Effect of loading rate on the compressive behaviour of twill woven carbon/polyamide laminate

Abstract

This paper presents the experimental investigation on the strain rate effect on the longitudinal compressive behaviour of 2×2 twill woven carbon fibre reinforced polyamide 66. An original easy-to-use specific testing fixture was developed to perform material characterization using an electromechanical machine and a Split Hopkinson Pressure Bar (SHPB) system. The set-up was completed with a high speed camera used to monitor the deformation and failure process and to allow the strain field visualization via Digital Image Correlation (DIC). A particular attention was paid to the validity of the experiments: failure in the test specimen gauge section, stress equilibrium and strain homogeneity. The same testing fixture and specimen geometry were implemented from 1.5×10−5s−1 to 700 s−1. The results comparison shows a positive strain rate effect with a 60% increase in the longitudinal compressive failure stress.