Finite element modeling of crack growth and failure of composite laminates

A finite-element method for analysis of fiber-reinforced composite laminates is presented. Loads required to cause failure of the laminates as well as stress intensity factors for mode I and II problems are solved. The models used assume no out of plane bending, linear-elastic material behavior, and homogeneous orthotropic material. The method uses Barsoum's eight node quadrilateral isoparametric element in the displacement finite element technique to solve for stresses within the laminate. The Tsai-Hill failure criterion is used to predict ply failure within the laminate for the first group of problems solved. The second type of problem uses the J-integral method along with the strain energy density criterion to determine mode I and mode II stress intensity factors as well as direction of crack growth. Several examples are presented, and results show excellent agreement with published results for similar problems. The procedure is very efficient and produces excellent results with a relatively small number of finite elements. The element mesh and nodal points are also generated by the computer for accuracy and to save time