Mehdi Fakoori - M.S student, Amirkabir University of Technology, Faculty of Marine Technology
Mohammad Rezai Sangtabi - Ph.D student, Amirkabir University of Technology, Faculty of Marine Technology
Hossien Sadeghi - M.S student, Amirkabir University of Technology, Faculty of Marine Technology

Response of curved composite sandwich panels subjected to static and dynamic loading is predicted using finite element (FE) method. At first a FE model based on the classical sandwich plate theory is developed to consider geometrical nonlinear effects. Simple failure mechanism based on the progressive damage model is included in the analysis. Failure mode for laminate of sandwich skins including ply-ply damage, which are matrix in addition to the fiber failure in the each layer by using modified Hashin-Rotem criterion. Shear failure within the core is predicted based on the Hill-Tsai criterion. Degradation of mechanical properties in the failed layers of an element is carried out according to the ply discount rules. In order to study the progressive damage procedure, a user subroutine code is coupled with another FE code to calculating the stresses in the Gaussian points inside each layer of an element. As effects of important problem parameters, such as stacking sequence of plies, density of core and core thickness are studied.

Curved Composite Sandwich Panels,Progressive Damage Model, Degradation, Finite Element Method