Experimental and numerical investigation of CFRP strengthened steel beams under impact load

Use of carbon fibre reinforced polymer (CFRP) strengthening of structural elements has been gaining increased traction over the past few years. Although some research has been carried out on the behaviour of CFRP strengthened steelwork under static and fatigue loads, no single study exists which experimentally captures the response of CFRP strengthened steel beams under impact load. In the present study, a series of tests was conducted to gain insight into the effect of impact load on such beams. The parameters examined in the experiments were namely the thickness and length of the CFRP layers. The impact test was performed by dropping a 91 kg impactor with a velocity of 4.43 m/sec. A finite element analysis (FEA) model was developed in which the bond between CFRP and steel, strain rate effects for steel, and failure of both CFRP and adhesive material were included. Comparing the test data with corresponding FE results confirmed a high level of accuracy of the predicted results. A series of detailed analyses on the impact behaviour of CFRP strengthened steel beams was performed using the validated FE model to provide further insight.