Nonfactorizable viscoelastic behavior: modeling and identification

Adel Tayeb (1, 2) , A-M Zine (3, 4) , M Arfaoui , M Ichchou (2) , A Hamdi , J Benabdallah

1 LR-MAI-ENIT - Laboratoire de Mécanique Appliquée et Ingénierie [Tunis]
2 LTDS - Laboratoire de Tribologie et Dynamique des Systèmes
3 ICJ - Institut Camille Jordan
4 MMCS - Modélisation mathématique, calcul scientifique

A three dimensional viscoelastic model at finite strain representing nonfactorizable behaviour of rubber like materials is proposed. The model is based upon the internal state variables approach within the framework of rational thermodynamics such that the second principle of thermodynamics is satisfied. Motivated by experimental and rheological results, the nonfactorizable aspect of the behavior was introduced via strain dependent relaxation times which leads to a reduced time with a strain shift function. The identification of the models parameters and its capacity to predict the nonfactorizable behaviour of rubber like materials with respect to experimental data and the multi-integral viscoelastic model of Pipkin have been addressed in a previous work. The main concern of this work is the representation of the implementation of constitutive equations following from this model into Abaqus finite element software via a Fortran UMAT subroutine. To this end, the deformation gradient split into a volumetric and isochoric parts was employed, then the so-called tangent module was computed for a Mooney-Rivlin hyperelastic material. Finally, the computation of the integral in the model was computed using midpoint method. The validation of the UMAT was carried using homogeneous transformations of simple extension and pure shear.

Domaines: Mécanique [physics]

Adel Tayeb, A-M Zine, M Arfaoui, M Ichchou, A Hamdi, et al.. Nonfactorizable viscoelastic behavior: modeling and identification. MEDYNA 2017: 2nd Euro-Mediterranean Conference on Structural Dynamics and Vibroacoustics, Apr 2017, Séville, Spain. ⟨hal-03343015⟩