模态分析是水电机组故障诊断的重要方法,但其传统方法缺少对接触部分非线性接触的模拟手段,直接影响模态分析的准确性,也无法对链接部位的失效过程及趋势进行分析。该文基于用户自定义单元子程序接口(user-defined element subroutine i...模态分析是水电机组故障诊断的重要方法,但其传统方法缺少对接触部分非线性接触的模拟手段,直接影响模态分析的准确性,也无法对链接部位的失效过程及趋势进行分析。该文基于用户自定义单元子程序接口(user-defined element subroutine interface,UEL),建立了结合部三维非线性专用分析单元模型。推导所提模型有限元格式的基本方程,获得表征材料非线性特性的本构关系;给出螺栓连接的固定结合部的静态分析,以及立式水轮发电机导轴承支架的模态分析算例;给出导轴承支架的支臂末端螺栓连接变刚度计算的工程应用实例。实验与仿真对比结果表明了建立的UEL三维非线性接触分析专用单元模型的正确性;连接失效分析表明了随着导轴承支架接触刚度的下降,会在整机模态频率计算中引入新的频率段这一结果的重要性。展开更多
A detailed theoretical construction of general coupled 3DFEM analyses of anisotropic dielectrics is first presented by considering the electric body force and body couple moment.A 3Delectrostrictive element is subsequ...A detailed theoretical construction of general coupled 3DFEM analyses of anisotropic dielectrics is first presented by considering the electric body force and body couple moment.A 3Delectrostrictive element is subsequently defined in ABAQUS user subroutine UEL and the post-processing of finite element method(FEM)results is realized by UVARM and dummy element method.Then the developed technique is used to solve the electro-elastic field of an isotropic electrostrictive plate with an elliptical hole subjected to electrical load.By comparing the coupled and uncoupled numerical results,the traditional uncoupled analytical method can cause a large error when the applied electric field or the electrostrictive performance of the dielectric is high,and thus the present coupled analysis is especially necessary.展开更多
文摘模态分析是水电机组故障诊断的重要方法,但其传统方法缺少对接触部分非线性接触的模拟手段,直接影响模态分析的准确性,也无法对链接部位的失效过程及趋势进行分析。该文基于用户自定义单元子程序接口(user-defined element subroutine interface,UEL),建立了结合部三维非线性专用分析单元模型。推导所提模型有限元格式的基本方程,获得表征材料非线性特性的本构关系;给出螺栓连接的固定结合部的静态分析,以及立式水轮发电机导轴承支架的模态分析算例;给出导轴承支架的支臂末端螺栓连接变刚度计算的工程应用实例。实验与仿真对比结果表明了建立的UEL三维非线性接触分析专用单元模型的正确性;连接失效分析表明了随着导轴承支架接触刚度的下降,会在整机模态频率计算中引入新的频率段这一结果的重要性。
基金Supported by the National Natural Science Foundation of China(11232007)the Priority Academic Program Development of Jiangsu Higher Education Institutions+1 种基金the Jiangsu Innovation Program for Graduate Education(CXLX12_0133)the Jiangsu Innovation Program for Graduate Education (the Fundamental Research Funds for the Central Universities)(CXZZ12_0138)
文摘A detailed theoretical construction of general coupled 3DFEM analyses of anisotropic dielectrics is first presented by considering the electric body force and body couple moment.A 3Delectrostrictive element is subsequently defined in ABAQUS user subroutine UEL and the post-processing of finite element method(FEM)results is realized by UVARM and dummy element method.Then the developed technique is used to solve the electro-elastic field of an isotropic electrostrictive plate with an elliptical hole subjected to electrical load.By comparing the coupled and uncoupled numerical results,the traditional uncoupled analytical method can cause a large error when the applied electric field or the electrostrictive performance of the dielectric is high,and thus the present coupled analysis is especially necessary.
