Shear Buckling And Postbuckling Behavior Of Laminated Composite Plates

It is commen to cause baleful aftereffect for the composite laminated thin-walled structures buckling failure in shear. In fact, laminated plates under buckling do not fail, and these structure can still have a reasonable load-carrying capacity, which is gennerally named post-buckling strength. Thus in order to control structure fatigue and take full advatage of post-buckling load-carrying capacity of laminated structures to increase fatigue resistance, it is necessary to investigate the buckling and post-buckling behavior characteristic.At the first of this paper, buckling test in shear was investigated for delaminated composite panels , the experimental results compared with the finite element method simulant results were analyzed to propose the influences of the delaminated area on the shear buckling properties. The results of experimentation indicate that the failure load of the delaminated composite panels declines and the failure strain increases as the increasing of delaminated area. So the delamination can decrease the carrying capacity and the stiffness of the composite panels. The buckling critical load and the capacity of anti-buckling of the specimen decline with the increasing of the delaminated area.In this paper, geometrical nonlinear problems in post-buckling are analysed in details.The buckling and post-buckling in shear of delaminated composite panels with and without stiffeners are simulated by using the finite element modeling .The buckling critical load and the post-buckled equilibrium paths were obtained. And the buckling critical load and the load-displacement curves with different factors were analysed. The effect of initial deflection, thickness and layers of plate and number , height and layers of stiffeners on the buckling and post-buckling behavior characteristic of composite panels are respectively discussed in detail.