Modelling of low velocity impacts on unidirectional composite laminates using a semi-continuous strategy

Abstract

This paper deals about the modeling of unidirectional composite laminates under low velocity impacts. The modeling of the composite laminate is based on a semi-continuous representation of the material. The structure is modeled at an intermediate scale between a microscopic and a mesoscopic scale. In each ply, the fibers are modeled with 1D rod elements stabilized by a specific resin shell element. In these elements the membrane and flexural behavior are decoupled. For the in plane loading in the fiber direction it behaves like the resin. In the other directions the stiffness is that of the homogenized ply. The laminate is then built by using specific interface elements. Delamination is modeled using bilinear cohesive laws in mode I, II and III. A low velocity impact test is finally modeled in order to validate this semi-continuous approach. The calculation results well correlate the experimental results.