Automatic correction of the time step in implicit simulations of thermomechanical problems

The accurate numerical modelling of thermomechanical systems is important in several industrial applications. A new staggered coupling strategy is proposed to deal with thermo-elasto-plastic problems involving large deformations and rotations, which is combined with an automatic time-step control technique. The proposed strategy is based on the isothermal split approach. It differs from the classical scheme since, in each increment, there are two phases of interchange of information, instead of only one. In each increment, the solution procedure is divided in a prediction phase and a corrector phase, and the interchange of information is performed on both. The proposed strategy was implemented in the in-house quasi-static finite element code DD3IMP. Its performance is analysed and compared with the classical strategy and the iterative one, which are commonly employed for solving thermomechanical problems. The results indicate that the propose strategy contributes for improving the accuracy of the numerical solution, with a reasonable computational cost.