Behavior of Mechanical Joints Prepared from EB Cured CFRP Nanocomposites Subjected to Hygrothermal Aging Under Bolt Preloads

In the present work, the hygrothermal aging effect was studied on the performance of bolted joints prepared from electron beam (EB) cured carbon/epoxy nanocomposites under varying bolt torques. The multiwalled carbon nanotubes (MWCNTs) at different wt.% varying from 0 to 0.5 were added into the composite laminates with 0.3 wt.% giving the maximum tensile strength. The comparison of mechanical properties was done for thermally cured, EB cured (without post curing) and EB cured (post curing) composites. For hygrothermal aging of neat and 0.3 wt.% MWCNT configurations, water absorption studies were conducted at three different water temperatures i.e., 25 °C, 45 °C, and 65 °C for 30 days, as per ASTM D5229. The mechanical strength retention of aged composite specimens were analysed. Using ASTM D5961, the bolted joint specimens were prepared to investigate the bearing response and ultimate failure loads in the composite bolted joints. The damage occurred due to hygrothermal conditions has been interpreted in the light of their morphological structures.