Seismic Resistance of GFRP Bolted Joints with Carbon Nanotubes

摘要

Bolted joints are critical in bracing elements subjected to seismic loads. When fabricated out of glass fiber reinforced polymers (GFRP), joint capacity is limited by the shear strength of the GFRP.We hypothesize that adding multiwalled carbon nanotubes (MWCNTs) to the epoxy resin prior to fabricating GFRP elements can improve the seismic resistance of GFRP bolted joints. Linear elastic structural analysis of a structure with GFRP bracing subjected to the 1940 El Centro earthquake was conducted. GFRP joints were fabricated using neat epoxy and epoxy nanocomposite incorporating 0.5% by weight MWCNTs. Bolted GFRP joints were tested under a seismic displacement time history identified using the finite-element (FE) model. Static tension test to failure was then used to determine the joint postseismic capacity. It is shown that the seismic resistance of GFRP bolted joints incorporating MWCNTs increased by 44% compared with neat GFRP joints. Furthermore, GFRP joints incorporating MWCNTs showed a postseismic static resistance that is 250% higher than neat GFRP joints and demonstrated a tension-stiffening behavior not observed in neat GFRP joints.