Simulating stress intensity factors for anisotropic materials by the least-squares method

The main purpose of this paper is to investigate the accuracy of the least-squares method incorporating the finite element method for finding the stress intensity factors of composite materials. Numerical simulations in this paper indicate that the least-squares method can be used to calculate stress intensity factors accurately, if seven or eight displacements terms are included. The calculated stress intensity factors by using the least-squares method can be as accurate as the calculated J-integrals by using the J-integral formulation. If seven or eight displacement terms are included, the calculated stress intensity factors of this method are independent of the maximum radius of the area from which data is included; furthermore, a very fine mesh is also not necessary.