Stress-Strain State in a Buckled Thermal Barrier Coating on an Elastic Substrate

Resumo

The paper analyzes the stress-strain state of a thermal barrier coating buckled on an elastic substrate under thermal shock. For the analysis, the stability loss of an orthotropic plate on an elastic substrate (Winkler foundation) is modeled using the Euler method on the assumption that compressive stresses arise in the plate as it expands on heating while the substrate remains cold and dimensionally stable. The deflection amplitude and stresses in the heated plate are determined, and the stress-strain state in the substrate is estimated by solving a plane elastic problem with displacement boundary conditions. The data suggest that both compressive and tensile stresses arise at the coating-substrate interface since the coating becomes unstable and that extrusion and intrusion zones appear in the substrate, showing their chessboard distribution in the plane strain case.