Rate dependence of mode I fracture behaviour in carbon-fibre/epoxy composite laminates

摘要: Abstract The rate dependence of mode I interlaminar fracture behaviour in unidirectional carbon-fibre/epoxy composite laminates has been investigated over a wide range loading rates from quasi-static (displacement rate, δ = 0.01–500 mm min−1) to impact (δ 5–20 see−1) at room temperature. Impact tests were performed by the WIF (wedge-insert-fracture) method with SHPB (split Hopkinson pressure bar) system for accurate measurement toughness, while DCB (double-cantilever-beam) screw-driven testing machine. In present laminates, toughness decreased stepwise increasing showing distinct rate-sensitive transition region and two rate-insensitive regions above below. As consequence this characteristic, crack growth varied rate: below region, grew unstably accompanied high-speed propagation arrest; but stably continuously. This trend was well explained simple model incorporating contribution kinetic energy specimen during unstable propagation.