparticles effectively enhance bioactivities and bone formation. However, several researchers are reported that PCL-MgO nanocomposite may face challenges in printability. Therefore, this study has focused on optimizing printing parameters to achieve enhanced mechanical and osteoconductivity properties, printability, and print resolution. A newly developed and cost-effective method, Bayesian optimization (BO), has been applied to achieve this objective. The developed model investigates and accelerates the optimization of printing parameters, including air pressure, printing speed, and nozzle temperature on printability and print resolution. Despite the wide search spaces of printing parameters, the BO model drastically reduces the number of experiments to 11 iterations in each target width. There is a good agreement between the model-predicted and actual values (91% in width). Besides, this model can be used to find optimum process parameters in printing gradient width filament to fabricate 3D gradient scaffolds.","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"97 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135112128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-21DOI: 10.1177/09544054231202386
Nilesh Ashok Kharat, Ankit Agarwal, Tyler Grimm, Laine Mears
The machining of free-form components by ball-end milling inherently produces surface error in the form of scallops. The objective of any free-form toolpath strategy is to balance productivity while minimizing scallop height to reduce surface error. Conventional machining strategies produce repeatable material patterns (constant scallop height) that may limit workpiece function in areas such as lubricity, directional anisotropy, and aesthetic appearance. These strategies also involve steady-state cuts, which allow accumulation of temperature, restrict the permissible depth and speed. In the present paper a novel complex stochastic toolpath strategy has been proposed that comprises pseudo-random circular contours concatenated into a smooth path. The approach enables continuous variation of chip load, force, and direction, and avoids conditions of continuous, periodic high cutting loads and heat accumulation. Based on initial testing, it has been observed that stochastic toolpaths are longer than conventional toolpaths. However, a decrease in average cutting loads enable reduction in cutting time with feed optimization. Additionally, the proposed strategy resulted in lower scallop height than conventional machining, thereby improving surface condition.
{"title":"Investigation of stochastic toolpath strategy in three-axis ball-end milling of 2D and free-form surfaces","authors":"Nilesh Ashok Kharat, Ankit Agarwal, Tyler Grimm, Laine Mears","doi":"10.1177/09544054231202386","DOIUrl":"https://doi.org/10.1177/09544054231202386","url":null,"abstract":"The machining of free-form components by ball-end milling inherently produces surface error in the form of scallops. The objective of any free-form toolpath strategy is to balance productivity while minimizing scallop height to reduce surface error. Conventional machining strategies produce repeatable material patterns (constant scallop height) that may limit workpiece function in areas such as lubricity, directional anisotropy, and aesthetic appearance. These strategies also involve steady-state cuts, which allow accumulation of temperature, restrict the permissible depth and speed. In the present paper a novel complex stochastic toolpath strategy has been proposed that comprises pseudo-random circular contours concatenated into a smooth path. The approach enables continuous variation of chip load, force, and direction, and avoids conditions of continuous, periodic high cutting loads and heat accumulation. Based on initial testing, it has been observed that stochastic toolpaths are longer than conventional toolpaths. However, a decrease in average cutting loads enable reduction in cutting time with feed optimization. Additionally, the proposed strategy resulted in lower scallop height than conventional machining, thereby improving surface condition.","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"28 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135513128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-21DOI: 10.1177/09544054231202225
Siyuan Fu, Hong Yang, Zhong Jiang, Shouli Sun, Fang Duan
Microstructures of specified shapes have been widely applied in electronics, communication, optics, avionics, medical science, and the automotive field. The ultraprecision single-point diamond turning lathe is a core instrument used in microstructure preparation. As a key technical indicator of an ultraprecision lathe, the servo control accuracy of a system directly affects the machining accuracy of the lathe. Because the profile error of microstructures machined by the slow tool servo of the ultraprecision lathe is at the micrometer level, any disturbance reduces the accuracy of parts machining. This paper proposes a tracking error prediction model based on the force–displacement coupled servo model to study the mechanism of action for the cutting force disturbance on a servo control system. The repeated positioning error of an ultraprecision lathe’s linear axis is added to the force–displacement coupled servo model to propose a more practical profile error prediction model and analyze the effect of the cutting force on the part profile. The experimental results indicate that the force–displacement coupled servo tracking error and profile error prediction model proposed in this paper is more accurate than the existing tracking error modeling method without cutting force disturbance. In addition, this paper analyzes how the cutting force in ultraprecision machining affects the servo system and part profile, which provides a reference for subsequent ultraprecision lathe error analysis and improved machining accuracy.
{"title":"Accurate prediction method for a microstructure profile based on the force–displacement coupled servo model","authors":"Siyuan Fu, Hong Yang, Zhong Jiang, Shouli Sun, Fang Duan","doi":"10.1177/09544054231202225","DOIUrl":"https://doi.org/10.1177/09544054231202225","url":null,"abstract":"Microstructures of specified shapes have been widely applied in electronics, communication, optics, avionics, medical science, and the automotive field. The ultraprecision single-point diamond turning lathe is a core instrument used in microstructure preparation. As a key technical indicator of an ultraprecision lathe, the servo control accuracy of a system directly affects the machining accuracy of the lathe. Because the profile error of microstructures machined by the slow tool servo of the ultraprecision lathe is at the micrometer level, any disturbance reduces the accuracy of parts machining. This paper proposes a tracking error prediction model based on the force–displacement coupled servo model to study the mechanism of action for the cutting force disturbance on a servo control system. The repeated positioning error of an ultraprecision lathe’s linear axis is added to the force–displacement coupled servo model to propose a more practical profile error prediction model and analyze the effect of the cutting force on the part profile. The experimental results indicate that the force–displacement coupled servo tracking error and profile error prediction model proposed in this paper is more accurate than the existing tracking error modeling method without cutting force disturbance. In addition, this paper analyzes how the cutting force in ultraprecision machining affects the servo system and part profile, which provides a reference for subsequent ultraprecision lathe error analysis and improved machining accuracy.","PeriodicalId":20663,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture","volume":"29 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135512713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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