Joining pultruded FRP tubular components into space latticed shell structure - joint design and performance

The development of space latticed shell structure using fibre reinforced polymer (FRP) tubular members is a promising practice wherein the key issue is to join different components together. In this study, a bolted sleeve joint in a staggered pattern was designed for joining square tubular pultruded FRP members into the proposed system inspired by Unistrut®. The current study focuses on the joint performance under tensile loading and a total of four groups of specimen were prepared. Key parameters including bolt type (normal bolt or blind bolt), element dimensions (e.g. tube and bolt dimensions) and bolt group layouts were chosen and studied. During experiments, the failure modes, load-displacement and load-strain relationships were recorded to assess the joint performance. The test results demonstrate that a desirable ultimate load carrying capacity can be achieved by optimising element dimensions and bolt group layout when using normal bolt. Besides, when blind bolts are used, the compromise between easier fixing and joint performance must be considered.