The effect of Tube-in-Tube buckling-restrained device on performance of hybrid PFRP-Aluminium space truss structure

Abstract

Due to low elastic modulus, overall buckling of slender pultruded fiber reinforced polymer (PFRP) strut is prone to occur. Hence, the Tube-in-Tube buckling restrained device (TTBRD) for PFRP tube was firstly proposed and detailly introduced. The structural effect of TTBRD was examined by compressive tests on hybrid PFRP space truss girder with and without TTBRDs. The results demonstrate that the structural bearing capacity and ductility have been greatly improved. To implement accurate structural calculation, preliminary finite element (FE) analyses were conducted at the component level. A single PFRP tube with TTBRD was separately modelled by three kinds of FE models, which adopt the concept of “surface-to-surface”, “line-to-surface” and “line-to-line” contact, respectively. The difference of the three kinds of FE models was compared and analysed. The appropriate FE models have been selected, and the behaviour of PFRP girder can then be well simulated. To further explore possible application, the verified FE model was used to simulate a large-scale 5 × 5 square-on-square space truss structure with different numbers of TTBRDs. It was demonstrated that the structural progressive buckling can be effectively prevented. Additionally, the TTBRD provides a good way for structural health monitoring of PFRP space truss structures.