Experimental Study on the Dynamic Response and Damage State of Steel Square Tubular Structural Components by Near-field Explosions

In order to explore the dynamic response and damage state of the steel square tubular structural component under blast-loading, A few experiments of near-field explosions are conducted respectively on five steel square tubes, Among them, two are hollow, one is wrapped with glass fiber-reinforced plastic (GFRP) on the front surface, and others are the one being infilled with C30 and the other with C70 concrete. It can be concluded from the analysis on the deformation and strain of the tubes that, at the same explosive mass, when the standoff distance of the steel square tube is lengthened from 48.5 mm to 68.5 mm, the maximal depth of deformation on the front surface is lessened by 37.5%, deflection by 42.1% and residual strain by 66.7%. As wrapped with GFRP, the maximal deformation is reduced by 17.0%, deflection by 30.8% and the residual strain is decreased by 69.5% respectively, the approach by wrapped with GFRP on the tube can improve the performance of blast resistance. While being infilled with concrete, the deformation of the tube is greatly reduced. Moreover, the deformation is decreased with the increment of the compressive strength of the concrete. Specifically, when the components are infilled with C30 and C70 respectively, the residual strains are decreased by 91.3% and 69.1% respectively.