Static and fatigue characterization of flax fiber reinforced thermoplastic composites by acoustic emission

Abstract

Abstract The objective of this study is to investigate the mechanical behaviour and to provide a complete set of static and fatigue loading data on thermoplastic composites based on flax fiber. The manufacturing technique used for preparing the composite material samples was the liquid resin infusion. Since the inclusion of natural fiber in the polymer induces nonlinear behaviour within the structure, it is essential to proceed by an experimental approach. Firstly, static tensile tests were carried out to identify the composite mechanical properties and the damage and rupture mechanisms that occur during loading. Secondly, cyclic tensile test were realized to investigate macroscopic damage. Then, fatigue tensile behaviour was studied by evaluating the material stiffness degradation which is regularly used to identify failure criterion. The fatigue results were summarized in a S-N curve. All experimental tests were coupled with the acoustic emission technique which leads to identify the major mechanisms that contribute to damage and its kinetics of appearance.