The Unit Bolted Joints Static Feature Modeling And Research

The whole machine is made up of many artifacts through integration of connection,and the connection of two parts is machine joint.Characteristics of integration heavily influence the whole machine features.55%of the total machine tool rigidity,more than 80%of the total damping is the result of machine joint The integration of a bolt 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 in bolt connection,and so on.So studying the characteristics of the integration of a holt is of great significance to improve the performance of machine tool design.In this paper.based on the joint surface characteristic parameters,the static characteristic theory analytical model of unit bolt joint part is established.And influence regularity between bolt pre-tightening.thickness of the flange,bolt specifications,size of surface and the characteristics of integration of a bolt is analyzed.At the same time,the static characteristic analysis model of integration of a cell is built bused on finite element analysis software ABAQUS.And the rationality of the model is validated through the related boll junction experiments.The main work includes:First of all.the theoretical analytical model of single bolt joint is established based on the characteristic parameters.obtaining the analytic formula of static rigidity of the single bolt joint.The influence of pre-load,flange thickness,bolt size awl binding surface size on single bolt joint is analyzed by analyzing static rigidity of the single bolt joint.Secondly,the finite element analytical model of unit bolt joints is established based on the finite element software ABAQUS.By using the subroutine,the static basic characteristic parameters of the unit arc combined with the contact property,and the characteristics of the bolt joint arc accurately resolved.The test device of the bolt joint is set up.including the test device for the bolt pre-tightening force and the torque relations,and the experimental apparatus with the bolt joint.The relation curve of the pre-tightening force and the torque is obtained.The correctness of the analysis method of the bolted joint surface is verified by experiment.Finally,the characteristic model of the four point equivalent unit bolt joints is established The finite element calculation model can be simplified by the obtained equivalent stiffness valu Es,which provides a new method for the analysis of multi bolts in the whole machine.In order to facilitate the application of the nonlinear characteristics of bolt joint,the stiffness charact eristic database of the unit bolt joint is established based on BP algorithm and C#language,and used in a machine tool.