Ansysis And Research Of Multi-bolt Joints Static Characteristic

The whole machine is made up of many artifacts through integration of connection,and the connection of two parts is machine joint.Bolt joint is widely used in machine tool structure of fixed connection,such as machine tool lathe bed and stud bolt connection,machine tool guide-way,the spindle flange bolt connection,and so on.It heavily influence the whole machine features.So studying the characteristics of bolt joint is of great significance to improve the performance of machine tool design.In this paper,based on the basic characteristic parameters of joint surface,the static characteristic theory analytical model of bolt joint is established.Influence regularity between bolt pre-tightening,bolt specifications and the characteristics of bolt joint is analyzed.The static characteristic analysis model of bolt joint is built based on finite element analysis software ABAQUS.And the rationality of the model is validated through the related bolt junction experiments.The bolt junction characteristics is studied and six springs equivalent unit bolt j unction characteristics model is established.The main research work includes:First of all,the theoretical analytical model of bolt joint is established based on the basic characteristic parameters of joint surface,obtaining the analytic formula of static rigidity of the bolt joint.The influence rule of pre-load and bolt size on bolt joint is analyzed by analyzing static rigidity of the bolt joint.Secondly,combine the unit surface static foundation characteristic parameters to contact properties,based on the finite element analysis software ABAQUS to establish a static characteristic analysis model of the bolt joints.The influence rule of pre-load and bolt size on bolt joint is also analyzed by analyzing static rigidity of the bolt joint.And the model of multi-bolt joints is analyzed.The influence law between number of bolts and feature of bolt joint is obtained and the influence of various influence factors of bolt joint features also.Then the test device of the bolt joint is set up.The correctness of the analysis method of finite element is verified by experiment.Finally,the characteristic model of the six springs equivalent unit bolt joint is established.The finite element calculation model can be simplified by the obtained equivalent stiffness values,which provides a new method for the analysis of multi-bolt in the whole machine.