Fracture characterization for thermoinelasticity

The research develops and verifies the path domain independent integral S that is exactly the energy release rate for an extending crack within a thermoinelastic material response region. Emanating from thermoinelastic continuum mechanics and Noether's theorem from classical field theory, the S integral defines the force acting on an extending crack and represents a conservation law for a crack free body. Limited physical experiments and computational investigations verify the S integral for uncoupled thermoinelasticity. S offers a parameter to improve the understanding of the strength and reliability of materials subjected to thermomechanical loadings.;The theoretical development produces the S path domain independent integral for two quasi static cases; uncoupled thermoinelasticity and fully coupled thermoinelasticity. Proofs demonstrate the path domain independence and the total energy release rate aspects of the S integral.;A limited experimental program and an associated computational investigation verifies that the S integral characterizes fracture for uncoupled thermoinelasticity. Experiments on a crack free aluminum sheet and finite element results from a simple dogbone specimen verify the S conservation law. Fracture resistance tests on aluminum 2024 demonstrate that S equals the crack driving force under thermomechanical loadings. The fracture resistance experiments consider two specimen geometries and two specimen thicknesses.