In order to achieve a good match between magnetorheological (MR) damper and vehicle Noise Vibration and Harshness (NVH) quality and improve vehicle posture while driving, an integrated design method of MR damper structure/control for vehicle vibration suppression was proposed considering the coupling effect between MR damper structure parameters and controller parameters. A controller was designed to control the damping force generated by the tapered channel MR damper. Furthermore, the damping force expression of the tapered flow mode MR damper was derived, and the damping force was introduced into the vehicle dynamics model. In order to improve the vehicle posture, an integrated structure/control platform combining response surface model, current controller and vehicle dynamics model was established. Based on integrated platform, the vehicle dynamics model and Fourier transform were adopted to extract the time-frequency characteristics of the design objective under different working conditions. In the optimization process, the damper structure was optimized by taking the time domain values as the constraints and the frequency domain values as the optimization goals. The results show that the proposed integrated design method of MR damper can obtain its global optimal structural parameters under different driving conditions. The acceleration root mean square (RMS) values and frequency domain values of vehicle were both reduced to varying degrees, achieving the purpose of improving the vehicle posture.
{"title":"Study on the integrated structure/control design method of magnetorheological damper for improving vehicle posture","authors":"Zhaoxue Deng, Xinxin Wei, Xingquan Li, Shuen Zhao, Sunke Zhu","doi":"10.1177/14644193221090868","DOIUrl":"https://doi.org/10.1177/14644193221090868","url":null,"abstract":"In order to achieve a good match between magnetorheological (MR) damper and vehicle Noise Vibration and Harshness (NVH) quality and improve vehicle posture while driving, an integrated design method of MR damper structure/control for vehicle vibration suppression was proposed considering the coupling effect between MR damper structure parameters and controller parameters. A controller was designed to control the damping force generated by the tapered channel MR damper. Furthermore, the damping force expression of the tapered flow mode MR damper was derived, and the damping force was introduced into the vehicle dynamics model. In order to improve the vehicle posture, an integrated structure/control platform combining response surface model, current controller and vehicle dynamics model was established. Based on integrated platform, the vehicle dynamics model and Fourier transform were adopted to extract the time-frequency characteristics of the design objective under different working conditions. In the optimization process, the damper structure was optimized by taking the time domain values as the constraints and the frequency domain values as the optimization goals. The results show that the proposed integrated design method of MR damper can obtain its global optimal structural parameters under different driving conditions. The acceleration root mean square (RMS) values and frequency domain values of vehicle were both reduced to varying degrees, achieving the purpose of improving the vehicle posture.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80985741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-02-16DOI: 10.1177/14644193221076348
Hanwen Xu, X. Xiao, Qi Wang, Jian Han, Xue-song Jin
To study the ride comfort of high-speed train passengers, a detailed human body–seat–vehicle–track coupled model is developed. This model adopts a dual-axis human-body dynamic model and considers the nonlinearity of the primary and secondary suspensions and the wheel–rail contact condition. Additionally, the input wheel/rail irregularity excitation data are measured for a high-speed railway line in China. According to the model, the root-mean-square (RMS) values of the acceleration for the passenger head at different positions of the car body are determined, and the effects of the car-body loading conditions, speed, and seat support parameters on the head vibration characteristics are studied. The results indicate that the RMS value is the highest for the passengers sitting in the front row near the window seat, followed by those sitting in the middle row of the car body. There are small differences in the RMS value between the passengers sitting on the left and right sides of the same row in the car body. At a certain speed, the track irregularity stimulates the rolling and pitching motions of the train. Therefore, effective methods should be implemented to avoid the inherent characteristics of the car body. Although an increase in the seat support stiffness intensifies the high-frequency vibration, it reduces the low-frequency vibration in the range of 0–15 Hz, reducing the RMS value of the head acceleration. When the train is loaded, the effect of passengers on the car body is similar to that of a damper or mass element, which can reduce the car-body vibration and enhance the ride comfort.
{"title":"Preliminary analysis of vibration characteristics of human body on high-speed train","authors":"Hanwen Xu, X. Xiao, Qi Wang, Jian Han, Xue-song Jin","doi":"10.1177/14644193221076348","DOIUrl":"https://doi.org/10.1177/14644193221076348","url":null,"abstract":"To study the ride comfort of high-speed train passengers, a detailed human body–seat–vehicle–track coupled model is developed. This model adopts a dual-axis human-body dynamic model and considers the nonlinearity of the primary and secondary suspensions and the wheel–rail contact condition. Additionally, the input wheel/rail irregularity excitation data are measured for a high-speed railway line in China. According to the model, the root-mean-square (RMS) values of the acceleration for the passenger head at different positions of the car body are determined, and the effects of the car-body loading conditions, speed, and seat support parameters on the head vibration characteristics are studied. The results indicate that the RMS value is the highest for the passengers sitting in the front row near the window seat, followed by those sitting in the middle row of the car body. There are small differences in the RMS value between the passengers sitting on the left and right sides of the same row in the car body. At a certain speed, the track irregularity stimulates the rolling and pitching motions of the train. Therefore, effective methods should be implemented to avoid the inherent characteristics of the car body. Although an increase in the seat support stiffness intensifies the high-frequency vibration, it reduces the low-frequency vibration in the range of 0–15 Hz, reducing the RMS value of the head acceleration. When the train is loaded, the effect of passengers on the car body is similar to that of a damper or mass element, which can reduce the car-body vibration and enhance the ride comfort.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87966678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-02-15DOI: 10.1177/14644193221078656
Rajesh K Bhamu, Aakash Shukla, Satish C. Sharma, S. Harsha
In the present paper, vibration responses of the healthy and cracked blade under the influence of stress-stiffening and spin-softening have been studied. The three-dimensional finite element-based numerical analysis is carried out to study the blade's mode shape and natural frequencies and are validated with the experimental modal analysis test results. In the case of spin softening, for healthy blade at the turbine’s speed over 1000 RPM, natural frequencies increase significantly in both first flap-wise and chordwise bending modes. In both cases of STF and SOF, for the cracked blade, the deviation from the healthy blade in the natural frequency increases with increasing crack size, maximal in a crack size of 90%. It is also observed that irrespective of crack size, deviation in natural frequencies as compared to healthy blade increases as spin speed increases in the cases of chordwise bending mode (Mode II) and higher-order overlapped mode IV, and in the case of fundamental torsion mode (Mode III), higher-order overlapped mode V and VI natural frequencies decrease in both STF and SOF cases.
{"title":"Vibration Response of Steam Turbine Healthy and Cracked Blade under the Stress Stiffening and Spin Softening Effects","authors":"Rajesh K Bhamu, Aakash Shukla, Satish C. Sharma, S. Harsha","doi":"10.1177/14644193221078656","DOIUrl":"https://doi.org/10.1177/14644193221078656","url":null,"abstract":"In the present paper, vibration responses of the healthy and cracked blade under the influence of stress-stiffening and spin-softening have been studied. The three-dimensional finite element-based numerical analysis is carried out to study the blade's mode shape and natural frequencies and are validated with the experimental modal analysis test results. In the case of spin softening, for healthy blade at the turbine’s speed over 1000 RPM, natural frequencies increase significantly in both first flap-wise and chordwise bending modes. In both cases of STF and SOF, for the cracked blade, the deviation from the healthy blade in the natural frequency increases with increasing crack size, maximal in a crack size of 90%. It is also observed that irrespective of crack size, deviation in natural frequencies as compared to healthy blade increases as spin speed increases in the cases of chordwise bending mode (Mode II) and higher-order overlapped mode IV, and in the case of fundamental torsion mode (Mode III), higher-order overlapped mode V and VI natural frequencies decrease in both STF and SOF cases.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82600228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-02-07DOI: 10.1177/14644193221077494
Changbin Dong, Yongping Liu
The transmission error of the gear transmission system is the main factor affecting its transmission performance. The expansion of special applications of elliptic gear transmission system and the improvement of transmission accuracy requirements put forward higher requirements for its transmission performance. Although many works have been presented to study the transmission error of cylindrical gear transmission system, a few works were focused on the transmission error of elliptic gears for the reason of the inconsistency of the tooth profile of the elliptic gear pair, the difficulty of establishing a transmission error model and obtaining the dynamic backlash. To overcome this problem, the theoretical model of the transmission error and backlash of the elliptic gear pair is proposed and established based on the meshing line incremental method. The ellipse gear transmission test-rig is built and the transmission test is carried out on it. Finally, the correctness of the theoretical model is verified. The results show that the dynamic backlash of the elliptic gear pair can be obtained through the bidirectional transmission error curve. The dynamic transmission error has a negative correlation with the speed and has a positive correlation with the load torque. The dynamic backlash shows an increasing relationship with the increase of speed and load torque. The research results of this article can provide a certain theoretical basis for the anti-backlash control of the elliptic gear transmission system and the improvement of transmission performance.
{"title":"Experimental study on transmission error and dynamic backlash of elliptic gear transmission system","authors":"Changbin Dong, Yongping Liu","doi":"10.1177/14644193221077494","DOIUrl":"https://doi.org/10.1177/14644193221077494","url":null,"abstract":"The transmission error of the gear transmission system is the main factor affecting its transmission performance. The expansion of special applications of elliptic gear transmission system and the improvement of transmission accuracy requirements put forward higher requirements for its transmission performance. Although many works have been presented to study the transmission error of cylindrical gear transmission system, a few works were focused on the transmission error of elliptic gears for the reason of the inconsistency of the tooth profile of the elliptic gear pair, the difficulty of establishing a transmission error model and obtaining the dynamic backlash. To overcome this problem, the theoretical model of the transmission error and backlash of the elliptic gear pair is proposed and established based on the meshing line incremental method. The ellipse gear transmission test-rig is built and the transmission test is carried out on it. Finally, the correctness of the theoretical model is verified. The results show that the dynamic backlash of the elliptic gear pair can be obtained through the bidirectional transmission error curve. The dynamic transmission error has a negative correlation with the speed and has a positive correlation with the load torque. The dynamic backlash shows an increasing relationship with the increase of speed and load torque. The research results of this article can provide a certain theoretical basis for the anti-backlash control of the elliptic gear transmission system and the improvement of transmission performance.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86725663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-01-19DOI: 10.1177/14644193211072612
Jin Gao, X. Qi
This study focuses on the influence of steering system stiffness and damping on the vehicle transient characteristics at two different types of handling frequencies, and optimizes the vehicle transient characteristics with steering system stiffness and damping as optimization variables at both handling frequencies. The kinematic relationship between wheel angle and steering wheel angle is derived as well as a detailed analysis of the forces on the steering linkage. The differential equations of vehicle dynamics are developed to explain the influence of steering system stiffness and damping on the vehicle transient characteristics theoretically. The stiffness and damping, which have a significant influence on the vehicle transient characteristics, are selected by sensitivity analysis and used as variables for simulation verification. Simulation results show that the influence of steering system stiffness and damping on vehicle transient characteristics is different at high handling frequencies and low handling frequencies. The stiffness and damping are used as optimization variables and the objective evaluation indexes of vehicle transient characteristics at high handling frequencies and low handling frequencies are used as optimization targets for multi-objective optimization by the NSGA-II optimization algorithm. The optimization results show that: The yaw rate gain relative to steering wheel angle and the delay time of lateral acceleration relative to steering wheel angle are improved at both low and high frequencies.
{"title":"Analysis and optimization of vehicle transient characteristics under sine-swept steering input with considering steering system stiffness and damping","authors":"Jin Gao, X. Qi","doi":"10.1177/14644193211072612","DOIUrl":"https://doi.org/10.1177/14644193211072612","url":null,"abstract":"This study focuses on the influence of steering system stiffness and damping on the vehicle transient characteristics at two different types of handling frequencies, and optimizes the vehicle transient characteristics with steering system stiffness and damping as optimization variables at both handling frequencies. The kinematic relationship between wheel angle and steering wheel angle is derived as well as a detailed analysis of the forces on the steering linkage. The differential equations of vehicle dynamics are developed to explain the influence of steering system stiffness and damping on the vehicle transient characteristics theoretically. The stiffness and damping, which have a significant influence on the vehicle transient characteristics, are selected by sensitivity analysis and used as variables for simulation verification. Simulation results show that the influence of steering system stiffness and damping on vehicle transient characteristics is different at high handling frequencies and low handling frequencies. The stiffness and damping are used as optimization variables and the objective evaluation indexes of vehicle transient characteristics at high handling frequencies and low handling frequencies are used as optimization targets for multi-objective optimization by the NSGA-II optimization algorithm. The optimization results show that: The yaw rate gain relative to steering wheel angle and the delay time of lateral acceleration relative to steering wheel angle are improved at both low and high frequencies.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89854435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2022-01-11DOI: 10.1177/14644193211073016
E. Rocca, R. Russo
The paper reports a numerical investigation on the dynamic behaviour of a vehicle driveline, equipped with a Torsional Vibration Damper (TVD) based on Magneto-Rheological Elastomeric (MRE) spring elements, during the start-up transient considering an abrupt manoeuvre of clutch engagement. The TVD device consists of a flywheel and a damper disk, with interposed some elastomeric samples which react for relative angular displacements of the two disks. The dynamical parameters of the TVD can be properly tuned by varying the magnetic field surrounding the MRE springs to mitigate the torsional oscillations of the flywheel, causes of many undesired inconveniences as critical speeds or vibro-acoustic issues. The present study promotes the use of the MRE torsional vibration damper to reduce the annoying vibroacoustic phenomenon of “gear rattle” arising in the unloaded gear pairs of the gear box, during and after the rapid clutch engagement transients in the vehicle start-up phase and is conducted on a simplified automotive driveline equipped with a dry clutch. The possibility of quickly tuning the mechanical properties of the MRE-TVD, makes this device particularly eligible for suppressing the above disturbance, adapting to the various operative conditions of the automotive driveline. Results of the analysis, by the help of a Gear Rattle Index (GRI), demonstrate the effectiveness of the proposed device in reducing the vibroacoustic phenomenon during the transient phases of the vehicle start-up, until the vehicles speed conditions are reached.
{"title":"Gear Rattle during a start-up transient in a driveline equipped with a tuneable torsional Vibration Damper with Magneto-Rheological Elastomers","authors":"E. Rocca, R. Russo","doi":"10.1177/14644193211073016","DOIUrl":"https://doi.org/10.1177/14644193211073016","url":null,"abstract":"The paper reports a numerical investigation on the dynamic behaviour of a vehicle driveline, equipped with a Torsional Vibration Damper (TVD) based on Magneto-Rheological Elastomeric (MRE) spring elements, during the start-up transient considering an abrupt manoeuvre of clutch engagement. The TVD device consists of a flywheel and a damper disk, with interposed some elastomeric samples which react for relative angular displacements of the two disks. The dynamical parameters of the TVD can be properly tuned by varying the magnetic field surrounding the MRE springs to mitigate the torsional oscillations of the flywheel, causes of many undesired inconveniences as critical speeds or vibro-acoustic issues. The present study promotes the use of the MRE torsional vibration damper to reduce the annoying vibroacoustic phenomenon of “gear rattle” arising in the unloaded gear pairs of the gear box, during and after the rapid clutch engagement transients in the vehicle start-up phase and is conducted on a simplified automotive driveline equipped with a dry clutch. The possibility of quickly tuning the mechanical properties of the MRE-TVD, makes this device particularly eligible for suppressing the above disturbance, adapting to the various operative conditions of the automotive driveline. Results of the analysis, by the help of a Gear Rattle Index (GRI), demonstrate the effectiveness of the proposed device in reducing the vibroacoustic phenomenon during the transient phases of the vehicle start-up, until the vehicles speed conditions are reached.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2022-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88942455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2021-12-30DOI: 10.1177/14644193211051173
Yi Lu, Zefeng Chang, Nijia Ye
When a heavy object is cooperatively grasped to move by several fingers of the robot hybrid hand, the inertial properties and the mass distribution of the object must influence largely on the operation precision, grasping stability, and the safety of both the hybrid hand and the object. Hence, it is an important and significant issue to establish and analyze the dynamics model of the moving-object cooperatively grasped by the hybrid hand in order to ensure the safety and grasping stability of the hybrid hand and the object. However, this research has not been conducted. In this paper, a dynamics model of the moving-object grasped by the hybrid hand is established, and its dynamics is studied and analyzed. First, a three-dimensional model of a hybrid hand formed by a novel parallel manipulator and three fingers is designed for cooperatively grasping object. Second, the kinematic formulas for solving the Jacobian matrices, the Hessian matrices, the general velocity/acceleration of the moving platform, and four active limbs of the parallel manipulator are derived. Third, the composite Jacobian matrix and the composite Hessian matrix of the hybrid hand are derived, and the general velocity/acceleration of the moving-object grasped by the hybrid hand is derived. Fourth, dynamics model of the hybrid hand is established, the formulas for solving the dynamic actuation forces of the three fingers and the dynamic actuation forces/torque and constrained forces of the parallel manipulator are derived. Finally, the theoretical solutions of the dynamics model of the moving-object grasped by the hybrid hand are verified by its simulation mechanism.
{"title":"Dynamics of moving-object grasped by a hybrid hand","authors":"Yi Lu, Zefeng Chang, Nijia Ye","doi":"10.1177/14644193211051173","DOIUrl":"https://doi.org/10.1177/14644193211051173","url":null,"abstract":"When a heavy object is cooperatively grasped to move by several fingers of the robot hybrid hand, the inertial properties and the mass distribution of the object must influence largely on the operation precision, grasping stability, and the safety of both the hybrid hand and the object. Hence, it is an important and significant issue to establish and analyze the dynamics model of the moving-object cooperatively grasped by the hybrid hand in order to ensure the safety and grasping stability of the hybrid hand and the object. However, this research has not been conducted. In this paper, a dynamics model of the moving-object grasped by the hybrid hand is established, and its dynamics is studied and analyzed. First, a three-dimensional model of a hybrid hand formed by a novel parallel manipulator and three fingers is designed for cooperatively grasping object. Second, the kinematic formulas for solving the Jacobian matrices, the Hessian matrices, the general velocity/acceleration of the moving platform, and four active limbs of the parallel manipulator are derived. Third, the composite Jacobian matrix and the composite Hessian matrix of the hybrid hand are derived, and the general velocity/acceleration of the moving-object grasped by the hybrid hand is derived. Fourth, dynamics model of the hybrid hand is established, the formulas for solving the dynamic actuation forces of the three fingers and the dynamic actuation forces/torque and constrained forces of the parallel manipulator are derived. Finally, the theoretical solutions of the dynamics model of the moving-object grasped by the hybrid hand are verified by its simulation mechanism.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81780451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2021-12-30DOI: 10.1177/14644193211055886
Duy-Chinh Nguyen
In reality, a pendulum structure can be used to model many real structures as a ropeway carrier, crane, balloon basket or ships in waves, etc, which often hung on moving points such as cables, wavefronts and balloons, etc. To the best knowledge of the author, however, there is no study to control oscillation of the pendulum structure excited by the hanging point. Therefore, this article deals with the oscillation control of the pendulum structure by using an inverted pendulum-type tuned mass damper, in which the system is subjected to the motion of the hanging point. In particular, the optimal parameters are determined in clear analytical solutions, making it easy for scientists to determine the optimal parameters to suppress the oscillation for the pendulum structure.
{"title":"Oscillation control of a pendulum structure using an inverted pendulum-type tuned mass damper","authors":"Duy-Chinh Nguyen","doi":"10.1177/14644193211055886","DOIUrl":"https://doi.org/10.1177/14644193211055886","url":null,"abstract":"In reality, a pendulum structure can be used to model many real structures as a ropeway carrier, crane, balloon basket or ships in waves, etc, which often hung on moving points such as cables, wavefronts and balloons, etc. To the best knowledge of the author, however, there is no study to control oscillation of the pendulum structure excited by the hanging point. Therefore, this article deals with the oscillation control of the pendulum structure by using an inverted pendulum-type tuned mass damper, in which the system is subjected to the motion of the hanging point. In particular, the optimal parameters are determined in clear analytical solutions, making it easy for scientists to determine the optimal parameters to suppress the oscillation for the pendulum structure.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91113337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2021-12-23DOI: 10.1177/14644193211065916
Jing Liu, Chenyu An, G. Pan
The nonlinear contact forces and deformations between the balls and raceways can cause very complex vibration behaviours of rotor systems with the waviness in the support bearings. However, almost all previous works that used sinusoidal waviness took the Hertzian solution as the calculation method, which is not an accurate method based on Johnson’s formulation since the changes in the curvature at the sinusoidal contact surfaces. To overcome this issue, a new dynamic model of a rigid rotor system with the waviness in the support bearings is proposed. To provide a more accurate nonlinear contact force formulation for the sinusoidal waviness profile, the model used the Johnson’s extended Hertzian contact model to replace Hertzian contact model. This model can consider the time-varying curvature between the mating sinusoidal surfaces. The lubricating condition in the support bearing is also considered. A comparative study on the effects of Hertzian contact model, simplified Hertzian contact model, and Johnson's extended Hertzian contact model on the nonlinear vibrations of the rotor system is developed. The effects of the waviness amplitude and orders on the vibrations of the rotor system are discussed. The comparative simulations show that the proposed model can provide a more reasonable approach for predicting the vibrations of the rigid rotor system. Moreover, the simulations give that the nonlinear contact forces in the support bearings can greatly affect the system vibrations.
{"title":"A vibration model of a rotor system with the sinusoidal waviness by using the non-Hertzian solution","authors":"Jing Liu, Chenyu An, G. Pan","doi":"10.1177/14644193211065916","DOIUrl":"https://doi.org/10.1177/14644193211065916","url":null,"abstract":"The nonlinear contact forces and deformations between the balls and raceways can cause very complex vibration behaviours of rotor systems with the waviness in the support bearings. However, almost all previous works that used sinusoidal waviness took the Hertzian solution as the calculation method, which is not an accurate method based on Johnson’s formulation since the changes in the curvature at the sinusoidal contact surfaces. To overcome this issue, a new dynamic model of a rigid rotor system with the waviness in the support bearings is proposed. To provide a more accurate nonlinear contact force formulation for the sinusoidal waviness profile, the model used the Johnson’s extended Hertzian contact model to replace Hertzian contact model. This model can consider the time-varying curvature between the mating sinusoidal surfaces. The lubricating condition in the support bearing is also considered. A comparative study on the effects of Hertzian contact model, simplified Hertzian contact model, and Johnson's extended Hertzian contact model on the nonlinear vibrations of the rotor system is developed. The effects of the waviness amplitude and orders on the vibrations of the rotor system are discussed. The comparative simulations show that the proposed model can provide a more reasonable approach for predicting the vibrations of the rigid rotor system. Moreover, the simulations give that the nonlinear contact forces in the support bearings can greatly affect the system vibrations.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90996346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2021-12-23DOI: 10.1177/14644193211056138
Yongjun Hou, G. Xiong, Pan Fang, Mingjun Du, Yuwen Wang
Nowadays, two exciters vibration system played an indispensable role in a majority of machinery and devices, such as vibratory feeder, vibrating screen, vibration conveyer, vibrating crusher, and so on. The stability of the system and the synchronous characteristics of two exciters are affected by material motion. However, those effects of material on two exciters vibration system were studied very little. Based on the special background, a mechanical model that two exciters vibration system considering material motion is proposed. Firstly, the system's dynamic equations are solved by using Lagrange principle and Newton's second law. Then, the motion stability of the system when material with different mass move on the vibrating body is analyzed by Poincar e ′ mapping and numerical simulation methods, and the motion forms of the material are also studied. Meanwhile, the frequency responses of the vibrating body are analyzed. Finally, the influence of material on the phase difference of the two exciters is revealed. It can be concluded that with the mass ratio of the material to the vibrating body increasing, the system's motion evolves from stable periodic motion to chaotic state, the synchronization ability of two exciters decline, and the unpredictability of abrupt change about the phase difference increases. Further, the uncertainties of both the abrupt change of phase difference and the collision location affect each other and eventually lead to the instability of the system.
{"title":"Stability and synchronous characteristics of a two exciters vibration system considering material motion","authors":"Yongjun Hou, G. Xiong, Pan Fang, Mingjun Du, Yuwen Wang","doi":"10.1177/14644193211056138","DOIUrl":"https://doi.org/10.1177/14644193211056138","url":null,"abstract":"Nowadays, two exciters vibration system played an indispensable role in a majority of machinery and devices, such as vibratory feeder, vibrating screen, vibration conveyer, vibrating crusher, and so on. The stability of the system and the synchronous characteristics of two exciters are affected by material motion. However, those effects of material on two exciters vibration system were studied very little. Based on the special background, a mechanical model that two exciters vibration system considering material motion is proposed. Firstly, the system's dynamic equations are solved by using Lagrange principle and Newton's second law. Then, the motion stability of the system when material with different mass move on the vibrating body is analyzed by Poincar e ′ mapping and numerical simulation methods, and the motion forms of the material are also studied. Meanwhile, the frequency responses of the vibrating body are analyzed. Finally, the influence of material on the phase difference of the two exciters is revealed. It can be concluded that with the mass ratio of the material to the vibrating body increasing, the system's motion evolves from stable periodic motion to chaotic state, the synchronization ability of two exciters decline, and the unpredictability of abrupt change about the phase difference increases. Further, the uncertainties of both the abrupt change of phase difference and the collision location affect each other and eventually lead to the instability of the system.","PeriodicalId":54565,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part K-Journal of Multi-Body Dynamics","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72764445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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