Structural behavior of steel-concrete-steel and steel-ultra-high-performance-concrete-steel composite panels subjected to near-field blast load

In this paper, field blast tests and numerical simulations were conducted to investigate the structural behavior of steel-concrete-steel (SCS) composite panels with shear studs and tie bars as connectors under near-field blast load. Four specimens, including two SCS panels, one steel-ultra-high-performance-concrete-steel (S-UHPC-S) and one normal reinforced concrete (NRC) panel, were fabricated with the same geometric dimensions and tested in the field with cylinder charges under the scaled distances of 0.4 m/kg1/3 and 0.6 m/kg1/3. Finite element models with the implementation of multi-material Arbitary-Lagrangian-Eulerian (MM-ALE) algorithm were built to demonstrate the spatial distribution of shock waves with adequate validation, and the calculated blast load was then simplified and used to compute the dynamic response and the failure mode of SCS and S-UHPC-S panels. After validation of the numerical models, the parametric studies were conducted to investigate the effects of thickness and yield strength of faceplates, ratio of shear connector spacing to the faceplate thickness, section depth of the panels and scaled distance on the structural behavior of SCS and S-UHPC-S panels against near-field blast load. The results indicate that the structural response of SCS and S-UHPC-S panels under the near-field blast load is dominated by global flexural response with the scaled distance (Z) ranging from 0.3 m/kg1/3 to 0.6 m/ kg1/3, but shear cracks form near the supports and local damage occurs at Z = 0.3 m/kg1/3. Replacing normal concrete core with UHPC or enlarging the section depth is an effective way to mitigate shear cracking and potential shear failure. In addition, the blast resistance of SCS panel is much superior to that of NRC panel with the same geometric dimensions and is also much greater than that of NRC panel with the similar section strength under close-in scaled distance.