Phenomenological multi-mechanisms constitutive modelling for thermoplastic polymers, implicit implementation and experimental validation. (November 2017)

• Record Type: Journal Article
• Authors: Praud, F.; Chatzigeorgiou, G.; Bikard, J.; Meraghni, F.
• Is Part Of: Mechanics of materials. Volume 114(2017)
• Page Start: 9
• Page End: 29
• Publication Date: 2017-11
• Subjects: Constitutive behaviour -- Viscoelasticity -- Viscoplasticity -- Ductile damage -- Implicit implementation -- Polymers; Strength of materials -- Periodicals; Mechanics, Applied -- Periodicals; Résistance des matériaux -- Périodiques; Mécanique appliquée -- Périodiques; Mechanics, Applied; Strength of materials; Periodicals; Electronic journals; 620.11
• DOI: 10.1016/j.mechmat.2017.07.001
• Languages: English
• ISSNs: 0167-6636

Abstract

Highlights: A phenomenological model for thermoplastic polymers accounting for viscoelastic, viscoplastic and damage mechanisms is proposed. An implicit numerical scheme is provided along with the formulation of the tangent operator. The model parameters are identified through a stepwise identification strategy using experimental results from tests at different strain rates. The capabilities of the proposed model are demonstrated with a series of numerical simulations where complex loading conditions are applied. The model is implemented into a FE code towards performing 3D structural analyses. Abstract: In this work, a phenomenological model for thermoplastic polymers involving several mechanisms is proposed. The constitutive equations lie within the framework of thermodynamics and account for both viscoelasticty, viscoplasticity and ductile damage. An implicit numerical scheme utilizing the "return mapping algorithm" is provided along with the formulation of the tangent operator. The parameters of the developed model are experimentally identified through a gradient-based inverse method using three strain-controlled configurations. The model validation is achieved by comparing numerical results with experimental data obtained on a cyclic loading configuration test. Finally, the capabilities of the proposed model are demonstrated with a series of numerical simulations where complex cyclic and non-proportional loading conditions are applied as well as with a structural FE application.