An Analytical Investigation of Delamination Front Curvature in Double Cantilever Beam Specimens

An analytical investigation is conducted to determine the shape of a growing delamination and the distribution of the energy release rate along the delamination front in a laminated composite double cantilever beam specimen. Distributions of the energy release rate for specimens with straight delamination fronts and delamination front con tours for delaminations whose growth is governed by the fracture criterion that G = G_c at all points are predicted as a function of material properties and delamination length. The predicted delamination front contours are utilized to ascertain the effect of the chang ing shape of the delamination front on the value of the critical strain energy release rate as computed from double cantilever beam fracture toughness test data.