Rapid quasi-brittle tearing of a thermoelastic strip

Summary The displacement-controlled rapid tearing of a thermoelastic strip is modeled as steady-state propagation of a quasi-brittle crack. The strip satisfies the fully-coupled equations of thermoelasticity, and the small-scale plastic effects are represented by a Dugdale inelastic zone which also serves as a heat flux source. An asymptotic analysis gives expressions for the zone length, COD and dynamic fracture toughness. These expressions show, upon comparison with non-thermal results, the importance of fully-coupled thermoelastic effects, and that all the problem characteristic lengths, which range over several orders of magnitude, are prominent features. Zone heat flux values, based on experimental results for near-crack temperature gradients, are then used for calculation purposes. The calculations show that, independent of a particular fracture criterion, thermal effects noticeably increase inelastic zone size and dynamic fracture toughness.