Volume 16, Issue 3 (May 1988)
Evaluation of Singular Intensity Factors in Elastic-Plastic Materials
A singular intensity factor was evaluated for a butt joint geometry with different adhesive material behavior. The finite element method (FEM) was used for the determination of the stresses and displacements in the joint. It was found that the singular nature of the stress field at the free edge at the intersection between the adhesive and the adherend could be well characterized by a singular intensity factor.
The size of the plastic zone at the bi-material interface was investigated and compared with a simple estimation. It was found that the plastic zone sizes from the numerical analysis were smaller than this estimated zone size, even for a rather large amount of plastic deformation.
The singular stress field, governed by the singular intensity factor, was found to be large compared with the plastic zone size for valid small-scale yielding. This indicates that a fracture criterion based on a critical value of the singular intensity factor may be applicable not only to linear elastic materials but also to non-linear plastic materials.