Model Updating Of Bolted Connection Structure Based On Model Reduction

Bolt connections are widely used in engineering structures.In the analysis of the dynamic characteristics of a large complex structure,the efficiency of modeling and solving will be greatly reduced if the detailed model of the bolt connection structure is considered.If iterative optimization or multiple computation is needed,the amount of computation increases dramatically.Therefore,it is very important to study the simplified modeling method of the bolt connection structure and obtain the accurate connection stiffness to improve the accuracy of the overall structure analysis and the efficiency of the optimization design.Model correction technique,as the main method to reverse the parameters of the system,can be used to modify the simplified modeling parameters of the bolt connection structure,and the model reduction technique can be used to improve the efficiency of the model correction.In this paper,the precision of the model reduction method and its applicability in the process of model updating are studied in this paper.The simplified modeling method of the bolt connection structure is studied for the long tube shell with bolt connection,and the simplified part of the bolt connection is updated based on the reduced order model.The main contents of the article can be summarized as follows:1.For the long slender beam structure,the local rigid model reduction method based on the motion synchronization hypothesis,the single point condensation and the multi point condensation method based on the flat section assumption,the Guyan static condensation method,the Kuhar dynamic condensation method and the improved system reduction method(IRS method)are studied.Through Matlab and commercial finite element software ABAQUS,a number of reduced order model of long thin beam structure based on the above method is established.The calculation efficiency and accuracy of each method are compared by an example,and the applicability of each method in the model correction is discussed.2.For cylindrical shell with bolt connection structure,the simplified modeling method of bolt connection structure is studied.Through the combination of multidisciplinary optimization software Isight and Matlab,a genetic algorithm is used to modify the simplified part.In order to reduce the time of single calculation in the optimization iteration process,the whole structure is divided into several segments,and the IRS method is used to further reduce the whole structure,and the model correction is carried out on the basis of the reduced order model,which improves the efficiency of the model correction.