A study of a cyclic viscoplasticity model based on hyperbolic sine form for the inelastic strain rate

The viscoplastic hyperbolic sine form which describes the inelastic strain rate is combined with the Ohno-Wang kinematic hardening rule. Experiments under monotonic tensile loads at different strain rates as well as under cyclic loadings are used to obtain all model parameters with the trial and error method. The effects of strain jumps of the stress, the saturated visco-plasticity behavior under cyclic loadings and the stress relaxation for several metallic materials are simulated. The usage of the exponential form instead of the hyperbolic sine form for the inelastic strain rate is discussed finally. (C) 2015 Elsevier Ltd. All rights reserved.