Recently, the strengthening of steel structures using carbon fibre reinforced polymer has become more attractive for designers due to the advantages of high strength-to-weight ratio and superior environmental durability. Significant research has been performed on the behaviour of CFRP strengthened steel members under static loads. Dynamic behaviour, and in particular impact loading, of CFRP strengthened steelwork has been scarcely studied. In practice, steelwork could be subjected to impact from different events such as road vehicle or ship collisions, and impact by flying debris after an explosion etc.

This study discusses the numerical investigation of the effectiveness of CFRP sheets in strengthening square hollow section (SHS) steel columns under transverse impact loads. The study was conducted using the finite element (FE) programme ABAQUS 6.13. The proposed three-dimensional FE model was validated using existing experimental results. The strain hardening and strain rate effects were accounted for in this model using classical metal plasticity and Cowper Symonds model respectively, while the CFRP and adhesive material were modelled using the elastic lamina and traction separation model respectively. The effect of different parameters have been investigated in this study such as the compression load level, boundary conditions and CFRP configurations. It has been found that the CFRP can minimise column displacement for different values depending on the above parameters.