Experimental methodology for high strain-rates tensile behaviour analysis of polymer matrix composites

Material overall mechanical behaviour varies significantly under rapid straining as compared to quasi-static loading. Analysing the damaged elastic behaviour of composite materials under dynamic loading requires theoretical tools and experimental approaches integrating the strain rate effects. This work is concerned with development and optimisation of an experimental methodology devoted to the micro and macroscopic characterisation of composites mechanical behaviour under high-speed loadings. The applied experimental procedure has been optimised in an attempt to isolate the inherent inertial disturbances attributed to the test system. The optimisation aims at minimizing the amplitude of measurements perturbation in order to give rise to homogeneous stress/strain fields within the tested specimen. Using a servo-hydraulic machine, monotonic and interrupted tensile tests were performed at different strain rates and coupled to scanning electronic microscope observations. The developed approach has been applied at strain rates up to 200 s−1 for two composite materials: SMC-R26 and a woven carbon-epoxy laminate.