In the process of thin-wall parts assembly for an antenna,the parts assembly deformation deviation is occurring due to the riveting assembly.In view of the riveting assembly deformation problems,it can be analyzed thr...In the process of thin-wall parts assembly for an antenna,the parts assembly deformation deviation is occurring due to the riveting assembly.In view of the riveting assembly deformation problems,it can be analyzed through transient and static simulation.In this work,the theoretical deformation model for riveting assembly is established with round head rivet.The simulation analysis for riveting deformation is carried out with the riveting assembly piece including four rivets,which comparing with the measuring points experiment results of riveting test piece through dealing with the experimental data using the point coordinate transform method and the space line fitting method.Simultaneously,the deformation deviation of the overall thin-wall parts assembly structure is analyzed through finite element simulation;and its results are verified by the measuring experiment for riveting assembly with the deformation deviation of some key points on the thin-wall parts.Through the comparison analysis,it is shown that the simulation results agree well with the experimental results,which proves the correctness and effectiveness of the theoretical analysis,simulation results and the given experiment data processing method.Through the study on the riveting assembly for thin-wall parts,it will provide a theoretical foundation for improving thin-wall parts assembly quality of large antenna in future.展开更多
A three-dimensional finite element simulation was carried out to investigate the effects of tunnel construction on nearby pile foundation.The displacement controlled model (DCM) was used to simulate the tunneling-indu...A three-dimensional finite element simulation was carried out to investigate the effects of tunnel construction on nearby pile foundation.The displacement controlled model (DCM) was used to simulate the tunneling-induced volume loss effects.The numerical model was verified based on the results of a centrifuge test and a set of parametric studies was implemented based on this model.There is good agreement between the trend of the results of the centrifuge test and the present model.The results of parametric studies show that the tunnelling-induced pile internal force and deformation depend mainly on the pile?tunnel distance,the pile length to tunnel depth ratio and the volume loss.Two different zones are separated by a 45° line projected from the tunnel springline.Within the zone of influence,the pile is subjected to tensile force and large settlement;whereas outside the zone of influence,dragload and small settlement are induced.It is also established that the impact of tunnelling on a pile group is substantially smaller as compared with a single pile in the same location with the rear pile in a group,demonstrating a positive pile group effect.展开更多
针对重型工程车轮在径向载荷工况下有限元分析(Finite Element Analysis,FEA)的不准确问题,基于车轮-轮胎接触压力测试结果,构建了一种新的仿真分析模型。首先,测试车轮仅在充气压力工况下的应力数据,并以4阶高斯函数拟合充气压力加载模...针对重型工程车轮在径向载荷工况下有限元分析(Finite Element Analysis,FEA)的不准确问题,基于车轮-轮胎接触压力测试结果,构建了一种新的仿真分析模型。首先,测试车轮仅在充气压力工况下的应力数据,并以4阶高斯函数拟合充气压力加载模型;然后,测试车轮在充气压力和径向载荷共同作用下的应力数据,消去充气压力的影响,并以4阶傅里叶函数和4阶正弦和函数分别拟合径向载荷周向加载模型和轴向加载模型;最后,通过Ansys软件仿真验证加载模型。结果显示,与实测数据相比,关键校核点的计算误差仅为1.943%。此外,应力分布也显示出高度的一致性,证明了径向接触压力分布模型的准确性和可靠性较高。展开更多
基金Project(51675100)supported by the National Natural Science Foundation of ChinaProject(2016ZX04004008)supported by the National Numerical Control Equipment Major Project of ChinaProject(6902002116)supported by the Foundation of Certain Ministry of China
文摘In the process of thin-wall parts assembly for an antenna,the parts assembly deformation deviation is occurring due to the riveting assembly.In view of the riveting assembly deformation problems,it can be analyzed through transient and static simulation.In this work,the theoretical deformation model for riveting assembly is established with round head rivet.The simulation analysis for riveting deformation is carried out with the riveting assembly piece including four rivets,which comparing with the measuring points experiment results of riveting test piece through dealing with the experimental data using the point coordinate transform method and the space line fitting method.Simultaneously,the deformation deviation of the overall thin-wall parts assembly structure is analyzed through finite element simulation;and its results are verified by the measuring experiment for riveting assembly with the deformation deviation of some key points on the thin-wall parts.Through the comparison analysis,it is shown that the simulation results agree well with the experimental results,which proves the correctness and effectiveness of the theoretical analysis,simulation results and the given experiment data processing method.Through the study on the riveting assembly for thin-wall parts,it will provide a theoretical foundation for improving thin-wall parts assembly quality of large antenna in future.
文摘A three-dimensional finite element simulation was carried out to investigate the effects of tunnel construction on nearby pile foundation.The displacement controlled model (DCM) was used to simulate the tunneling-induced volume loss effects.The numerical model was verified based on the results of a centrifuge test and a set of parametric studies was implemented based on this model.There is good agreement between the trend of the results of the centrifuge test and the present model.The results of parametric studies show that the tunnelling-induced pile internal force and deformation depend mainly on the pile?tunnel distance,the pile length to tunnel depth ratio and the volume loss.Two different zones are separated by a 45° line projected from the tunnel springline.Within the zone of influence,the pile is subjected to tensile force and large settlement;whereas outside the zone of influence,dragload and small settlement are induced.It is also established that the impact of tunnelling on a pile group is substantially smaller as compared with a single pile in the same location with the rear pile in a group,demonstrating a positive pile group effect.
文摘针对重型工程车轮在径向载荷工况下有限元分析(Finite Element Analysis,FEA)的不准确问题,基于车轮-轮胎接触压力测试结果,构建了一种新的仿真分析模型。首先,测试车轮仅在充气压力工况下的应力数据,并以4阶高斯函数拟合充气压力加载模型;然后,测试车轮在充气压力和径向载荷共同作用下的应力数据,消去充气压力的影响,并以4阶傅里叶函数和4阶正弦和函数分别拟合径向载荷周向加载模型和轴向加载模型;最后,通过Ansys软件仿真验证加载模型。结果显示,与实测数据相比,关键校核点的计算误差仅为1.943%。此外,应力分布也显示出高度的一致性,证明了径向接触压力分布模型的准确性和可靠性较高。
