Characterisation of resin transfer moulded composite laminates under high rate tension, compression and shear loading

The strain rate dependency of carbon fibre reinforced plastic (CFRP) laminate manufactured in a resin transfer moulding (RTM) process was investigated up to strain rates of 102 s(-1). High-speed video imaging in combination with digital image correlation analysis (DIC) and high-speed infrared cameras were applied to evaluate the tests. Specimens were specifically designed for tests at high loading rates. Periodic strain localisations were observed. Thus, multiple fractures occurred at the highest strain rate. Considerable strain rate dependence could be identified. The stress strain curves, and in the case of 90° tension and compression also the strain to fracture exhibited a moderate rise with increasing strain rate. High rate shear tests at ± 45° loading direction with large, localised deformations up to failure showed reduced hardening compared to quasi-static tests, probably caused by adiabatic heating. A local temperature rise of about 50 K was determined by high-speed infrared measurements.