A Numerical Study on Failure Strength of CFRP Laminates with Impact Damage

Abstract

Compression behavior and failure mechanism of impact damged composite laminates are numerically discussed by using finite element method to explain the compression strength reduction due to barely-visible-damage (CAI). Impact damage is modeled as a double-spiral-shape damage consisting of delaminations and matrix cracks. The numerical results considering geometrical nonlinearity and cantact condition show that buckling of the entire damage area causes a rapid increase of the energy release rate and the compressive stress beside damage area. The failure load is investigated through energy release rate distribution along the delamination front and the stress concentration at the side of the buckled portion. The failure problem is discussed through parametric study of the material properties.