A finite element model is created using OpenSees software to perform a time history analysis in order to analyze the seismic response law of a skew bridge and the damage volume of its key components, using a typical 3×20 m skew continuous girder bridge as an example. The seismic response of the skew continuous girder bridge under various factors such as the size of the abutment expansion joint, shear key gap, and shear key strength is studied then the damage rate is assessed for the bearing, shear key, and pier. The research results show that under the action of earthquake ground motion with 0.3 g PGA, the seismic force transmitted to the pier is small, and the pier is elastic owing to the sliding of the bearing, but the damage degree of the shear key is larger than that of the bearing and pier. The impact increases the rotation effect of the main beam in the direction of off acute angle, resulting in a greater damage to the shear key at the acute angle than that at the obtuse angle. The damage of bearing and shear key increases and then decreases with the increasing of expansion joint, and the larger the skew angle is, the smaller the expansion joint will be corresponding to the maximum displacement of bearing and shear key. With the increase of the shear key gap, the deformation limitation effect of the shear key on the main beam decreases significantly, resulting in a linear increase in the bearing slip, which increases the risk of the main beam subsidence. With the increase of the shear key strength, the bearing and shear key damage decreases greatly at first, and then increases slightly. However, the pier damage increases obviously. In an area with a high risk of earthquake, it is recommended that the shear key can be a “fuse element”. For any oblique angle, the shear key gap can be reduced to 2 cm, and the shear key strength can be increased to 125 % or 150 %. When the skew angle is between 30 and 60, the expansion joint size can be increased to 12 cm or 16 cm.
利用OpenSees软件建立有限元模型进行时程分析，以典型的3×20 m斜度连续梁桥为例，分析斜度桥梁的地震反应规律及关键构件的损伤体积。研究了斜交连续梁桥在桥台伸缩缝尺寸、剪力键间距和剪力键强度等因素下的地震反应，并对支座、剪力键和桥墩的损伤率进行了评估。研究结果表明:在0.3 g PGA的地震地震动作用下，传递给桥墩的地震力较小，桥墩由于支座的滑动而具有弹性，但剪力键的破坏程度大于支座和桥墩的破坏程度。冲击增加了主梁在非锐角方向上的旋转效应，导致锐角处剪切键的损伤大于钝角处。随着伸缩缝的增大，轴承和剪切键的损伤先增大后减小，且斜倾角越大，伸缩缝对应的轴承和剪切键最大位移越小。随着剪力键间隙的增大，剪力键对主梁的变形限制作用显著减弱，导致支座滑移呈线性增加，增加了主梁沉降的风险。随着抗剪键强度的增大，轴承和抗剪键损伤先大幅减小，后略有增大。但桥墩损伤明显增大。在地震风险高的地区，建议将剪切键作为“保险丝元件”。对于任意斜角，可将剪切键间隙减小至2 cm，可将剪切键强度提高至125%或150%。当倾斜角度在30 ~ 60之间时，可将伸缩缝尺寸增加到12cm或16cm。
{"title":"Determination of reasonable parameters for skew bridge under different skew angles","authors":"Weitao Yin, Kehai Wang, Weizuo Guo","doi":"10.21595/jve.2022.22907","DOIUrl":"https://doi.org/10.21595/jve.2022.22907","url":null,"abstract":"A finite element model is created using OpenSees software to perform a time history analysis in order to analyze the seismic response law of a skew bridge and the damage volume of its key components, using a typical 3×20 m skew continuous girder bridge as an example. The seismic response of the skew continuous girder bridge under various factors such as the size of the abutment expansion joint, shear key gap, and shear key strength is studied then the damage rate is assessed for the bearing, shear key, and pier. The research results show that under the action of earthquake ground motion with 0.3 g PGA, the seismic force transmitted to the pier is small, and the pier is elastic owing to the sliding of the bearing, but the damage degree of the shear key is larger than that of the bearing and pier. The impact increases the rotation effect of the main beam in the direction of off acute angle, resulting in a greater damage to the shear key at the acute angle than that at the obtuse angle. The damage of bearing and shear key increases and then decreases with the increasing of expansion joint, and the larger the skew angle is, the smaller the expansion joint will be corresponding to the maximum displacement of bearing and shear key. With the increase of the shear key gap, the deformation limitation effect of the shear key on the main beam decreases significantly, resulting in a linear increase in the bearing slip, which increases the risk of the main beam subsidence. With the increase of the shear key strength, the bearing and shear key damage decreases greatly at first, and then increases slightly. However, the pier damage increases obviously. In an area with a high risk of earthquake, it is recommended that the shear key can be a “fuse element”. For any oblique angle, the shear key gap can be reduced to 2 cm, and the shear key strength can be increased to 125 % or 150 %. When the skew angle is between 30 and 60, the expansion joint size can be increased to 12 cm or 16 cm.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48151097","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 research aims to enhance the seismic safety of the segmental assembled round end hollow pier (SAREHP) of high-speed railway in high intensity seismic regions and ensure the repairability of the pier after earthquake. A low yield point steel connection buckle (LYPSCB), which is easy to be installed and to be replaced after earthquake damage, was proposed as a new seismic absorption measure for the pier, and the seismic absorption effect of the LYPSCB was deeply studied. Firstly, the nonlinear numerical model of the SAREHP with energy dissipation bar (SAREHP-EDB) was established according to the pseudo-static test results of the pier completed. Based on the numerical model of the SAREHP-EDB, the SAREHP with the LYPSCB (SAREHP-LYPSCB) was established and corrected. Subsequently, the influence of the LYPSCB on the hysteretic behavior of the SAREHP was studied, and the hysteretic behavior of the SAREHP-LYPSCB was comprehensively compared with a reference to the SAREHP-EDB. Furthermore, considering the far-field seismic wave and the near-field seismic wave with or without pulse, the seismic absorption effect of the LYPSCB was revealed through dynamic time history analysis method. The research results indicated that, by increasing the section contribution rate of the LYPSCB, the horizontal resistance, loading and unloading stiffness as well as energy dissipation capacity of the SAREHP-LYPSCB are significantly improved. However, the residual displacement of the pier is also indirectly increased. Therefore, it is suggested that the section contribution rate of the LYPSCB is controlled and designed in combination with the seismic target displacement and self-centering capacity demand of pier. The hysteretic behavior of the SAREHP-LYPSCB is better than that of the SAREHP-EDB, which indicated that the LYPSCB possesses better seismic absorption effect. Note that the seismic absorption effect of the LYPSCB is more obvious in resisting strong earthquake, in which the seismic absorption rate can reach 80 %. The near-field pulse seismic wave has the greatest impact on the seismic response of the SAREHP-LYPSCB compared with other types of seismic wave, which should be paid special attention.
{"title":"Research on seismic absorption of high-speed railway segmental assembled round-end hollow pier with low yield point steel connection buckle","authors":"Hao Li, Yuanqing Xu, Hongjie Zhang, Shiyun Qi","doi":"10.21595/jve.2022.22859","DOIUrl":"https://doi.org/10.21595/jve.2022.22859","url":null,"abstract":"The research aims to enhance the seismic safety of the segmental assembled round end hollow pier (SAREHP) of high-speed railway in high intensity seismic regions and ensure the repairability of the pier after earthquake. A low yield point steel connection buckle (LYPSCB), which is easy to be installed and to be replaced after earthquake damage, was proposed as a new seismic absorption measure for the pier, and the seismic absorption effect of the LYPSCB was deeply studied. Firstly, the nonlinear numerical model of the SAREHP with energy dissipation bar (SAREHP-EDB) was established according to the pseudo-static test results of the pier completed. Based on the numerical model of the SAREHP-EDB, the SAREHP with the LYPSCB (SAREHP-LYPSCB) was established and corrected. Subsequently, the influence of the LYPSCB on the hysteretic behavior of the SAREHP was studied, and the hysteretic behavior of the SAREHP-LYPSCB was comprehensively compared with a reference to the SAREHP-EDB. Furthermore, considering the far-field seismic wave and the near-field seismic wave with or without pulse, the seismic absorption effect of the LYPSCB was revealed through dynamic time history analysis method. The research results indicated that, by increasing the section contribution rate of the LYPSCB, the horizontal resistance, loading and unloading stiffness as well as energy dissipation capacity of the SAREHP-LYPSCB are significantly improved. However, the residual displacement of the pier is also indirectly increased. Therefore, it is suggested that the section contribution rate of the LYPSCB is controlled and designed in combination with the seismic target displacement and self-centering capacity demand of pier. The hysteretic behavior of the SAREHP-LYPSCB is better than that of the SAREHP-EDB, which indicated that the LYPSCB possesses better seismic absorption effect. Note that the seismic absorption effect of the LYPSCB is more obvious in resisting strong earthquake, in which the seismic absorption rate can reach 80 %. The near-field pulse seismic wave has the greatest impact on the seismic response of the SAREHP-LYPSCB compared with other types of seismic wave, which should be paid special attention.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45511531","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}
Changshun Hao, Y. Ni, Baodong Liu, B. Han, Hui Jiang
To comprehensively consider and study the seismic performance of the self-center mortise-tenon segmental pier, its vulnerability under earthquake is evaluated. The reliability of the model is verified by comparing the cyclic pseudo-static test results with the finite element models. The model is used as the basis for vulnerability analysis. Taking the maximum displacement of the pier top as a damage index. Different damage states are described. The damage index limits μcy1, μcy, μc2, and μcmax of different damage levels are determined. The time history analysis of cast-in-place pier and mortise-tenon segmental piers under different earthquake actions is carried out by using finite element software. The probabilistic seismic demand model is established through IDA curves. And the seismic vulnerability analysis is carried out. The influence of various parameters on the seismic vulnerability of mortise-tenon segmental pier is studied by changing the longitudinal reinforcement ratio, axial compression ratio, and aspect ratio. The results show that the seismic vulnerability of the two types of piers designed according to the principle of equivalence is similar under different damage states. It can be considered that it has better seismic performance. The longitudinal reinforcement ratio, axial compression ratio, and aspect ratio have a great impact on the vulnerability of piers.
{"title":"Seismic fragility analysis of self-centering segmental piers with mortise-tenon shear keys","authors":"Changshun Hao, Y. Ni, Baodong Liu, B. Han, Hui Jiang","doi":"10.21595/jve.2022.23003","DOIUrl":"https://doi.org/10.21595/jve.2022.23003","url":null,"abstract":"To comprehensively consider and study the seismic performance of the self-center mortise-tenon segmental pier, its vulnerability under earthquake is evaluated. The reliability of the model is verified by comparing the cyclic pseudo-static test results with the finite element models. The model is used as the basis for vulnerability analysis. Taking the maximum displacement of the pier top as a damage index. Different damage states are described. The damage index limits μcy1, μcy, μc2, and μcmax of different damage levels are determined. The time history analysis of cast-in-place pier and mortise-tenon segmental piers under different earthquake actions is carried out by using finite element software. The probabilistic seismic demand model is established through IDA curves. And the seismic vulnerability analysis is carried out. The influence of various parameters on the seismic vulnerability of mortise-tenon segmental pier is studied by changing the longitudinal reinforcement ratio, axial compression ratio, and aspect ratio. The results show that the seismic vulnerability of the two types of piers designed according to the principle of equivalence is similar under different damage states. It can be considered that it has better seismic performance. The longitudinal reinforcement ratio, axial compression ratio, and aspect ratio have a great impact on the vulnerability of piers.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42499561","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 instantaneous dynamic contact state analysis is carried out to reveal the process of scuffing failure of the gear tooth pair. A stick-slip dynamic model of a two-gear set is proposed and the coupling effects of time-varying mesh stiffness, tooth separations, friction between the gear teeth surfaces, and potential stick-slip are considered. Dynamic analysis shows that stick contact is an important source of tooth scuffing failure. Additionally, stick contact dramatically increases the vibration amplitudes and causes chaos. Parametric studies show that heavy load and rough tooth surfaces increase the probability of sticking and increase the time of stick state over a single mesh period. This study provides a design guard for avoiding scuffing failure and improving the reliability of gear transmission.
{"title":"Dynamic analysis of gear pairs with the effects of stick-slip","authors":"Chao Xun, He Dai, Yunlong Wang","doi":"10.21595/jve.2023.22976","DOIUrl":"https://doi.org/10.21595/jve.2023.22976","url":null,"abstract":"The instantaneous dynamic contact state analysis is carried out to reveal the process of scuffing failure of the gear tooth pair. A stick-slip dynamic model of a two-gear set is proposed and the coupling effects of time-varying mesh stiffness, tooth separations, friction between the gear teeth surfaces, and potential stick-slip are considered. Dynamic analysis shows that stick contact is an important source of tooth scuffing failure. Additionally, stick contact dramatically increases the vibration amplitudes and causes chaos. Parametric studies show that heavy load and rough tooth surfaces increase the probability of sticking and increase the time of stick state over a single mesh period. This study provides a design guard for avoiding scuffing failure and improving the reliability of gear transmission.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135554585","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}
Aiming at the problem that five axis redundant industrial manipulator dynamic obstacle avoidance and trajectory planning algorithm does not consider the minimum difference of each joint of the manipulator, which leads to low success rate of obstacle avoidance planning, slow convergence speed of path cost and long time of obstacle avoidance planning, a simulation study on dynamic obstacle avoidance trajectory planning of five axis redundant industrial manipulator is proposed. According to the D-H rule, the coordinate system of each link joint of the five axis redundant industrial manipulator is established, and the forward and inverse kinematics of the five axis redundant industrial manipulator is analyzed. AABB's hierarchical bounding box tree algorithm is used to detect the collision of five axis redundant industrial manipulator. This paper uses harmony search algorithm to plan the obstacle avoidance path of five axis redundant industrial manipulator, determines the objective function and constraints of the optimization problem, sets algorithm parameters, initializes harmony memory, creates new harmony, updates harmony memory, checks and searches the target state, achieves the maximum number of iterations, and realizes the dynamic obstacle avoidance and trajectory planning of five axis redundant industrial manipulator. The experimental results show that the path cost of the proposed algorithm converges faster, and can effectively improve the success rate of obstacle avoidance planning and shorten the time of obstacle avoidance planning.
{"title":"Dynamic obstacle avoidance and trajectory planning of five-axis redundant industrial manipulator","authors":"Jian Ma","doi":"10.21595/jve.2022.22944","DOIUrl":"https://doi.org/10.21595/jve.2022.22944","url":null,"abstract":"Aiming at the problem that five axis redundant industrial manipulator dynamic obstacle avoidance and trajectory planning algorithm does not consider the minimum difference of each joint of the manipulator, which leads to low success rate of obstacle avoidance planning, slow convergence speed of path cost and long time of obstacle avoidance planning, a simulation study on dynamic obstacle avoidance trajectory planning of five axis redundant industrial manipulator is proposed. According to the D-H rule, the coordinate system of each link joint of the five axis redundant industrial manipulator is established, and the forward and inverse kinematics of the five axis redundant industrial manipulator is analyzed. AABB's hierarchical bounding box tree algorithm is used to detect the collision of five axis redundant industrial manipulator. This paper uses harmony search algorithm to plan the obstacle avoidance path of five axis redundant industrial manipulator, determines the objective function and constraints of the optimization problem, sets algorithm parameters, initializes harmony memory, creates new harmony, updates harmony memory, checks and searches the target state, achieves the maximum number of iterations, and realizes the dynamic obstacle avoidance and trajectory planning of five axis redundant industrial manipulator. The experimental results show that the path cost of the proposed algorithm converges faster, and can effectively improve the success rate of obstacle avoidance planning and shorten the time of obstacle avoidance planning.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135554577","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}
Considering that the scraper will produce longitudinal and torsional pendulum vibration when passing through the bending section, and have a great influence on the motion characteristics of the scraper conveyor, this paper studies the longitudinal and torsional pendulum coupling vibration characteristics of the scraper conveyor under the working condition of over-bending section for the first time. Firstly, the simplified model of torsional pendulum vibration of scraper chain system is established based on Voigt model and point-by-point tension method. Then, the change law of scraper group vibration and chain tension under the condition of scraper bending is studied. Thirdly, through the influence area and attenuation characteristics of torsional pendulum vibration, the thumbnail model of torsional pendulum vibration is constructed. Finally, the longitudinal and torsional pendulum coupling vibration dynamic model of the scraper chain system is constructed based on the torsional pendulum vibration abbreviation model, and the overall longitudinal and torsional pendulum vibration characteristics of the scraper conveyor are studied when the scraper is over the bending section. The conclusion of this paper provides a theoretical basis for better understanding the operation characteristics of scraper conveyor in coal mine.
{"title":"Analysis of longitudinal and torsional vibration of mining scraper conveyor under the over bending section working condition","authors":"C. Xie, Zhi-Xiang Liu, M. Xie","doi":"10.21595/jve.2022.22977","DOIUrl":"https://doi.org/10.21595/jve.2022.22977","url":null,"abstract":"Considering that the scraper will produce longitudinal and torsional pendulum vibration when passing through the bending section, and have a great influence on the motion characteristics of the scraper conveyor, this paper studies the longitudinal and torsional pendulum coupling vibration characteristics of the scraper conveyor under the working condition of over-bending section for the first time. Firstly, the simplified model of torsional pendulum vibration of scraper chain system is established based on Voigt model and point-by-point tension method. Then, the change law of scraper group vibration and chain tension under the condition of scraper bending is studied. Thirdly, through the influence area and attenuation characteristics of torsional pendulum vibration, the thumbnail model of torsional pendulum vibration is constructed. Finally, the longitudinal and torsional pendulum coupling vibration dynamic model of the scraper chain system is constructed based on the torsional pendulum vibration abbreviation model, and the overall longitudinal and torsional pendulum vibration characteristics of the scraper conveyor are studied when the scraper is over the bending section. The conclusion of this paper provides a theoretical basis for better understanding the operation characteristics of scraper conveyor in coal mine.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43961717","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 linear asymmetric damper’s effects on the ride comfort, safety, and handling control were investigated to get full understanding of the suspension system design processes of an inner-city bus. The dynamic responses were analyzed for both two cases of linear symmetric and linear asymmetric dampers using the quarter car model with two degrees of freedom (2 DOFs) subjected to random road profiles and single bump cases of triangular and sine-squared bumps. The obtained results show that the linear symmetric damper performs the same as that of the linear asymmetric one in terms of comprehensive performance when the vehicle is subjected to a random road profile. The ride comfort, the working space have been significantly improved in specific range of velocity in case of the linear asymmetric damper. However, in general, slightly better performance has been obtained in the linear symmetric damper case.
{"title":"An investigation of a bus’s ride comfort by using the quarter car model with linear asymmetric damper","authors":"D. Le, Huu Nhan Tran","doi":"10.21595/jve.2022.22811","DOIUrl":"https://doi.org/10.21595/jve.2022.22811","url":null,"abstract":"The linear asymmetric damper’s effects on the ride comfort, safety, and handling control were investigated to get full understanding of the suspension system design processes of an inner-city bus. The dynamic responses were analyzed for both two cases of linear symmetric and linear asymmetric dampers using the quarter car model with two degrees of freedom (2 DOFs) subjected to random road profiles and single bump cases of triangular and sine-squared bumps. The obtained results show that the linear symmetric damper performs the same as that of the linear asymmetric one in terms of comprehensive performance when the vehicle is subjected to a random road profile. The ride comfort, the working space have been significantly improved in specific range of velocity in case of the linear asymmetric damper. However, in general, slightly better performance has been obtained in the linear symmetric damper case.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46425938","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}
Automatic transmission system is the core part of vehicle transmission processing, which can improve driving safety. In order to improve the shift effect of automotive automatic mechanical transmission and narrow the gap between the vehicle speed and the expected speed, an automotive automatic mechanical transmission system based on torsional damping was designed in the experiment. On the basis of hardware composed of different modules and fuzzy control algorithm, the system realizes the software design of vehicle automatic mechanical transmission system. The experimental results show that when the system is applied in practice, the gear selection time of the vehicle is between 0.2 s-0.3 s, and the gear shift time is between 0.3 s-0.4 s. The gap between the vehicle speed and the expected speed, and between the vehicle speed and the expected speed is small. The practical application effect is good.
自动变速器系统是车辆变速器处理的核心部分，可以提高行车安全性。为了提高汽车机械自动变速器的换挡效果，缩小车速与期望速度之间的差距，实验设计了一种基于扭转阻尼的汽车机械自动变速器系统。基于不同模块组成的硬件和模糊控制算法，实现了汽车自动机械传动系统的软件设计。实验结果表明，该系统在实际应用中，车辆的选挡时间在0.2 s ~ 0.3 s之间，换挡时间在0.3 s ~ 0.4 s之间。车速与预期速度、车速与预期速度之间的差距较小。实际应用效果良好。
{"title":"Design of automotive mechanical automatic transmission system based on torsional vibration reduction","authors":"Zhuan You","doi":"10.21595/jve.2022.22947","DOIUrl":"https://doi.org/10.21595/jve.2022.22947","url":null,"abstract":"Automatic transmission system is the core part of vehicle transmission processing, which can improve driving safety. In order to improve the shift effect of automotive automatic mechanical transmission and narrow the gap between the vehicle speed and the expected speed, an automotive automatic mechanical transmission system based on torsional damping was designed in the experiment. On the basis of hardware composed of different modules and fuzzy control algorithm, the system realizes the software design of vehicle automatic mechanical transmission system. The experimental results show that when the system is applied in practice, the gear selection time of the vehicle is between 0.2 s-0.3 s, and the gear shift time is between 0.3 s-0.4 s. The gap between the vehicle speed and the expected speed, and between the vehicle speed and the expected speed is small. The practical application effect is good.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48907317","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 collision force of a heavy rail transit vehicle hitting a bridge pier is affected by many factors. In order to investigate the characteristics of the collision force when a heavy rail transit vehicle hits a bridge, the finite element software LS-DYNA is used to simulate the impact of a heavy rail transit vehicle on a bridge. The influence of the vehicle speed of heavy rail transit vehicles, the strength of bridge pier concrete, the spacing of pier stirrups, the ratio of pier stirrup reinforcement, and the eccentric distance between the vehicle and the bridge pier on the characteristics of the collision force. The simulation analysis results show that the total deformation frequency around the impact point of the bridge pier and the heavy rail transit vehicle decreases as the distance from the impact point increases, and the deformation frequency in the vicinity of the impact point is the largest. The speed of the heavy rail transit vehicle, the concrete strength of the bridge pier, the reinforcement ratio of the pier stirrup, the larger the eccentric distance between the vehicle and the bridge pier, and the smaller the spacing between the stirrups, the greater the collision force when the heavy rail transit vehicle hits the bridge pier.
{"title":"Numerical simulation of heavy rail transit vehicle collision and analysis of collision force characteristics","authors":"Wen Zhang, Chun Li","doi":"10.21595/jve.2022.22942","DOIUrl":"https://doi.org/10.21595/jve.2022.22942","url":null,"abstract":"The collision force of a heavy rail transit vehicle hitting a bridge pier is affected by many factors. In order to investigate the characteristics of the collision force when a heavy rail transit vehicle hits a bridge, the finite element software LS-DYNA is used to simulate the impact of a heavy rail transit vehicle on a bridge. The influence of the vehicle speed of heavy rail transit vehicles, the strength of bridge pier concrete, the spacing of pier stirrups, the ratio of pier stirrup reinforcement, and the eccentric distance between the vehicle and the bridge pier on the characteristics of the collision force. The simulation analysis results show that the total deformation frequency around the impact point of the bridge pier and the heavy rail transit vehicle decreases as the distance from the impact point increases, and the deformation frequency in the vicinity of the impact point is the largest. The speed of the heavy rail transit vehicle, the concrete strength of the bridge pier, the reinforcement ratio of the pier stirrup, the larger the eccentric distance between the vehicle and the bridge pier, and the smaller the spacing between the stirrups, the greater the collision force when the heavy rail transit vehicle hits the bridge pier.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43261677","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}
To clear the wear effect of friction pendulum bearings (FPBs) on the seismic performance of multiple long-span continuous girder bridges, the rapid sliding performance test of the FPBs was carried out to get the wear degree of the modified poly tetra fluoroethylene (PTFE) wear plates. Taking a 6×110 m long-span continuous girder bridge as the engineering background, the seismic response of the bridge with different wear degrees of the FPBs was analyzed. The results show that the modified PTFE wear plate of the FPBs was severely worn in the rapid sliding performance test, and the friction coefficient was first increased to 0.09 and then decreased to 0.016. When the maximum displacement was reached, the bearing collided with the limitation block. Moreover, the internal forces of the critical pier were increased, and the bottom of the piers entered plasticity due to the wear of the FPBs. Due to the change in the seismic performance of the bridge, it is suggested that the rapid sliding performance of FPBs should be tested to ensure the structure safety of the long-span continuous girder bridge in rare earthquakes.
{"title":"Effects of friction pendulum bearing wear on seismic performance of long-span continuous girder bridge","authors":"Chong Li, P. Zhang, Yue Li, Jing-yuan Zhang","doi":"10.21595/jve.2022.22915","DOIUrl":"https://doi.org/10.21595/jve.2022.22915","url":null,"abstract":"To clear the wear effect of friction pendulum bearings (FPBs) on the seismic performance of multiple long-span continuous girder bridges, the rapid sliding performance test of the FPBs was carried out to get the wear degree of the modified poly tetra fluoroethylene (PTFE) wear plates. Taking a 6×110 m long-span continuous girder bridge as the engineering background, the seismic response of the bridge with different wear degrees of the FPBs was analyzed. The results show that the modified PTFE wear plate of the FPBs was severely worn in the rapid sliding performance test, and the friction coefficient was first increased to 0.09 and then decreased to 0.016. When the maximum displacement was reached, the bearing collided with the limitation block. Moreover, the internal forces of the critical pier were increased, and the bottom of the piers entered plasticity due to the wear of the FPBs. Due to the change in the seismic performance of the bridge, it is suggested that the rapid sliding performance of FPBs should be tested to ensure the structure safety of the long-span continuous girder bridge in rare earthquakes.","PeriodicalId":49956,"journal":{"name":"Journal of Vibroengineering","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41683906","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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