Stress near apex of dissimilar material with bilinear behavior

This study presents an analytical solution for the asymptotic stress field near the apex of a wedge composed of dissimilar materials exhibiting elasti c and/or plastic deformation that can be described by a bilinear material m odel. Under the same assumptions, previous investigations resulted in eigen value differential equations that were not amenable to analytical integrati on. The present formulation avoids the numerical integration of such equati ons. After establishing its validity, the corner of the junction formed bet ween a solder ball and a substrate was considered in order the study the ef fect of the hardening parameter on the strength of the singular stress fiel d. Also, this formulation provides the exact form of the displacement field , which permits the construction of a global element to capture the correct strength of the singular stress field in regions with material and geometr ic discontinuities. (C) 1999 Elsevier Science B.V. All rights reserved.