A finite element analysis of quasistatic crack growth in a pressure sensitive constrained ductile layer

Polymeric adhesive layers are employed for bonding two components in a wide variety of technological applications, It has been observed that, unlike i n metals, the yield behavior of polymers is affected by the state of hydros tatic stress. In this work, the effect of pressure sensitivity of yielding and layer thickness on quasistatic interfacial crack growth in a ductile ad hesive layer is investigated. To this end, finite deformation, finite eleme nt analyses of a cracked sandwiched layer are carried out under plane strai n, small-scale yielding conditions for a wide range of mode mixities. The D rucker-Prager constitutive equations are employed to represent the behavior of the layer. Crack propagation is simulated through a cohesive zone model , in which the interface is assumed to follow a prescribed traction-separat ion law. The results show that for a given mode mixity, the steady state Fr acture toughness [K](ss) is enhanced as the degree of pressure sensitivity increases. Further, for a given level of pressure sensitivity, [K](ss) incr eases steeply as mode Il loading is approached. (C) 2000 Elsevier Science L td. All rights reserved.