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

Autor(es)

Carvalho, Pericles R. P. ; Coda, Humberto B. ; Sanches, Rodolfo A. K.

• Tipo de documento: Artigo Científico
• Fonte: EUROPEAN JOURNAL OF MECHANICS A-SOLIDS; v. 97, p. 20-pg., 2023-01-01.

Resumo

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)

• Processo FAPESP: 18/23957-2 - Análise numérica de efeitos termo-mecânicos em sólidos incluindo mudança de fase e situações de contato
• Beneficiário: Péricles Rafael Pavão Carvalho
• Modalidade de apoio: Bolsas no Brasil - Doutorado