Mode I fracture toughness of CFRP as a function of temperature and strain rate

Composite structures currently used in the automotive industry must meet strict requirements for safety reasons. They need to maintain strength under varied temperatures and strain rates, including impact. It is therefore critical to fully understand the impact behaviour of composites. This work presents experimental results regarding the influence of a range of temperature and strain rates on the fracture energy in mode I, G(IC), of carbon fibre reinforced plastic plates. To determine G(IC) as a function of temperature and strain rate, double cantilever beam specimens were tested at 20, 80 and -30 degrees C, with strain rates of 0.2 and 11 s(-1). A complementary numerical study was performed with the aim of predicting strength using the measured values. This work has demonstrated a significant influence of the strain rate and temperature on G(IC) of the composite materials, with higher strain rates and lower temperatures causing a decrease in the G(IC) values.