Pultruded GFRP double-lap single-bolt tension joints - temperature effects on mean and characteristic failure stresses and knock-down factors

摘要

Details are presented of the fabrication and testing of five groups of twenty-four nominally identical double-lap single-bolt tension joints in pultruded glass fibre reinforced polymer (GFRP) composite plate. All of the joints had the same nominal width (W) to hole to diameter (D) ratio, but each of the five groups had a different end distance (E) to diameter ratio. Each group of twenty-four joints was divided into four sub-groups of six joints, which were tested at four temperatures. Tensile loads and overall extensions at failure and failure modes were recorded for each joint test. The test data was used to produce graphs of mean and characteristic failure stresses, as well as approximate mean and characteristic failure strains. The former data were used in conjunction with mean and characteristic failure stresses of the virgin GFRP plate to provide tensile knock-down factors for the bolted joints for five joint geometries and four test temperatures. The knock-down factors are potentially useful for preliminary joint design.