Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9711641 | Mechanics of Materials | 2005 | 18 Pages |
Abstract
An endochronic viscoplastic approach, derived from the theory of finite viscoplasticity based on isomorphisms, is presented. The model allows to characterize viscoplastic material behaviour with equilibrium hysteresis using a rate-independent elastoplastic model with an endochronic flow rule and a logarithmic elastic law in parallel connection with a non-linear Maxwell model. The volumetric strains are assumed to be purely elastic. The proposed model describes the non-linear mechanical behaviour of thermoplastic materials such as filled polytetrafluoroethylene (PTFE). The temperature and filler volume fraction dependencies of the model parameters have been identified by a Levenberg-Marquardt algorithm. In contrast to previous suggestions, the proposed model is capable to describe both the non-linearities during strain controlled loading and the non-linearities during stress controlled unloading in a unified approach. The results of the numerical simulations are in fair agreement with the experimental data.
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Mechanical Engineering
Authors
Thomas Kletschkowski, Uwe Schomburg, Albrecht Bertram,