Chemical kinetic model of interfacial degradation of adhesive joints

Abstract

The mechanical properties of adhesive joints are degraded in the presence of water. The progressive decrease in strength has been attributed to propagation of interfacial cracks. Water diffusion and the stress distribution within the joint as a function of time are modeled using the finite element method in this study. The stress history at the interface showed spatially invariant characteristics similar to that of interfacial water concentration history as a function of diffusion. The water-stress history along the interface can be modeled as a function dependent principally on water concentration, and is independent of position. On this basis, a chemical kinetic model is proposed to explain the joint strength degradation data reported in literature.