Pub Date : 2024-02-07DOI: 10.1177/14644193241229558
Ali Keymasi‐Khalaji, Iman Saadat
In this article, a novel control algorithm called the combined backstepping and feedback linearisation method, along with an uncertainty estimator, is presented for quadrotors. The objective is to develop a robust control algorithm capable of handling various flight conditions, compensating for uncertainties and disturbances, and effectively controlling high-speed manoeuvres. To accomplish this, the quadrotor dynamics model is first derived using the Newton–Euler method. Subsequently, a backstepping control algorithm is designed for the quadrotor's internal control layer, followed by the application of the feedback linearisation method to the external control layer. An estimator is also designed to mitigate the effects of disturbances and uncertainties. A comparison is made between the proposed combined backstepping and feedback linearisation algorithm and the backstepping method, revealing that the combined backstepping and feedback linearisation algorithm outperforms the backstepping method across different aspects. Notably, the combined backstepping and feedback linearisation algorithm achieves faster trajectory tracking and demonstrates fewer steady-state errors. Additionally, the integration of the uncertainty estimator into the combined backstepping and feedback linearisation algorithm effectively mitigates the detrimental effects of disturbances and uncertainties. Comparative results for tracking control are presented to evaluate the performance of the proposed algorithm across various scenarios and case studies.
{"title":"Quadrotor control in complex manoeuvres using a hybrid backstepping and feedback linearisation control strategy","authors":"Ali Keymasi‐Khalaji, Iman Saadat","doi":"10.1177/14644193241229558","DOIUrl":"https://doi.org/10.1177/14644193241229558","url":null,"abstract":"In this article, a novel control algorithm called the combined backstepping and feedback linearisation method, along with an uncertainty estimator, is presented for quadrotors. The objective is to develop a robust control algorithm capable of handling various flight conditions, compensating for uncertainties and disturbances, and effectively controlling high-speed manoeuvres. To accomplish this, the quadrotor dynamics model is first derived using the Newton–Euler method. Subsequently, a backstepping control algorithm is designed for the quadrotor's internal control layer, followed by the application of the feedback linearisation method to the external control layer. An estimator is also designed to mitigate the effects of disturbances and uncertainties. A comparison is made between the proposed combined backstepping and feedback linearisation algorithm and the backstepping method, revealing that the combined backstepping and feedback linearisation algorithm outperforms the backstepping method across different aspects. Notably, the combined backstepping and feedback linearisation algorithm achieves faster trajectory tracking and demonstrates fewer steady-state errors. Additionally, the integration of the uncertainty estimator into the combined backstepping and feedback linearisation algorithm effectively mitigates the detrimental effects of disturbances and uncertainties. Comparative results for tracking control are presented to evaluate the performance of the proposed algorithm across various scenarios and case studies.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"47 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139796873","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 : 2024-02-07DOI: 10.1177/14644193241229558
Ali Keymasi‐Khalaji, Iman Saadat
In this article, a novel control algorithm called the combined backstepping and feedback linearisation method, along with an uncertainty estimator, is presented for quadrotors. The objective is to develop a robust control algorithm capable of handling various flight conditions, compensating for uncertainties and disturbances, and effectively controlling high-speed manoeuvres. To accomplish this, the quadrotor dynamics model is first derived using the Newton–Euler method. Subsequently, a backstepping control algorithm is designed for the quadrotor's internal control layer, followed by the application of the feedback linearisation method to the external control layer. An estimator is also designed to mitigate the effects of disturbances and uncertainties. A comparison is made between the proposed combined backstepping and feedback linearisation algorithm and the backstepping method, revealing that the combined backstepping and feedback linearisation algorithm outperforms the backstepping method across different aspects. Notably, the combined backstepping and feedback linearisation algorithm achieves faster trajectory tracking and demonstrates fewer steady-state errors. Additionally, the integration of the uncertainty estimator into the combined backstepping and feedback linearisation algorithm effectively mitigates the detrimental effects of disturbances and uncertainties. Comparative results for tracking control are presented to evaluate the performance of the proposed algorithm across various scenarios and case studies.
{"title":"Quadrotor control in complex manoeuvres using a hybrid backstepping and feedback linearisation control strategy","authors":"Ali Keymasi‐Khalaji, Iman Saadat","doi":"10.1177/14644193241229558","DOIUrl":"https://doi.org/10.1177/14644193241229558","url":null,"abstract":"In this article, a novel control algorithm called the combined backstepping and feedback linearisation method, along with an uncertainty estimator, is presented for quadrotors. The objective is to develop a robust control algorithm capable of handling various flight conditions, compensating for uncertainties and disturbances, and effectively controlling high-speed manoeuvres. To accomplish this, the quadrotor dynamics model is first derived using the Newton–Euler method. Subsequently, a backstepping control algorithm is designed for the quadrotor's internal control layer, followed by the application of the feedback linearisation method to the external control layer. An estimator is also designed to mitigate the effects of disturbances and uncertainties. A comparison is made between the proposed combined backstepping and feedback linearisation algorithm and the backstepping method, revealing that the combined backstepping and feedback linearisation algorithm outperforms the backstepping method across different aspects. Notably, the combined backstepping and feedback linearisation algorithm achieves faster trajectory tracking and demonstrates fewer steady-state errors. Additionally, the integration of the uncertainty estimator into the combined backstepping and feedback linearisation algorithm effectively mitigates the detrimental effects of disturbances and uncertainties. Comparative results for tracking control are presented to evaluate the performance of the proposed algorithm across various scenarios and case studies.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"73 1-2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139856658","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 : 2024-02-01DOI: 10.1177/14644193241227352
Yun Wang, Wei Yang, Xiaolin Tang
In this paper, the main research is to investigate the effects of mechanical, friction, temperature, and tooth wear on the dynamic performance of a double-helical planetary gear transmission system. To achieve this, a new lumped parameters model is presented, which combines dynamics and lubrication. The model allows for the study of excitation effects and considers various parameters such as material, lubricating oil, and working conditions. By proposing a multi-source excitation calculation method, the paper provides a novel approach that has not been reported in the existing literature. Additionally, the paper establishes a tooth wear model and a lubrication model for the double-helical gear pair. It shows that under constant torque, the displacement and acceleration amplitudes of the system initially decrease and then increase with increasing input speed. Under constant speed, the displacement and acceleration amplitudes increase with increasing torque. Amplitudes decrease during running-in wear, increase in stable wear, and rapidly increase in severe wear. Boundary lubrication minimizes vibration, while elastohydrodynamic lubrication maximizes it.
{"title":"Research on the dynamic performance of double-helical planetary gear transmission under friction and wear","authors":"Yun Wang, Wei Yang, Xiaolin Tang","doi":"10.1177/14644193241227352","DOIUrl":"https://doi.org/10.1177/14644193241227352","url":null,"abstract":"In this paper, the main research is to investigate the effects of mechanical, friction, temperature, and tooth wear on the dynamic performance of a double-helical planetary gear transmission system. To achieve this, a new lumped parameters model is presented, which combines dynamics and lubrication. The model allows for the study of excitation effects and considers various parameters such as material, lubricating oil, and working conditions. By proposing a multi-source excitation calculation method, the paper provides a novel approach that has not been reported in the existing literature. Additionally, the paper establishes a tooth wear model and a lubrication model for the double-helical gear pair. It shows that under constant torque, the displacement and acceleration amplitudes of the system initially decrease and then increase with increasing input speed. Under constant speed, the displacement and acceleration amplitudes increase with increasing torque. Amplitudes decrease during running-in wear, increase in stable wear, and rapidly increase in severe wear. Boundary lubrication minimizes vibration, while elastohydrodynamic lubrication maximizes it.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"6 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139881031","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 : 2024-02-01DOI: 10.1177/14644193241227352
Yun Wang, Wei Yang, Xiaolin Tang
In this paper, the main research is to investigate the effects of mechanical, friction, temperature, and tooth wear on the dynamic performance of a double-helical planetary gear transmission system. To achieve this, a new lumped parameters model is presented, which combines dynamics and lubrication. The model allows for the study of excitation effects and considers various parameters such as material, lubricating oil, and working conditions. By proposing a multi-source excitation calculation method, the paper provides a novel approach that has not been reported in the existing literature. Additionally, the paper establishes a tooth wear model and a lubrication model for the double-helical gear pair. It shows that under constant torque, the displacement and acceleration amplitudes of the system initially decrease and then increase with increasing input speed. Under constant speed, the displacement and acceleration amplitudes increase with increasing torque. Amplitudes decrease during running-in wear, increase in stable wear, and rapidly increase in severe wear. Boundary lubrication minimizes vibration, while elastohydrodynamic lubrication maximizes it.
{"title":"Research on the dynamic performance of double-helical planetary gear transmission under friction and wear","authors":"Yun Wang, Wei Yang, Xiaolin Tang","doi":"10.1177/14644193241227352","DOIUrl":"https://doi.org/10.1177/14644193241227352","url":null,"abstract":"In this paper, the main research is to investigate the effects of mechanical, friction, temperature, and tooth wear on the dynamic performance of a double-helical planetary gear transmission system. To achieve this, a new lumped parameters model is presented, which combines dynamics and lubrication. The model allows for the study of excitation effects and considers various parameters such as material, lubricating oil, and working conditions. By proposing a multi-source excitation calculation method, the paper provides a novel approach that has not been reported in the existing literature. Additionally, the paper establishes a tooth wear model and a lubrication model for the double-helical gear pair. It shows that under constant torque, the displacement and acceleration amplitudes of the system initially decrease and then increase with increasing input speed. Under constant speed, the displacement and acceleration amplitudes increase with increasing torque. Amplitudes decrease during running-in wear, increase in stable wear, and rapidly increase in severe wear. Boundary lubrication minimizes vibration, while elastohydrodynamic lubrication maximizes it.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"46 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139820692","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}
Constrained by the unique operational conditions and the swinging motion of the payload, offshore cranes exhibit low lifting efficiency and positioning accuracy during operation. In this paper, magnetorheological (MR) technology is applied in the realm of payload anti-swing and positioning of offshore cranes for the first time. The anti-swing system adopts a parallel mechanical configuration design, offering a simple structure that does not encroach upon the crane's working space and exhibits high levels of robustness. Based on the principle of robotics, the kinematic and dynamic model of anti-swing system is derived. Co-simulation analysis is conducted to assess the swing response of the crane's payload throughout the lifting and transfer process amidst irregular ocean waves. The findings demonstrate that the MR anti-swing system effectively mitigates payload swing, achieving an anti-swing effect of over 80%. With a similar anti-swing effect, the MR anti-swing system with time-varying current reduces energy consumption by 54% compared to the system with fixed current. Subsequently, experimental results from the physical prototype reveal that the anti-swing system can suppress payload swing by over 80% during cargo transfer processes. This underscores the capability of the MR anti-swing system to enhance payload transfer efficiency and positioning accuracy.
{"title":"A novel magnetorheological anti-swing system for offshore crane: System modeling and controller design","authors":"Chenxu Deng, Yunlong Li, Guangdong Han, Shenghai Wang, Haiquan Chen, Yu-qing Sun","doi":"10.1177/14644193231219390","DOIUrl":"https://doi.org/10.1177/14644193231219390","url":null,"abstract":"Constrained by the unique operational conditions and the swinging motion of the payload, offshore cranes exhibit low lifting efficiency and positioning accuracy during operation. In this paper, magnetorheological (MR) technology is applied in the realm of payload anti-swing and positioning of offshore cranes for the first time. The anti-swing system adopts a parallel mechanical configuration design, offering a simple structure that does not encroach upon the crane's working space and exhibits high levels of robustness. Based on the principle of robotics, the kinematic and dynamic model of anti-swing system is derived. Co-simulation analysis is conducted to assess the swing response of the crane's payload throughout the lifting and transfer process amidst irregular ocean waves. The findings demonstrate that the MR anti-swing system effectively mitigates payload swing, achieving an anti-swing effect of over 80%. With a similar anti-swing effect, the MR anti-swing system with time-varying current reduces energy consumption by 54% compared to the system with fixed current. Subsequently, experimental results from the physical prototype reveal that the anti-swing system can suppress payload swing by over 80% during cargo transfer processes. This underscores the capability of the MR anti-swing system to enhance payload transfer efficiency and positioning accuracy.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139159549","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 : 2023-12-17DOI: 10.1177/14644193231220523
Wei Li, XiaoFeng Li, Ziyuan Li
Due to the advantages of stable helical gear transmission, it is widely used in industry, agriculture, and national defense. Shaft misalignment has a great influence on the vibration, bearing capacity, and life of gear transmission. Based on the idler wheel drive system as the research object, according to the principle of gear meshing, the helical gear time-varying contact wire length model was deduced. The dynamic model of the gear transmission system with faults is established considering the faults of the idler's center distance error and angle error, and the influence law of idler misalignment fault on the vibration of the idler transmission system is revealed. On this basis, the finite element model under angle error is established to analyze the contact stress of the tooth surface under different faults and reveal the contact stress distribution law of the tooth surface. The results show that the misalignment fault will change the length of the helical gear contact line. When the gear shaft misaligns, it will increase the axial force of the gear and increase the axial vibration of the gear. Moreover, the angle error will cause uneven load distribution on the tooth surface of the helical gear, which will reduce the contact area of the gear and increase the contact stress. The phenomenon of off-load of gear accelerates the wear of the gear tooth surface and shortens the life of the gear. The study of idler misalignment fault is of great significance for prolonging the life of gear and providing the basis for gear fault diagnosis.
{"title":"Influence of idler misalignment fault on contact and dynamic characteristics of helical gear","authors":"Wei Li, XiaoFeng Li, Ziyuan Li","doi":"10.1177/14644193231220523","DOIUrl":"https://doi.org/10.1177/14644193231220523","url":null,"abstract":"Due to the advantages of stable helical gear transmission, it is widely used in industry, agriculture, and national defense. Shaft misalignment has a great influence on the vibration, bearing capacity, and life of gear transmission. Based on the idler wheel drive system as the research object, according to the principle of gear meshing, the helical gear time-varying contact wire length model was deduced. The dynamic model of the gear transmission system with faults is established considering the faults of the idler's center distance error and angle error, and the influence law of idler misalignment fault on the vibration of the idler transmission system is revealed. On this basis, the finite element model under angle error is established to analyze the contact stress of the tooth surface under different faults and reveal the contact stress distribution law of the tooth surface. The results show that the misalignment fault will change the length of the helical gear contact line. When the gear shaft misaligns, it will increase the axial force of the gear and increase the axial vibration of the gear. Moreover, the angle error will cause uneven load distribution on the tooth surface of the helical gear, which will reduce the contact area of the gear and increase the contact stress. The phenomenon of off-load of gear accelerates the wear of the gear tooth surface and shortens the life of the gear. The study of idler misalignment fault is of great significance for prolonging the life of gear and providing the basis for gear fault diagnosis.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"681 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139176767","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}
Along with the rotating machinery advances toward high speeds, the significance of the excitation force of the seal fluid in the rotor system is growing, which can cause serious accidents. Most of the previous research on rotors in rotating machinery has predominantly focused on the effects of misalignment in couplings. In this article, a novel model is proposed, introducing an analytical approach that combines both internal friction in couplings and loosening support faults. Additionally, an analysis and discussion of the vibration characteristics of the rotating system under the influence of internal friction are presented. This method allows for a more comprehensive assessment of the performance of rotors in engineering applications. Assuming that the left support of the rotor is loose, this model focused on how various factors such as rotor speeds, eccentricity, seal disc mass, and left-end support mass affect the labyrinth seal rotor system's dynamic characteristics. Based on the findings, The emergence of internal friction forces advances the chaos of the rotor. It seems that as the rotating speed increases, there will be a small frequency range, resulting in fluid oscillation, and the system stability will be reduced at this time. The improvement in the seal disc's quality has minimal impact on the stability of the left journal, but it will reduce the stability of the seal disc. The increase in the mass of the left end support will increase the stability of the movement at the left journal and reduce the stability of the movement at the seal disc.
{"title":"Dynamic characteristics analysis of a rotor system with loose support considering internal friction in couplings","authors":"Yuan Wei, Jia Guo, Bowen Ma, Fanyi Xu, Kai-Uwe Schröder","doi":"10.1177/14644193231219181","DOIUrl":"https://doi.org/10.1177/14644193231219181","url":null,"abstract":"Along with the rotating machinery advances toward high speeds, the significance of the excitation force of the seal fluid in the rotor system is growing, which can cause serious accidents. Most of the previous research on rotors in rotating machinery has predominantly focused on the effects of misalignment in couplings. In this article, a novel model is proposed, introducing an analytical approach that combines both internal friction in couplings and loosening support faults. Additionally, an analysis and discussion of the vibration characteristics of the rotating system under the influence of internal friction are presented. This method allows for a more comprehensive assessment of the performance of rotors in engineering applications. Assuming that the left support of the rotor is loose, this model focused on how various factors such as rotor speeds, eccentricity, seal disc mass, and left-end support mass affect the labyrinth seal rotor system's dynamic characteristics. Based on the findings, The emergence of internal friction forces advances the chaos of the rotor. It seems that as the rotating speed increases, there will be a small frequency range, resulting in fluid oscillation, and the system stability will be reduced at this time. The improvement in the seal disc's quality has minimal impact on the stability of the left journal, but it will reduce the stability of the seal disc. The increase in the mass of the left end support will increase the stability of the movement at the left journal and reduce the stability of the movement at the seal disc.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"13 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139183023","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 : 2023-11-27DOI: 10.1177/14644193231197262
A. Shabana
This article discusses a new approach for predicting and quantifying mechanically induced temperature oscillations in the coupled thermo-elasticity analysis of articulated mechanical systems (AMS). In this approach, the constrained equations of motion are solved simultaneously with discrete temperature equations obtained by converting heat partial-differential equation to a set of first-order ordinary differential equations. Dependence of the temperature gradients and their spatial derivatives on the position gradients, spinning motion, and curvatures is discussed. The approach captures dependence of the temperature-oscillation frequencies on the mechanical-displacement frequencies. The temperature field can be selected to ensure continuity of the temperature gradients at the nodal points. To generalize the AMS coupled thermo-elasticity formulation and capture the effect of the boundary and motion constraints (BMC) on the thermal expansion, the proposed method is based on integrating thermodynamics and Lagrange-D’Alembert principles. The absolute nodal coordinate formulation (ANCF) is used to describe continuum displacement and obtain accurate description of the reference-configuration geometry and change of this geometry due to deformations. A thermal-analysis large-displacement formulation is used to allow converting heat energy to kinetic energy, ensuring stress-free thermal expansion in case of unconstrained uniform thermal expansion. Cholesky heat coordinates are used to define an identity coefficient matrix for the efficient solution of the discretized heat equations. The approach presented is applicable to the two different forms of the heat equation used in the literature; one form is explicit function of the stresses while the other form does not depend explicitly on the stresses. Because of the need for using ANCF finite elements to achieve a higher degree of continuity in the coupled thermomechanical approach introduced in this article, the concept of the ANCF mesh topology is discussed.
{"title":"Mechanically induced temperature oscillations in the coupled thermo-elasticity analysis of articulated dynamical systems","authors":"A. Shabana","doi":"10.1177/14644193231197262","DOIUrl":"https://doi.org/10.1177/14644193231197262","url":null,"abstract":"This article discusses a new approach for predicting and quantifying mechanically induced temperature oscillations in the coupled thermo-elasticity analysis of articulated mechanical systems (AMS). In this approach, the constrained equations of motion are solved simultaneously with discrete temperature equations obtained by converting heat partial-differential equation to a set of first-order ordinary differential equations. Dependence of the temperature gradients and their spatial derivatives on the position gradients, spinning motion, and curvatures is discussed. The approach captures dependence of the temperature-oscillation frequencies on the mechanical-displacement frequencies. The temperature field can be selected to ensure continuity of the temperature gradients at the nodal points. To generalize the AMS coupled thermo-elasticity formulation and capture the effect of the boundary and motion constraints (BMC) on the thermal expansion, the proposed method is based on integrating thermodynamics and Lagrange-D’Alembert principles. The absolute nodal coordinate formulation (ANCF) is used to describe continuum displacement and obtain accurate description of the reference-configuration geometry and change of this geometry due to deformations. A thermal-analysis large-displacement formulation is used to allow converting heat energy to kinetic energy, ensuring stress-free thermal expansion in case of unconstrained uniform thermal expansion. Cholesky heat coordinates are used to define an identity coefficient matrix for the efficient solution of the discretized heat equations. The approach presented is applicable to the two different forms of the heat equation used in the literature; one form is explicit function of the stresses while the other form does not depend explicitly on the stresses. Because of the need for using ANCF finite elements to achieve a higher degree of continuity in the coupled thermomechanical approach introduced in this article, the concept of the ANCF mesh topology is discussed.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"276 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139228697","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 : 2023-11-19DOI: 10.1177/14644193231211109
ZhuJin Wu, Hesheng Tang, Pingting Ying, Yan Ren, Anil Kumar
Healthy roller bearings are essential for the safe performance of axial piston pumps. A dynamic failure model of a rotor–bearing-casing system was developed to investigate the effect of bearing damage on the vibration characteristics and stability. This model considers the effect of large-gap circulation on a wet rotor system model, which is closely related to the stirring conditions during actual operation of axial piston pumps. The stator and rotor of the pump were modelled using the centralised parameter technique and finite element method, which were combined to develop the rotor–bearing-casing model. Vibration and stability analyses were performed for the system model with bearing failure, considering the gap annular flow and hydraulic excitation force. The effects of the mass eccentricity, rotational speed, and discharge pressure on the vibration characteristics and stability were analysed under different types of bearing failures. Furthermore, the vibration behaviour of the rotor–bearing-casing system with a bearing fault was measured to validate the established dynamic model. The results indicated that the rotational speed and rotor eccentricity affected the churning and unbalanced effects of the rotor. With an increase in the rotor eccentricity, the rotor first transitioned from nonlinear motion to one-period motion and subsequently to periodic motion. The rotor energy reduction and steady state of the rotor–bearing-casing system were induced by the rotor churning action. As the annular gap decreased, churning losses increased, resulting in a more stable rotor motion.
{"title":"Vibration and stability analyses of rotor–bearing-casing system in an axial piston pump subjected to bearing faults","authors":"ZhuJin Wu, Hesheng Tang, Pingting Ying, Yan Ren, Anil Kumar","doi":"10.1177/14644193231211109","DOIUrl":"https://doi.org/10.1177/14644193231211109","url":null,"abstract":"Healthy roller bearings are essential for the safe performance of axial piston pumps. A dynamic failure model of a rotor–bearing-casing system was developed to investigate the effect of bearing damage on the vibration characteristics and stability. This model considers the effect of large-gap circulation on a wet rotor system model, which is closely related to the stirring conditions during actual operation of axial piston pumps. The stator and rotor of the pump were modelled using the centralised parameter technique and finite element method, which were combined to develop the rotor–bearing-casing model. Vibration and stability analyses were performed for the system model with bearing failure, considering the gap annular flow and hydraulic excitation force. The effects of the mass eccentricity, rotational speed, and discharge pressure on the vibration characteristics and stability were analysed under different types of bearing failures. Furthermore, the vibration behaviour of the rotor–bearing-casing system with a bearing fault was measured to validate the established dynamic model. The results indicated that the rotational speed and rotor eccentricity affected the churning and unbalanced effects of the rotor. With an increase in the rotor eccentricity, the rotor first transitioned from nonlinear motion to one-period motion and subsequently to periodic motion. The rotor energy reduction and steady state of the rotor–bearing-casing system were induced by the rotor churning action. As the annular gap decreased, churning losses increased, resulting in a more stable rotor motion.","PeriodicalId":510687,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics","volume":"1 1","pages":"681 - 709"},"PeriodicalIF":0.0,"publicationDate":"2023-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139260033","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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