Stress Distribution at the Interface Corner of a Tri-Material Structure

The stress distribution at the interface corner between three elastic materials subjected to a uniform change in temperature is examined. A closed-form solution of the stresses near the interface corner is presented. All the parameters in the solution can be determined analytically with the exception of one—the intensity factors of the stress singularity. A method for determining the magnitude of the intensity factors associated with both the dominant singular and the higher-order terms is described. Asymptotic stress results are presented for an asphaltic plug joint used in highway bridges, where the bonding of the plug, bridge deck, and the pavement form an interface corner. It is found here that the effects of small fluctuations in temperature on the magnitude of the stresses are more severe at an interface corner than at the intersection of an interface with a traction-free surface. The implications of the results for the initiation of failure in asphaltic plug joints are discussed.