The Response of Sandwich Panels Made of Thin-Walled Tubes Subjected to Axial Load

Abstract

This paper presents the results of experimental and numerical work on the response of sandwich panels made of thin-walled tubes and mild steel plates to axial loading. The core of the sandwich panels consists of mild-steel square tubes, 20×20×0.9 mm in cross-section, in three different layouts comprising of four or five or nine tubes, (panels A, B and C respectively). Three tube configurations are investigated, as–received tubes, tubes with circular cut-out on opposite sides, and tubes with dents on opposite sides. The imperfections are located at the mid-section of the tube. The outer skin of the sandwich panel is 150×150×10 mm in cross-section and non-deformable. Quasi-static tests carried out on two and three tubes laid out in parallel between the skin indicate that the axial forces is a multiple of the axial force of a single tube, as expected. Consequently, the sandwich panel with the nine tubes deforms less than the sandwich panels with five and four tubes when subjected to similar impact energy. Triggers in the tubes improve the collapse mode of the sandwich panels. The Finite Element package ABAQUS/Explicit v6.7 is used to construct a ¼ symmetry model using shell elements to simulate the response of the sandwich panels to dynamic axial load. The Finite element simulations, validated using high speed photography footage, show good correlations with experiments.