Pub Date : 2021-11-23DOI: 10.5545/sv-jme.2021.7318
Changbin Dong, Yongping Liu, Gang Zhao
Transmission efficiency is an important index to evaluate the transmission performance and energy consumption of gear transmission systems. To analyse the transmission efficiency of elliptic gears, the load torque fluctuation model of elliptic gear is established to analyse the influence of load torque of an elliptic gear transmission system on the torque of input and output. The torque data of input and output under different working conditions are obtained by conducting an elliptic gear transmission test. Finally, the transmission efficiency of the elliptic gear pair is obtained through the torque measurement data of the elliptic gear transmission test, and its variation law under different working conditions is analysed. The results show that the transmission efficiency of the elliptic gear transmission system changes constantly and presents an increasing trend with the increase of load torque and a decreasing trend with the increase of speed.
{"title":"A Method for Calculating Elliptic Gear Transmission Efficiency Based on Transmission Experiment","authors":"Changbin Dong, Yongping Liu, Gang Zhao","doi":"10.5545/sv-jme.2021.7318","DOIUrl":"https://doi.org/10.5545/sv-jme.2021.7318","url":null,"abstract":"Transmission efficiency is an important index to evaluate the transmission performance and energy consumption of gear transmission systems. To analyse the transmission efficiency of elliptic gears, the load torque fluctuation model of elliptic gear is established to analyse the influence of load torque of an elliptic gear transmission system on the torque of input and output. The torque data of input and output under different working conditions are obtained by conducting an elliptic gear transmission test. Finally, the transmission efficiency of the elliptic gear pair is obtained through the torque measurement data of the elliptic gear transmission test, and its variation law under different working conditions is analysed. The results show that the transmission efficiency of the elliptic gear transmission system changes constantly and presents an increasing trend with the increase of load torque and a decreasing trend with the increase of speed.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124881617","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-15DOI: 10.5545/sv-jme.2021.7220
Youyu Liu, Yi Li, Xuyou Zhang, Bo Chen
To suppress the chattering of manipulators under heavy-load operations, a control method called fuzzy equivalence & terminal sliding mode (FETSM) was applied to the trajectory tracking of motion curves for manipulators. Based on the switching term of the equivalent sliding mode (ESM), a fuzzy parameter matrix processed by the simple fuzzy rules was introduced, and the fuzzy switching term was obtained. By summing the fuzzy switching term and the equivalent term of the equivalence and a terminal sliding mode (ETSM), the control law of the FETSM for manipulators was obtained. On this basis, the stability of the system was analysed and the finite arrival time of it was deduced. On the premise of ensuring the stability of the system, the fuzzy rules and membership functions were designed for the fuzzy constants in the fuzzy switching term. Simulation tests show that the proposed FETSM can ensure sufficient trajectory-tracking precision, error convergence speed, and robustness. Compared with the ETSM, the proposed FETSM can reduce the chattering time by 94.75 % on average; compared with the proportion-integral-differential (PID) control method, the maximum chattering amplitude by the FETSM can be reduced by at least 99.21 %. Thus, the proposed FETSM is suitable for those manipulators under heavy-load operations.
{"title":"Trajectory-Tracking Control for Manipulators Based on Fuzzy Equivalence and a Terminal Sliding Mode","authors":"Youyu Liu, Yi Li, Xuyou Zhang, Bo Chen","doi":"10.5545/sv-jme.2021.7220","DOIUrl":"https://doi.org/10.5545/sv-jme.2021.7220","url":null,"abstract":"To suppress the chattering of manipulators under heavy-load operations, a control method called fuzzy equivalence & terminal sliding mode (FETSM) was applied to the trajectory tracking of motion curves for manipulators. Based on the switching term of the equivalent sliding mode (ESM), a fuzzy parameter matrix processed by the simple fuzzy rules was introduced, and the fuzzy switching term was obtained. By summing the fuzzy switching term and the equivalent term of the equivalence and a terminal sliding mode (ETSM), the control law of the FETSM for manipulators was obtained. On this basis, the stability of the system was analysed and the finite arrival time of it was deduced. On the premise of ensuring the stability of the system, the fuzzy rules and membership functions were designed for the fuzzy constants in the fuzzy switching term. Simulation tests show that the proposed FETSM can ensure sufficient trajectory-tracking precision, error convergence speed, and robustness. Compared with the ETSM, the proposed FETSM can reduce the chattering time by 94.75 % on average; compared with the proportion-integral-differential (PID) control method, the maximum chattering amplitude by the FETSM can be reduced by at least 99.21 %. Thus, the proposed FETSM is suitable for those manipulators under heavy-load operations.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116365349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-15DOI: 10.5545/sv-jme.2021.7258
Khurram Ali, A. Mehmood, Israr Muhammad, S. Razzaq, J. Iqbal
Automation technology has been extensively recognized as an emerging field in various industrial applications. Recent breakthrough in flexible automation is primarily due to deployment of robotic arms or manipulators. Autonomy in these manipulators is essentially linked with the advancements in non-linear control systems. The objective of this research is to propose a robust control algorithm for a five degree of freedom (DOF) robotic arm to achieve superior performance and reliability in the presence of friction. A friction compensation-based non-linear control has been proposed and realized for the robotic manipulator. The dynamic model of the robot has been derived by considering the dynamic friction model. The proposed three-state model is validated for all the joints of the manipulator. The integral sliding mode control (ISMC) methodology has been designed; the trajectories of system every time begin from the sliding surface and it eliminates the reaching phase with assistance of integral term in the sliding surface manifold. The designed control law has been first simulated in Matlab/Simulink environment to characterize the control performance in terms of tracking of various trajectories. The results confirm the effectiveness of the proposed control law with model-based friction compensation. The transient parameters like settling and peak time have improvement as well have better results with friction than without considering the friction. The proposed control law is then realized on an in-house developed autonomous articulated robotic rducational platform (AUTAREP) and NI myRIO hardware interfaced with LabVIEW. Experimental results also witnessed the trajectory tracking by the robotic platform.
{"title":"Control of an Anthropomorphic Manipulator using LuGre Friction Model - Design and Experimental Validation","authors":"Khurram Ali, A. Mehmood, Israr Muhammad, S. Razzaq, J. Iqbal","doi":"10.5545/sv-jme.2021.7258","DOIUrl":"https://doi.org/10.5545/sv-jme.2021.7258","url":null,"abstract":"Automation technology has been extensively recognized as an emerging field in various industrial applications. Recent breakthrough in flexible automation is primarily due to deployment of robotic arms or manipulators. Autonomy in these manipulators is essentially linked with the advancements in non-linear control systems. The objective of this research is to propose a robust control algorithm for a five degree of freedom (DOF) robotic arm to achieve superior performance and reliability in the presence of friction. A friction compensation-based non-linear control has been proposed and realized for the robotic manipulator. The dynamic model of the robot has been derived by considering the dynamic friction model. The proposed three-state model is validated for all the joints of the manipulator. The integral sliding mode control (ISMC) methodology has been designed; the trajectories of system every time begin from the sliding surface and it eliminates the reaching phase with assistance of integral term in the sliding surface manifold. The designed control law has been first simulated in Matlab/Simulink environment to characterize the control performance in terms of tracking of various trajectories. The results confirm the effectiveness of the proposed control law with model-based friction compensation. The transient parameters like settling and peak time have improvement as well have better results with friction than without considering the friction. The proposed control law is then realized on an in-house developed autonomous articulated robotic rducational platform (AUTAREP) and NI myRIO hardware interfaced with LabVIEW. Experimental results also witnessed the trajectory tracking by the robotic platform.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129107581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The fine-blanking process as an advanced sheet metal forming process has been widely applied in industry. However, specially designed equipment is required for this process. In this paper, a novel mechanical servo high-speed fine-blanking press with the capacity of 3200 kN is proposed, and the vibration control for this machine is researched to achieve the requirement of fine-blanked parts of high dimensional accuracy, since the vibration of the fine-blanking machine will cause the machining displacement error and reduce the machining accuracy. Self-adaptive feed-forward control is used to simulate the active vibration control of the mechanical fine-blanking machine. The vibration control principle of the fine-blanking machine is described, and the control algorithm is established. At the same time, the mechanical vibration model of the fine-blanking machine as the controlled object is established, and the parameters of the excitation input and the mechanical model are obtained by the fine-blanking finite element simulation and the experiments of the vibration measurement of the press. Finally, the numerical simulation and analysis of active vibration control based on MATLAB are carried out. The results show that the control effect is good, and the vibration response is effectively reduced, thus greatly increasing the processing accuracy, saving a significant amount of energy, and reducing the energy consumption and defective rate.
{"title":"Active Vibration Control of a Mechanical Servo High-speed Fine-Blanking Press","authors":"Yanxiong Liu, Yuwen Shu, Wentao Hu, Xinhao Zhao, Zhicheng Xu","doi":"10.5545/sv-jme.2020.6959","DOIUrl":"https://doi.org/10.5545/sv-jme.2020.6959","url":null,"abstract":"The fine-blanking process as an advanced sheet metal forming process has been widely applied in industry. However, specially designed equipment is required for this process. In this paper, a novel mechanical servo high-speed fine-blanking press with the capacity of 3200 kN is proposed, and the vibration control for this machine is researched to achieve the requirement of fine-blanked parts of high dimensional accuracy, since the vibration of the fine-blanking machine will cause the machining displacement error and reduce the machining accuracy. Self-adaptive feed-forward control is used to simulate the active vibration control of the mechanical fine-blanking machine. The vibration control principle of the fine-blanking machine is described, and the control algorithm is established. At the same time, the mechanical vibration model of the fine-blanking machine as the controlled object is established, and the parameters of the excitation input and the mechanical model are obtained by the fine-blanking finite element simulation and the experiments of the vibration measurement of the press. Finally, the numerical simulation and analysis of active vibration control based on MATLAB are carried out. The results show that the control effect is good, and the vibration response is effectively reduced, thus greatly increasing the processing accuracy, saving a significant amount of energy, and reducing the energy consumption and defective rate.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127092157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-15DOI: 10.5545/sv-jme.2021.7161
B. Sampath, Sureshkumar Myilsamy
In this paper, a novel method of cryogenically cooled (low-temperature nitrogen gas) wire tool is used during the oxygen-mist near-dry wire-cut electrical discharge machining (NDWEDM) process to cut Inconel 718 alloy material. The current, pulse-width, pulse-interval, and flow rate are the controllable variables for response characteristics, such as the material removal rate (MRR) and wire wear ratio (WWR). The Box-Behnken method is applied to design the experiments to collect the observations from experiments. The mathematical models for each response were developed using significant individual, interaction, and quadratic terms by the sequential sum of the square test. The response surfaces were developed. It was revealed from the analysis that 52.92 % of current, 24.63 % of Pulse-width, 12.81 % of pulse- interval and 5.75 % of flow rate contributed to MRR, while 14.89 % of current, 9.75 % of pulse-width, 62.20 % of pulse-interval, and 5.44 % of flow rate contributed to WWR. The pulse-width has more contribution on MRR due to the long period of spark between the wire and work materials. It was also observed that the pulse-interval has more effect on WWR due to the more ideal period (high spark-pause-time) between two consecutive high-temperature sparks in the wire tool. The wear of the wire tool has been analysed using scanning electron microscopy (SEM) photographs. The desirability principles were first applied to obtain multi-objective solutions with a combination of process parameters to achieve the optimal values of both responses. The predicted combination of results has been validated by data that were collected from confirmation experiments.
{"title":"Experimental Investigation of a Cryogenically Cooled Oxygen-mist Near-dry Wire-cut Electrical Discharge Machining Process","authors":"B. Sampath, Sureshkumar Myilsamy","doi":"10.5545/sv-jme.2021.7161","DOIUrl":"https://doi.org/10.5545/sv-jme.2021.7161","url":null,"abstract":"In this paper, a novel method of cryogenically cooled (low-temperature nitrogen gas) wire tool is used during the oxygen-mist near-dry wire-cut electrical discharge machining (NDWEDM) process to cut Inconel 718 alloy material. The current, pulse-width, pulse-interval, and flow rate are the controllable variables for response characteristics, such as the material removal rate (MRR) and wire wear ratio (WWR). The Box-Behnken method is applied to design the experiments to collect the observations from experiments. The mathematical models for each response were developed using significant individual, interaction, and quadratic terms by the sequential sum of the square test. The response surfaces were developed. It was revealed from the analysis that 52.92 % of current, 24.63 % of Pulse-width, 12.81 % of pulse- interval and 5.75 % of flow rate contributed to MRR, while 14.89 % of current, 9.75 % of pulse-width, 62.20 % of pulse-interval, and 5.44 % of flow rate contributed to WWR. The pulse-width has more contribution on MRR due to the long period of spark between the wire and work materials. It was also observed that the pulse-interval has more effect on WWR due to the more ideal period (high spark-pause-time) between two consecutive high-temperature sparks in the wire tool. The wear of the wire tool has been analysed using scanning electron microscopy (SEM) photographs. The desirability principles were first applied to obtain multi-objective solutions with a combination of process parameters to achieve the optimal values of both responses. The predicted combination of results has been validated by data that were collected from confirmation experiments.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133065070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-15DOI: 10.5545/sv-jme.2021.7118
Jiang Ding, A. Deng, Liwei Liu, Mengen Lu
As a kind of tiny gear based on space curve meshing theory, the line gear is very suitable for miniaturized machines due to its compact size and low weight. However, the line gear usually suffers from serious vibration problems since its line teeth are designed as twisted three-dimensional cantilevers to provide conjugated meshing curves. A dynamic model of the line gear pair is established in this paper using the numerical manifold method (NMM) to alleviate its vibration conditions, which can simultaneously provide mathematical and physical covers. The displacement function is first derived for the line teeth, and the dynamic equations of the manifold element are acquired. After inspecting the reasons that cause meshing excitation, the dynamic response of the line teeth is attained in all three orthogonal directions. The attained dynamic response shows that the vibration in the axial gear direction is more significant than that in the curvature direction. Furthermore, the vibration differential equations of the line teeth are solved through a detailed example, and the relationship between the design parameters and the natural frequency is revealed. The vibration characteristics of the first four order of the line gear are revealed through the method of NMM and compared with the result that is carried out through the commercial finite element method (FEM). The comparison shows that NMM can efficiently relieve the vibration problems of the line gear.
{"title":"Dynamic Analysis of Line Gear Pair Based on Numerical Manifold Method","authors":"Jiang Ding, A. Deng, Liwei Liu, Mengen Lu","doi":"10.5545/sv-jme.2021.7118","DOIUrl":"https://doi.org/10.5545/sv-jme.2021.7118","url":null,"abstract":"As a kind of tiny gear based on space curve meshing theory, the line gear is very suitable for miniaturized machines due to its compact size and low weight. However, the line gear usually suffers from serious vibration problems since its line teeth are designed as twisted three-dimensional cantilevers to provide conjugated meshing curves. A dynamic model of the line gear pair is established in this paper using the numerical manifold method (NMM) to alleviate its vibration conditions, which can simultaneously provide mathematical and physical covers. The displacement function is first derived for the line teeth, and the dynamic equations of the manifold element are acquired. After inspecting the reasons that cause meshing excitation, the dynamic response of the line teeth is attained in all three orthogonal directions. The attained dynamic response shows that the vibration in the axial gear direction is more significant than that in the curvature direction. Furthermore, the vibration differential equations of the line teeth are solved through a detailed example, and the relationship between the design parameters and the natural frequency is revealed. The vibration characteristics of the first four order of the line gear are revealed through the method of NMM and compared with the result that is carried out through the commercial finite element method (FEM). The comparison shows that NMM can efficiently relieve the vibration problems of the line gear.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"22 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114046482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-15DOI: 10.5545/sv-jme.2021.7203
A. Bhatia, Reeta Wattal
The present study focuses on improving the ultimate tensile strength of friction stir welded carbon steel (AISI 1018). The effect of the process parameters (welding speed, tool RPM, and shoulder diameter) on the response parameters (ultimate tensile strength, percentage elongation and percentage reduction in area) were studied. Response surface methodology was used to develop the mathematical model for response parameters, and the adequacy of the model was checked using analysis of variance (ANOVA). The welding speed and tool RPM were found to affect the ultimate tensile strength significantly. The percentage elongation was affected only by welding speed. The percentage reduction in the area was affected by welding speed and shoulder diameter. The microstructure and microhardness of the weld have been studied and reported in the study.
{"title":"Process Parameters Optimization for Maximizing Tensile Strength in Friction Stir-Welded Carbon Steel","authors":"A. Bhatia, Reeta Wattal","doi":"10.5545/sv-jme.2021.7203","DOIUrl":"https://doi.org/10.5545/sv-jme.2021.7203","url":null,"abstract":"The present study focuses on improving the ultimate tensile strength of friction stir welded carbon steel (AISI 1018). The effect of the process parameters (welding speed, tool RPM, and shoulder diameter) on the response parameters (ultimate tensile strength, percentage elongation and percentage reduction in area) were studied. Response surface methodology was used to develop the mathematical model for response parameters, and the adequacy of the model was checked using analysis of variance (ANOVA). The welding speed and tool RPM were found to affect the ultimate tensile strength significantly. The percentage elongation was affected only by welding speed. The percentage reduction in the area was affected by welding speed and shoulder diameter. The microstructure and microhardness of the weld have been studied and reported in the study.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133936390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-26DOI: 10.5545/SV-JME.2021.7104
A. Mohammed, H. Lemu, Belete Sirahbizu
The design of a windmill rotor is critical for harnessing wind energy. In this work, a study is conducted to optimize the design and performance of a rotor blade that is suitable for low wind conditions. The windmills’ rotor blades are aerodynamically designed based on the SG6043 airfoil and wind speed data at local selected sites. The aerodynamic profile of the rotor blade that can provide a maximum power coefficient, which is the relation between real rotor performance and the available wind energy on a given reference area, was calculated. Different parameters, such as blade shapes, chord distributions, tip speed ratio, geometries set angles, etc., were used to optimize the blade design with the objective of extracting maximum wind power for a water pumping system. Windmill rotor of 10.74 m, 7.34 m, and 6.34 m diameter with three blades were obtained for the selected sites at Abomsa, Metehara, and Ziway in south-east Ethiopia. During the rotary blades performance optimization, blade element momentum (BEM) theory and solving iteration by MATLAB® coding were used.
{"title":"Determining Optimum Rotary Blade Design for Wind-Powered Water-Pumping Systems for Local Selected Sites","authors":"A. Mohammed, H. Lemu, Belete Sirahbizu","doi":"10.5545/SV-JME.2021.7104","DOIUrl":"https://doi.org/10.5545/SV-JME.2021.7104","url":null,"abstract":"The design of a windmill rotor is critical for harnessing wind energy. In this work, a study is conducted to optimize the design and performance of a rotor blade that is suitable for low wind conditions. The windmills’ rotor blades are aerodynamically designed based on the SG6043 airfoil and wind speed data at local selected sites. The aerodynamic profile of the rotor blade that can provide a maximum power coefficient, which is the relation between real rotor performance and the available wind energy on a given reference area, was calculated. Different parameters, such as blade shapes, chord distributions, tip speed ratio, geometries set angles, etc., were used to optimize the blade design with the objective of extracting maximum wind power for a water pumping system. Windmill rotor of 10.74 m, 7.34 m, and 6.34 m diameter with three blades were obtained for the selected sites at Abomsa, Metehara, and Ziway in south-east Ethiopia. During the rotary blades performance optimization, blade element momentum (BEM) theory and solving iteration by MATLAB® coding were used.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125891623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-26DOI: 10.5545/SV-JME.2021.7113
Mohsen Soori, Mohammed Asmael
To simulate and analyse the real machined parts in virtual environments, virtual machining systems are applied to the production processes. Due to friction, chip forming, and the heat produced in the cutting zone, parts produced using machining operation have residual stress effects. The machining force and machining temperature can cause the deflection error in the machined turbine blades, which should be minimized to increase the accuracy of machined blades. To minimize the residual stress and deflection error of machined parts, optimized machining parameters can be obtained. In the present research work, the application of a virtual machining system is presented to predict and minimize the residual stress and deflection error in a five-axis milling operations of turbine blades. In order to predict the residual stress and deflection error in machined turbine blades, finite element analysis is implemented. Moreover, to minimize the residual stress and deflection error in machined turbine blades, optimized parameters of machining operations are obtained by using a genetic algorithm. To validate the research work, experimentally determining residual stress by using a X-ray diffraction method from the machined turbine blades is compared with the finite element results obtained from the virtual machining system. Also, in order to obtain the deflection error, the machined blades are measured by using the CMM machines. Thus, the accuracy and reliability of machined turbine blades can be increased by analysing and minimizing the residual stress and deflection error in virtual environments.
{"title":"Virtual Minimization of Residual Stress and Deflection Error in the Five-Axis Milling of Turbine Blades","authors":"Mohsen Soori, Mohammed Asmael","doi":"10.5545/SV-JME.2021.7113","DOIUrl":"https://doi.org/10.5545/SV-JME.2021.7113","url":null,"abstract":"To simulate and analyse the real machined parts in virtual environments, virtual machining systems are applied to the production processes. Due to friction, chip forming, and the heat produced in the cutting zone, parts produced using machining operation have residual stress effects. The machining force and machining temperature can cause the deflection error in the machined turbine blades, which should be minimized to increase the accuracy of machined blades. To minimize the residual stress and deflection error of machined parts, optimized machining parameters can be obtained. In the present research work, the application of a virtual machining system is presented to predict and minimize the residual stress and deflection error in a five-axis milling operations of turbine blades. In order to predict the residual stress and deflection error in machined turbine blades, finite element analysis is implemented. Moreover, to minimize the residual stress and deflection error in machined turbine blades, optimized parameters of machining operations are obtained by using a genetic algorithm. To validate the research work, experimentally determining residual stress by using a X-ray diffraction method from the machined turbine blades is compared with the finite element results obtained from the virtual machining system. Also, in order to obtain the deflection error, the machined blades are measured by using the CMM machines. Thus, the accuracy and reliability of machined turbine blades can be increased by analysing and minimizing the residual stress and deflection error in virtual environments.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133506479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-26DOI: 10.5545/SV-JME.2020.7094
I. Okorn, M. Nagode, J. Klemenc
In practical use, most gears have an involute shape of tooth flanks. However, external involute gears have some drawbacks, such as unfavourable kinematic conditions at the beginning and end of meshing, a limited minimum number of teeth, and the highly loaded convex-convex (i.e., non-conformal) contact. Researchers have developed and analysed various non-involute forms of tooth flanks, but they have not been widely accepted. The main reasons are higher manufacturing costs and sensitivity to manufacturing and assembly errors. Analyses of non-involute forms of teeth are mostly theoretical (analytical and numerical), while there is a lack of experimental confirmations of theoretical assumptions. This paper reviews external non-involute shapes, their operating characteristics and possibilities of use compared to involute gears. Established criteria, such as Hertzian pressure, oil film thickness, bending stress at the root of the tooth, contact temperature, and gear noise, were used for assessment. The results of analytical studies and experimental research on S-gears are presented in more detail. S-gears have a higher surface durability and a lower heat load when compared to involute gears. The usability of non-involute gears is increasing with the development of new technologies and materials. However, the advantages of non-involute shapes are not so significant that they could easily displace involute gears, which are cheaper to manufacture.
{"title":"Operating Performance of External Non-Involute Spur˝and Helical Gears: A Review","authors":"I. Okorn, M. Nagode, J. Klemenc","doi":"10.5545/SV-JME.2020.7094","DOIUrl":"https://doi.org/10.5545/SV-JME.2020.7094","url":null,"abstract":"In practical use, most gears have an involute shape of tooth flanks. However, external involute gears have some drawbacks, such as unfavourable kinematic conditions at the beginning and end of meshing, a limited minimum number of teeth, and the highly loaded convex-convex (i.e., non-conformal) contact. Researchers have developed and analysed various non-involute forms of tooth flanks, but they have not been widely accepted. The main reasons are higher manufacturing costs and sensitivity to manufacturing and assembly errors. Analyses of non-involute forms of teeth are mostly theoretical (analytical and numerical), while there is a lack of experimental confirmations of theoretical assumptions. This paper reviews external non-involute shapes, their operating characteristics and possibilities of use compared to involute gears. Established criteria, such as Hertzian pressure, oil film thickness, bending stress at the root of the tooth, contact temperature, and gear noise, were used for assessment. The results of analytical studies and experimental research on S-gears are presented in more detail. S-gears have a higher surface durability and a lower heat load when compared to involute gears. The usability of non-involute gears is increasing with the development of new technologies and materials. However, the advantages of non-involute shapes are not so significant that they could easily displace involute gears, which are cheaper to manufacture.","PeriodicalId":135907,"journal":{"name":"Strojniški vestnik – Journal of Mechanical Engineering","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125125405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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