Stress Concentration of a Microvoid Embedded in an Adhesive Layer during Stress Transfer

This paper presents an elastic solution for one microvoid embedded in an adhesive layer close to a stiff bonding surface, which can be approximated as a semiinfinite domain with a fixed boundary. A Green's function for a force in a semiinfinite solid with a fixed boundary condition is used to derive the stress field. By using the equivalent inclusion method, the microvoid has been replaced by the adhesive, but an eigenstrain is introduced to simulate the material mismatch. Through the stress equivalent condition, the eigenstrain is solved, and the stress concentration caused by the microvoid is evaluated considering the stress transfer caused by shear and tensile forces. A uniform normal stress and uniform shear stress are applied in the far field. The formulation is verified with finite-element simulation and can be extended to the case of multiple microvoids. (C) 2014 American Society of Civil Engineers.