Numerical investigation of CFRP strengthened RHS members under cyclic loading

Rectangular hollow section (RHS) steel members are commonly utilized in various mechanical and civil engineering applications, but they have shown to be quite vulnerable under cyclic loading. In both onshore and offshore infrastructure, steel members can be subjected to cyclic loading produced by earthquakes, currents, wind and waves. Considering multiple factors, such as design errors, the influence of environmental conditions, an increase in applied loads and material deterioration, steel members may require strengthening to withstand cyclic loadings. This study presents numerical simulations using finite element (FE) modelling techniques to analyse carbon fibre reinforced polymer (CFRP) strengthened RHS steel members subjected to cyclic loading to predict their behaviour and modes of failure. The predicted results are compared with available results from experimental tests to validate the numerical models and ensure their accuracy. Results imply that CFRP strengthened RHS steel members demonstrate enhanced cyclic performance in which the moment-rotation hysteresis behaviour, secant stiffness and the energy dissipating capacity are improved compared those in bare steel RHS members. Furthermore, the effects of section thickness, bond length of CFRP, number of CFRP layers, wrapping orientation of CFRP and elastic modulus of CFRP on the response of these structural members are also investigated through detailed parametric studies.