Investigation of some regularities of failure of adhesive joints in delamination

Abstract

1. We investigated the dependence of the parameters of failure of adhesive joints type coating-substrate with relatively low level of adhesive interaction between them under conditions of symmetric delamination on the factors determining the rigidity of the coating (its thickness and modulus of elasticity). 2. It was shown that the dependences of the force and angle of delamination in the steady-state process of failure of an adhesive joint on the above-mentioned factors are of opposite nature: when the steady-state force of delamination increases with their increase, the steady-state angle of delamination decreases, and vice versa. 3. On the basis of a quantitative analysis of the given dependences the effect of mutual automatic compensation of the change of these parameters of failure was established; this effect manifests itself by the fact that the product of the steady-state force of delamination and the sine of the angle of delamination does not depend on the rigidity of the coating (its thickness and modulus of elasticity). 4. On examples of various combinations of coatings and substrates it was estabished that the change of the found invariant characteristics of the process of failure of an adhesive joint by the symmetric scheme is qualitatively and quantitatively correlated with the change of adhesive strength in delamination of the coating from the substrate and does not depend on the dimensional parameters of the coating or on its modulus of elasticity.