Analytical determination of adhesive layer deformation for adhesively bonded double cantilever beam test considering elastic–plastic deformation

Abstract

ABSTRACTThe plastic zone at the crack front of an adhesively bonded double cantilever beam (DCB) specimen is analytically expressed considering the deformation of the adhesive layer. The plastic zone length and strain during the crack propagation are obtained, and the effect of the traction–separation profile on the DCB test results is investigated. The fracture energy is given by the area under the traction–separation curve and is not affected by the curve profile. However, the crack length of the DCB specimen is strongly affected by the adhesive deformation, leading to a calculation error in the fracture energy. Therefore, several crack length correction methods have been proposed. An analytical approach to describe the plastic zone at the crack front would help better understand DCB tests for adhesives. In this study, an analytical solution for a DCB test is discussed assuming that the adhesive layer undergoes an elastic–plastic deformation. The elastic zone of the specimen is replaced with a beam on an elastic foundation and the plastic zone with a beam having a uniformly distributed load. Influence of the plastic zone at the crack front in the DCB tests is analytically described by assuming an elastic–perfectly plastic material.