AN ANALYTICAL INVESTIGATION OF DEFORMATION-INDUCED HEATING IN TENSILE TESTING

A numerical method for analyzing non-isothermal viscoplastic deformation problems has been developed. The physical problem is cumbersome because the thermal and deformation effects are coupled both ways, i. e. plastic deformation generates heat and the temperature rise affects material flow behavior. As an application of this method, sheet tensile tests conducted in air have been analyzed using a two-dimensional finite-element formulation. A modified Bishop's method is used to solve the thermo-plasticity problem in decoupled form at each time step. The analysis consists of two main parts: a rigid-plastic finite-element method to analyze the deformation and a transient heat transfer finite-element method, and each part is assumed to occur at sufficiently small, consecutive time steps. Using the present method, the various factors affecting the non-isothermal ductility of material and flow characteristics can be investigated completely.