LVI and post-LVI mechanical degenerate behaviors of GFRP T-joint after seawater hydrothermal aging

This paper aims to investigate the effect of seawater hydrothermal aging on the mechanical performance of the glass fiber reinforced polymer (GFRP) T-joint, fabricated via vacuum-assisted resin infusion (VARI) process, and which is a typical structure between the primary and secondary components in a ship structure. After subjecting the samples to hydrothermal aging at varying temperatures and durations, we conducted low-velocity impact (LVI) tests followed by post-LVI tensile tests with the help of self-designed fixtures and standard testing protocols. The results reveal the mechanical responses and failure morphology of the GFRP T-joints, thereby elucidating their failure mechanisms. The results show that the seawater hydrothermal environment of either higher temperature or longer duration could accelerate the aging. Moreover, compared to conventional hydrothermal aging, the seawater hydrothermal environment significantly reduces the performance of T-joint structures in both LVI and post-LVI tests.