Identification Method for Dynamic Properties of Bolted Joints

The ill-posed problem is produced by its non-linear property of bolted joints,noise effect and numerical error at using the frequency response functions(FRFs) to identify parameters of bolted joints.In order to avoid the ill-posed problem,the normal and tangential dynamic model of bolted joints is established by sub-structure synthesized method,and using weighted function method to make the coefficients of each identification equations maintaining at the same level.Then using the FRFs method to identify parameters of bolted joints,respectivity,the identification results are regarded as the initial numerical values and calculated the sensitivity by iterative method in the whole frequency range.In the end,the experimental data is selected by sensitivity method and then to identify the parameters of bolted joints.From the results of experiment and verification,results show that the proposed method can significantly improve the accuracy of identification,and the sensitivity method can be used to avoid the ill-conditioned problem.