A large strain thermodynamically-based viscoelastic-viscoplastic model with application to finite element analysis of polytetrafluoroethylene (PTFE)

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Author(s):	Carvalho, Pericles R. P. ; Coda, Humberto B. ; Sanches, Rodolfo A. K. Total Authors: 3
Document type:	Journal article
Source:	EUROPEAN JOURNAL OF MECHANICS A-SOLIDS; v. 97, p. 20-pg., 2023-01-01.
Abstract
We propose a phenomenological viscoelastic-viscoplastic model to simulate the large strain constitutive response of polymeric materials. The formulation is developed in a thermodynamic framework, based on the multiplicative decomposition of elastic, viscous and plastic deformation components. For the viscoplastic part, we use a Perzyna-like model including two components of kinematic hardening, one with pseudo-viscous evolution (Armstrong-Frederick model), and the other with real viscosity, so that the rate-dependency of the plastic stiffness is taken into account. The proposed model is implemented in a large-deformation finite element framework and applied to numerical simulations. The constitutive parameters are calibrated for the material polytetrafluoroethylene (PTFE) using uniaxial monotonic tests featuring different strain rates, and later validated with creep and relaxation experimental results. Finally, mesh and time convergence analyses are carried out in representative examples. (AU)

FAPESP's process:	18/23957-2 - Numerical analysis of thermo-mechanical effects in solids including phase change and contact
Grantee:	Péricles Rafael Pavão Carvalho
Support Opportunities:	Scholarships in Brazil - Doctorate