Thermal shock in an edge-cracked plate subjected to uniform surface heating

Abstract

Thermal shock due to sudden surface heating of an edge-cracked plate is examined and compared with the opposite thermal shock condition that is associated with surface cooling. The plate is assumed to be insulated on one face with convective thermal boundary conditions existing on the side of the plate containing the crack. It is shown that surface heating results in compressive transient thermal stresses close to the plate surface which force the crack surfaces together over a certain contact length. The resulting nonlinear crack contact problem is formulated in terms of a singular integral equation and solved numerically. Calculated results include the transient stress intensity factors for various crack lengths at different values of the Biot number. A result of particular interest is the crack length at which the maximum stress intensity factor during heating exceeds the maximum stress intensity factor for cooling with otherwise identical heat transfer conditions.