ABSTRACT
The plan of the paper is as follows. The formulation of the PRF model available in Abaqus is discussed in Section 2, followed by validation examples in Section 3 and conclusions in Section 4.
2 FORMULATION
The framework consists of an arbitrary number, N, of viscoelastic networks connected in parallel, as shown in Figure 1. In addition, we consider an equilibrium network which can be purely elastic or elasto-plastic (network 0 in Fig. 1). If the elastic network is not defined, the stress in the material will relax completely over time; otherwise, the stress will relax to a residual value, which is different from zero. The addition of plasticity to the equilibrium network allows for modeling permanent set upon load removal.
