A NUMERICAL STUDY OF STRESS SINGULARITIES IN A 2-MATERIAL WEDGE

A general numerical procedure for determining the stress singularity at the vertex of a two material wedge is presented. Using an eigenfunction expansion technique and assuming the asymptotic displacement field or stress potential to be of the form r(lambda)F(theta), a finite element approach is constructed. The dominant order of stress singularity is determined by solving the eigenvalue equation obtained from the finite element model. Numerical results for some specific problems are given. These results include the order of stress singularities at the free edge of an interface between adjacent layers in a laminated composite, as well as the case of an interface crack in a composite laminate. Results are also obtained by a spectral overlay on a finite element mesh through a least square procedure and show that if high resolution is used near the free edge, a good estimate of singularity can be obtained.