MCT failure analysis of variable stiffness composite plate with a central hole

Abstract

Steered-fiber placement has been a very interesting approach to enhance the mechanical properties of fiber-reinforced composite structures, especially with holes. Based on flow field theory and the Levenberg–Marquardt algorithm, the fiber orientations on a variable stiffness (VS) ply in a composite plate with a central hole are represented and optimized. The fiber orientations on the VS plies are aligned with those of the maximum principal stress as much as possible. By transforming the complex planning problem of curvilinear trajectory into the function design of a scalar field, this method leads to better efficiency and general optimization. Comparative failure analysis based on the MCT criterion shows that the VS model has a 197% higher capability for initial damage and a 97% higher capability for ultimate load. The contour plots of the failure state and the load–displacement plots also certify the validity and the feasibilities of the proposed VS planning method.