Coupled thermo-mechanical model was used to investigate the effects of the pin diameter, the shoulder diameter and the in conical angle on the heat generations, the material deformations and the energy histories in fr...Coupled thermo-mechanical model was used to investigate the effects of the pin diameter, the shoulder diameter and the in conical angle on the heat generations, the material deformations and the energy histories in friction stir welding（FSW） of AA2024-T3 alloy. Results indicate that the shoulder-plate contact area takes more important contribution to the heat generation than the pin-plate contact area. The increase of the shoulder diameter or the decrease of the pin diameter can lead to the increase of the welding temperature in FSW, but the change of shoulder size is more important. Compared to the cases in FSW of AA6061-T6, the input power is obviously increased in FSW of AA2024-T3 and the ratio of the plastic dissipation to the friction dissipation becomes decreased.展开更多
The topography of gear meshing interfaces is one of the key factors affecting the dynamic characteristics of the gear transmission system.In order to obtain the contact characteristics of meshing gear pair with differ...The topography of gear meshing interfaces is one of the key factors affecting the dynamic characteristics of the gear transmission system.In order to obtain the contact characteristics of meshing gear pair with different surface micro-topographies,an interface feature model and a tribo-dynamics coupling model for the gear system are proposed in this paper.The effects of the gear tooth surface micro-topography on the oil film distribution,contact damping and friction are considered.The time-varying meshing stiffness and the static transmission error are included in the abovementioned models.An exemplary gear pair is analyzed using the proposed models to investigate the influence of the surface micro-topography on the dynamic characteristics of gear system under different micro-topographies and input torque conditions.Simulation results show that the effects of gear tooth micro-topography on the gear dynamic responses(including the friction and the vicious damping at the gear meshing interface and the vibration in the direction of offline of action)are highly dependent on the regularity of tooth surface.The vibration and noise can be significantly controlled by manufacturing a regular gear tooth profiles instead of random profiles.展开更多
基金Project(NCET-12-0075)supported by the Program for New Century Excellent Talents in University,ChinaProject supported by the Fundamental Research Funds for the Central Universities,China+2 种基金Projects(11172057,11232003)supported by the National Natural Science Foundation of ChinaProject(2011CB013401)supported by the National Basic Research Program of ChinaProject(2012AA050901)supported by the National High-Tech Research and Development Program of China
文摘Coupled thermo-mechanical model was used to investigate the effects of the pin diameter, the shoulder diameter and the in conical angle on the heat generations, the material deformations and the energy histories in friction stir welding（FSW） of AA2024-T3 alloy. Results indicate that the shoulder-plate contact area takes more important contribution to the heat generation than the pin-plate contact area. The increase of the shoulder diameter or the decrease of the pin diameter can lead to the increase of the welding temperature in FSW, but the change of shoulder size is more important. Compared to the cases in FSW of AA6061-T6, the input power is obviously increased in FSW of AA2024-T3 and the ratio of the plastic dissipation to the friction dissipation becomes decreased.
基金Projects(51905053,51805051)supported by the National Natural Science Foundation of ChinaProject(cstc2019jcyj-bshX0119)supported by the Chongqing Postdoctoral Science Foundation,China。
文摘The topography of gear meshing interfaces is one of the key factors affecting the dynamic characteristics of the gear transmission system.In order to obtain the contact characteristics of meshing gear pair with different surface micro-topographies,an interface feature model and a tribo-dynamics coupling model for the gear system are proposed in this paper.The effects of the gear tooth surface micro-topography on the oil film distribution,contact damping and friction are considered.The time-varying meshing stiffness and the static transmission error are included in the abovementioned models.An exemplary gear pair is analyzed using the proposed models to investigate the influence of the surface micro-topography on the dynamic characteristics of gear system under different micro-topographies and input torque conditions.Simulation results show that the effects of gear tooth micro-topography on the gear dynamic responses(including the friction and the vicious damping at the gear meshing interface and the vibration in the direction of offline of action)are highly dependent on the regularity of tooth surface.The vibration and noise can be significantly controlled by manufacturing a regular gear tooth profiles instead of random profiles.
