Numerical Study On Nonlinear Buckling Testing Method Of Hat-Stiffened Composite Plate

Stiffened composite plate is widely used in aircraft, spacecraft and other structure for its superior performance. Stiffened plate buckling will show under shear load, but the structure failure will not occur immediately, and the load-carrying capacity that these structures still have is generally named post-buckling strength. Thus in order to control structure failure and take full advantage of post-buckling load-carrying capacity of laminated structures to increase failure resistance, it is necessary to investigate the buckling and post-buckling behavior characteristic.At first , geometrical nonlinear problems in post-buckling are analyzed in details. The model of hat-stiffened laminate composite panel was established. The buckling and post-buckling in shear loaded panels was simulated using the finite element method. Critical buckling load and buckling mode shape was obtained through linear buckling analysis. The post-buckled equilibrium paths were obtained using buckling analysis based on arc-length method after linear buckling analysis. The buckling critical load and the load-displacement relationship with different factors were analyzed. The effect of initial deflection, thickness and plies configuration,layers and foam of stiffeners number and plies configuration on the buckling and post-buckling behavior characteristic of composite panels are discussed , respectively.In order investigate effects of the experiment setup parameters on the test, a model including loading rig, clamping transition section, and fastener was established. The maximum stress and strain and displacement were obtained, and then the effects of test device parameters were presented, so the proper thickness of steel clamps, transition plied configuration and fastener diameter are determined.