Research On The Influences Of Static And Dynamic Characteristic Of Flange-Bolt Coupling Structure On The Upper Bracket Of Hydraulic Turbine

With the rapid development of the hydropower industry,the structure size of the water turbine generator is increasingly complex and large.The stiffness and strength of the generator structure whether meets the requirements of various operating conditions or not,whether to avoid the vibration unit vibration frequency,these are the problems that need to be solved urgently.Further,the flange bolt connection structure exists in the turbine structure,so that the overall structure or system of the generator has no longer continuity,lead to the complexity of the problem.The performance of bolted joints is an important part of the overall characteristics of the hydro generator,sometimes even as the overall structure damage,weak link failure,so the study of static and dynamic characteristics of the component,must fully consider the connection structure.The influence of the report on the issue,the hydro generator arm bolt on a rack for resolution the object of study,analysis of bolt connection structure of the upper frame of the static and dynamic characteristics of concrete is composed by following several aspects:(1).According to the calculation of "VDI-2230" theory of single bolt joint system,get the bolts and flange rigidity calculation method,and the fixed bolt of a finite element model of stiffness;in addition,the spring based on the superposition principle,get the calculation method of bolt static and dynamic stiffness of the total;(2).Based on a nonlinear finite element analysis model,using ANSYS software to study the bolt pretightening force of bolt diameter and thickness of flange and bolt arrangement effects of different design parameters on the static stiffness of the upper frame;in order to improve the computational effciency,this paper puts forward a simplified calculation method of bolt connection member;(3).The kinetic theory of bolt connection structure based on dynamic analysis model is established for joint,and the finite element analysis of dynamic characteristics of experimental modal identification method of connecting surface parameters,provide the basis for dynamic analysis of hydro generator;(4).The establishment of a dynamic finite element analysis model,combined with the dynamic characteristics of the coupling parameter,influence of bolt pretightening force of bolt diameter and thickness of flange and bolt arrangement of different design parameters on a dynamic frequency;in addition,this paper proposes a simplified bolt connection component dynamic calculation model,and compared with the calculation a practical model shows that:there are some differences between the results of the analysis,the accuracy and reliability of the further study.