Design of hollow and concrete filled steel and stainless steel tubular columns for transverse impact loads

The behaviour of hollow and concrete filled thin-walled steel tubular members subjected to transverse impact was previously investigated experimentally and theoretically. The members were restrained axially and rotationally at their ends. In this paper the study is extended to investigate nominally identically sized stainless steel tubes, tested experimentally under the same conditions. Comparisons between the performance of the two materials are made. Both the steel and stainless steel tubular members, hollow and concrete filled, are then modelled numerically. The FE models are validated against the experiments, and subsequently extended to investigate the general behaviour of such members when used as columns or other axially load bearing structures. The influences of axial pre-load, rotational restraint at the member ends, axial restraint, metal material properties and concrete filling, are investigated. In particular, their effect on the capacity of the members to absorb transverse impact energy. A general design procedure for metal tubular members with or without concrete filling subjected to transverse impact is developed, in a format aligned with current static structural steel specifications.

► Concrete filling of tubular metal columns has little benefit for impact energy absorption.
► Stainless steel provides significant energy absorption benefits over steel.
► Axial restraint provides the most significant contribution to energy absorption capability.
► The transverse energy capacity may be determined from the design model presented.