Bridge Crane Finite Element Model Updating Based On Sensitivity Analysis

Although the intelligentization of cranes has been proposed for many years,it is still developing slowly and many key issues are still to be solved.The model revision is one of the difficult problems.The modified finite element model can provide technical support for structural response prediction,reliability analysis,damage identification,and fault diagnosis.Therefore,it is of far-reaching significance to study the method of crane model modification.This article focuses on the model modification method for crane structures.The details are as follows:Based on the theoretical analysis of the structural model correction method based on sensitivity analysis,taking the crane structure as the research object,the model correction method for crane structure based on sensitivity analysis was studied.In order to avoid the problem that the design parameter is too large and the calculation volume is large,and some insensitive parameters cause the sensitivity matrix to be ill-conditioned,the sensitivity analysis method is used to optimize the appropriate design parameters to solve this problem.In this paper,the sensitivity calculation method is studied in detail,and the difference method is used to analyze the sensitivity in detail.In order to solve the ill-conditioned problem of the sensitivity matrix in the model correction,the method of weighted feature quantity and correction parameters is improved.Taking a general bridge crane structure of an engineering example as the research object,the feasibility and effectiveness of the model modification method based on the sensitivity analysis in the crane structure are verified.In order to obtain a small,more convenient,and more universal model correction method with a small amount of manual calculations,a model correction method based on ANSYS first-order optimization was selected on the basis of further research on model modification methods.In principle of selection of design parameters,the principle of selection based on sensitivity analysis is followed.In order to achieve the correction error of each frequencywithin the specified range,the error between the finite element frequency and the measured frequency is the state variable,and the state variable is confined within the range specified by the correction error.For the problem that the first-order optimization objective function converges on the local optimal solution,the weighted value of the square of the state variable is used as the objective function,and it can be conveniently judged whether the objective function converges to the local optimal solution.Taking a general bridge crane structure of an engineering example as the research object,the feasibility and effectiveness of the model modification method based on ANSYS first-order optimization in the crane structure are verified.