Micromechanical Fatigue Visco-Damage Model for Short Glass Fiber Reinforced Polyamide-66

Nicolas Despringre (1) , Yves Chemisky (1) , Gilles Robert (2) , Fodil Meraghni (1)

1 LEM3 - Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux
2 Solvay Engineering Plastics

This work presents a micromechanical fatigue damage model developed for short glass fiber reinforced PA66. It has been developed to predict the high cycle fatigue behavior of PA66/GF30. The model is based on an extended Mori-Tanaka method which includes coated inclusions, matrix viscoelasticity and the evolution of micro-scale damage. The developed model accounts for the nonlinear matrix viscoelasticity and the reinforcement orientation. The description of the damage processes is based on the experimental investigation of damage mechanisms previously performed through in-situ SEM tests and X-ray micro-computed tomography observations. Damage chronologies have been proposed involving three different processes: interface debonding/coating, matrix micro-cracking and fiber breakages. Their occurrence strongly depends on the microstructure and the relative humidity. Each damage mechanism is introduced through an evolution law coupled to local stress fields. The developed model is implemented using a UMAT subroutine. Its experimental validation is achieved under stress or strain controlled fatigue tests.

Mots clés: Polymer-matrix composites; Short glass fiber; Multi-scale modeling; Viscoelastic-Damage behavior

Domaines: Mécanique des matériaux [physics.class-ph]

Nicolas Despringre, Yves Chemisky, Gilles Robert, Fodil Meraghni. Micromechanical Fatigue Visco-Damage Model for Short Glass Fiber Reinforced Polyamide-66. TMS Middle East-Mediterranean Materials Congress on Energy and Infrastructure Systems (MEMA 2015), Jan 2015, Doha, Qatar. pp.451-459, ⟨10.1002/9781119090427.ch48⟩. ⟨hal-01207175⟩