Mechanical characterisation of the dynamic tensile properties of CFRP sheet and adhesive at medium strain rates

Unidirectional normal modulus CFRP (CF130) and Araldite 420 and MBrace saturant adhesives are now commonly used to strengthen steel and concrete structures. However, there is a lack of understanding regarding their mechanical properties under dynamic tensile loads. This paper focuses on the experimental determination of the tensile mechanical properties of such materials at quasi-static and intermediate strain rates. A drop-mass rig and an impact Instron testing machine were utilised to conduct impact tests of CFRP and epoxy. It was found that the tensile properties of CFRP and the two adhesives are strain rate-dependent, even though their general trends and percentages of enhancement differ. Considerable changes in the failure patterns of CFRP and both adhesives are observed. Empirical equations in terms of strain rates are proposed to estimate the tensile properties of CFRP and both adhesives at any strain rate within the range considered.