Experimental and numerical study of GFRP-reinforced steel tube under axial impact loads

The performance of glass fiber-reinforced epoxy resin (GFRP) reinforced thin-walled circular steel tubes under axial impact loads was studied using both numerical and experimental methods. The specimens' failure modes and the effects of steel diameter, winding angle (the angle between the axis of the tube and the tangential direction of winding fiber) and impact velocity were studied through tests. Explicit solver of ABAQUS was chosen and a VUMAT subroutine considering Hashin criterion, Puck criterion and modified Hashin criterion was written to simulate the failure and damage evolution of GFRP. Simulation results matched experiment results well. The influence of steel tube thickness and outer diameter, GFRP thickness and winding angle, specimen length and impact velocity was analyzed using finite element analysis. Predictive formulas were introduced to estimate the peak and mean impact force on specimens experiencing strength failure.