Coupling Reliability Analysis Of Multiple Failure Modes For Stiffened Composite Panels

Stiffened composite panels structure is a typical structure in engineering.In the process of axial compression failure,the failure mode is complicated with the alternates of fiber,matrix and adhesive layer.To ensure the safety of the structure,the multiple failure mode of coupling reliability analysis and the ultimate bearing capacity reliability analysis are required.Therefore,how to determine the influence of failure modes on structural reliability and improve the efficiency of structural reliability analysis is one of the problems to be solved in the field of composite material structure design.1.Progressive failure analysisThe stiffness degradation and multiple failure mode coupling problem of matrix,fiber and adhesive layer of composite stiffened plate under axial compression was investigated.Through abaqus software,a user subprogram with progressive failure analysis is written to calculate the structure compression performance.By comparing the simulation results with the experimental data,the rationality of the model is shown.2.Multiple failure mode coupling reliability analysisHashin failure criterion and Quads failure criterion is adopted to establish the limit state equation,and by the first order second moment method of stiffened plate,respectively,with the single failure mode and failure mode coupling for reliability analysis,and related parameters affecting the stiffened panel of compression performance are analyzed.The result show that the material of vertical and transverse elastic modulus of stiffened plate had a greater influence on the reliability,and the influence of material of shear modulus of stiffened plate is relatively small.3.Reliability analysis of ultimate bearing capacityThrough the analysis of the basic random parameters that affect the buckling load and ultimate compression strength of stiffened plates,the ultimate compressive strength function is constructed by buckling load and coefficient.The reliability analysis of stiffened panel ultimate bearing capacity is carried out.This paper has a higher computational efficiency than the classical method,which is convenient for engineering calculation.In addition,the buckling load plus coefficient is used to optimize the load-bearing capacity of the stiffened plate,and the weight loss is obvious.