Modelling impact resistance of polymer-laminated steelwork

This paper reports on the numerical simulation of a series of steel beams strengthened with carbon-fibre-reinforced polymer laminates and subject to impact loads. Non-linear finite-element analysis was conducted using a proposed model validated by way of comparison with available experimental tests. The numerical model includes the effect of strain rate for steel using the Johnson–Cook model, while for the laminate and adhesive materials the Cowper–Symonds model is used. Several possible failure modes for the strengthened member can be captured using the model such as the global steel failure, polymer rupture and debonding between steel members and polymer laminates. The numerical results show that the use of externally bonded laminates decreases mid-span deflection of strengthened beams in the series by 11%. While having the same level of impact kinetic energy, it is found that a beam struck at a lesser velocity and with a larger mass of impactor tends to have higher deflection, for both strengthened and unstrengthened cases. Additional key parameters such as laminate thickness are also investigated in this study.