Effects of Fluctuating Moisture and Temperature on the Mechanical Response of Resin-Plates

Abstract

This paper concerns the stress-response of a geometrically constrained resin-slab under externally fluctuating moisture and temperature conditions. The response of the resin is described by a rheologically complex viscoelastic behavior and is analyzed on the basis of the best data that is available at present. The results indicate that the stresses can undergo a change in sign when a test coupon is subjected to a “thermal spike”. This observation may explain the fracture and cracking that has been detected experimentally. In addition, sample results are provided for the residual stresses that develop upon cool-down. It is shown that in this case a subsequent exposure to moisture may contribute to the reduction of such stresses. A brief discussion is provided concerning the diffusion of moisture under fluctuating temperatures.