Performance of Cohesive Zone Models for Brittle and Ductile Adhesives

Abstract

Damage modeling approach is increasingly used to simulate fracture and debonding processes in adhesively bonded joint. In order to understand the relation between the delamination behavior of different types of adhesives and the type of cohesive zone models (CZMs), the pure tension and pure shear experiments were conducted used two distinct adhesives, an epoxy-based adhesive in a brittle manner and VHBTM tape adhesive in a ductile manner. The traction-separation relations of the two adhesives were extracted from the tension and shear experimental results. Three types of cohesive zone models (CZMs) are adopted, including the exponential, bilinear, and trapezoidal models. VUMAT subroutine of CZMs as the adhesive layer is used to simulate the specimen tension and shear debonding procedures. The results demonstrate that (i) the bilinear CZM more suitably describes the brittle adhesive and the exponential CZM suitably describes the ductile adhesive to simulate the tension and shear failure. (ii) cohesive strength and work of separation are the significant affections on the simulation results. and (iii) the shape of CZM is a significant affections on the simulation the pure tension and shear debonding procedure.