Dynamic intralaminar fracture toughness characterisation of unidirectional carbon fibre-reinforced polymer composites using a high-speed servo-hydraulic test set-up

Kurzfassung

This paper presents experimental investigations on the in-plane shear behaviour and intralaminar fibre-dominated fracture of UD IM7/8552 carbon-epoxy composites, loaded under quasi-static (QS) and intermediate strain rates (IR). Dynamic tensile testing is carried out using a previously proposed test methodology involving a high-speed servo-hydraulic test machine and Digital Image Correlation (DIC), with the aim of providing an alternative means to Split-Hopkinson pressure bar testing for the characterisation of similar composite materials at intermediate strain rates. Three sizes of Double-Edge Notched Tension (DENT) specimens are tested at QS and IR to obtain the mode I intralaminar fracture toughness. The results of both in-plane shear and fracture toughness tests compare well with literature data, supporting the proposed methodology. This study is a first step towards standardising a test method for measuring various mechanical properties of fibre-reinforced polymer (FRP) composites at intermediate strain rates.