Lateral impact behaviors of concrete-filled double-steel tube with corrugated steel tube member(s)

Abstract

Concrete-corrugated steel tube (CST) composites have been widely adopted in engineering practices due to their superior ductility and energy dissipation capabilities. Given the potential exposure of these structural members to extreme loads such as impact loads during their service life, understanding their impact behaviors is essential. This paper presents experimental and numerical investigations on the lateral impact behaviors of concrete-filled double-steel tube (CFDST) with CST member(s). For comparison, six specimens were prepared and tested, including one normal steel tube, one CST, one traditional CFDST, and three CFDSTs with one or two CSTs. The lateral impact behaviors in terms of failure modes, displacement responses, impact forces, energy absorption and strains were studied and compared. It was found that CFDST with an outer CST had a higher recovery rate, a longer plateau phase of impact force, and exhibited more ductile behavior under impact compared to other specimens. Finite element models were also developed and validated by the test results. Based on the validated numerical models, the deformation mechanism of CST, axial stress, interaction between the steel tube and concrete, sectional bending moment, and energy absorption capacity were further examined.