Dynamic delamination growth in laminated composite structures

Abstract

The dynamic growth of a thin strip delamination in a thick base laminate under in-plane loadings has been analysed. A variational principle, coupled with a Griffith-type fracture criterion, is used to formulate the delamination growth problem. Two approximate solutions, including one mode and two modes, respectively, are calculated in this paper. The resulting equations of motion and the dynamic local growth condition at the crack tip turn out to be two and three coupled ordinary differential equations for one-mode and two-mode solutions. A fourth-order Runge-Kutta method is then used to obtain the numerical solutions. The results show that delamination growth will approach a state of arrest for materials with high fracture toughness, and continue all the way without a limit for low fracture toughness materials. The inertial effect is important and should not be ignored in calculation of the arrested delamination length for high fracture toughness materials. For materials with low fracture toughness, the inertial effect is significant and high admissible modes are noticeable. A comparison between the present results and the previously known quasi-dynamic solution is also given.