engleski

Nonlinear kinematic hardening in coupled thermoplasticity

Paper deals with permanent deformation of metals within nonisothermal environment. As it is generally known, metals are easier shaped if the specimen in heated. Furthermore, dimensions of an object also change with temperature variation. In that way, thermal effects influence mechanical behavior. Vice-versa, the plastic deformation is accompanied by the heat release that influences temperature field. Therefore, the problem is of coupled nature. To define this problem, we briefly state governing equations. Constitutive equations must be able to model both isotropic hardening and kinematic hardening. Nonlinear kinematic hardening is of special interest. Widely used plasticity models, the so-called associated plasticity models, are not able to model these nonlinearities. Consequently, to gain possibility of description of cyclic processes through nonlinear kinematic hardening, one must use concepts of non-associated plasticity. To solve the problem at hand we propose numerical framework. The cornerstone is finite element method. We also present decoupling technique along with procedures that deal with nonlinearities. At the end, an example is provided and some conclusions are drawn.

Thermomechanics; Cyclic plasticity; Non-linear kinematic hardening; Coupled problems; Finite element method

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