Bearing strength of interference-fit pin joined glass fiber reinforced plastic composites

Abstract

Glass fiber reinforced plastic structures are mostly used in mid-sized marine vessels due to high strength and stiffness to weight ratio, corrosion resistance, and total life cost reductions. Mechanical joints using metallic bolts, screws, and pins are commonly used for joining thick glass fiber reinforced plastic laminates. Interference-fit pin connections provide beneficial effects such as fatigue enhancement and/or prevention of moisture intrusion to the fiber reinforced composites. This numerical and experimental study aims to investigate the effect of interference-fit on the bearing stiffness and strength of pin joined glass fiber reinforced plastic. The stress and strain distributions have been investigated for bearing loading through experiments as well as a nonlinear three dimensional finite element analysis. The quasi-static properties of the pin-loaded composites with interference-fit (0.6% and 1%) are compared with the samples with transition-fit (0% of interference-fit). The radial and the tangential strains on the vicinity of the hole obtained from the FE simulation were verified with the experimental results. The radial strains on the interference-fit pin joined glass fiber reinforced plastic coupons are lower than those on the transition-fit pin joined glass fiber reinforced plastic coupons at the consistent pin displacement, resulting in enhancement of the joint stiffness per unit bearing area by interference-fit.

Bearing damage characteristics of countersunk thin-ply/thick-ply laminated joints using an interference fit bolt

“…To improve the strength, fatigue life, and sealing performance of composite bolt connection structure, changing the load delivery state between composite components [5,[17][18][19], the interference-t jointing method is adopted for composite structures. The interference t creates a closer contact between the fastener and the composite hole wall, which induces a more uniform compression around the hole in the circumferential direction [20] and contributes to the load-bearing strength of the joint [21]. However, the size of interference should not be increased blindly for conventional ply laminates [19].…”