CALCULATING STRAIN-ENERGY RELEASE RATE IN CRACKED ORTHOTROPIC BEAMS

The total strain energy release rate of a homogeneous orthotropic crac ked beam-like structure is calculated using Timoshenko's beam theory. The total strain energy release rate is modified by including the ener gy spent in the deformation of the beam near the crack tip. The contri bution due to the root rotation is obtained by solving an approximatel y equivalent 2-D elasticity problem. By including the contributions du e to the root rotations of the beam segments during crack extension, t he modified beam model prediction of strain energy release rate is sho wn to agree very well with the 2-D finite element results.