Temperature rise due to fast-moving dislocations

In this paper, the method of discrete dislocation plasticity (DDP) is exten ded to include explicitly the thermal effects of moving dislocations. In th is manner, localization of heat during fast deformation can be calculated e xactly. The thermal effects included are the thermal dissipation due to dis location drag, the temperature dependence of the drag coefficients themselv es and a temperature-dependent obstacle strength through a simple Arrhenius -type dependence. An analytical solution is presented and the temperature d istribution is calculated using a time-dependent Galerkin finite-element so lution. The two solutions are compared to provide a mutual validation. Then , the stress-strain curves are calculated for Al under simple shear for con stant temperatures of 100, 298 and 900 K. The stress-strain curves reflect the temperature dependence of the drag coefficients, since the deformation takes place at a strain rate of 10(6) s(1), which is well within the drag-c ontrolled regime. Finally, the temperature distributions for Al and Ti are calculated. At 7.5% shear strain, the maximum temperature rise is of the or der of 20 K in Ti. This is orders of magnitude lower than the melting tempe rature, the temperature which has experimentally observed to be reached. It is anticipated that this is caused by crack propagation which will be mode lled by a DDP approach in future work.