Photoelastic analysis of the singular stress field in a bimaterial wedge

This paper presents an experimental investigation of the singular stress fi eld near the vertex of a bimaterial wedge using a digital photoelastic tech nique. Special attention is given to the casting of bimaterial wedge specim ens and analysis technique for extracting stress intensity factors from pho toelastic samples. Different bimaterial wedge specimens are made of two dif ferent photoelastic materials bonded through a special casting procedure an d loaded in simple tension. A new multiple-parameter method is developed to obtain the stress intensity factor reliably from the isochromatic fringe p atterns and the series representation of the stress field at the vertex of the wedge. Experimental results are compared with finite element prediction s, and good agreement is observed.