Sandwich Panels with Polymeric Foam Cores Exposed to Blast Loading: An Experimental and Numerical Investigation

Kristoffer Aune Brekken,Aase Reyes,Magnus Langseth,Torodd Berstad,Tore Børvik

doi:10.3390/app10249061

Abstract

Sandwich panels have proven to be excellent energy absorbents. Such panels may be used as a protective structure in, for example, façades subjected to explosions. In this study, the dynamic response of sandwich structures subjected to blast loading has been investigated both experimentally and numerically, utilizing a shock tube facility. Sandwich panels made of aluminium skins and a core of extruded polystyrene (XPS) with different densities were subjected to various blast load intensities. Low-velocity impact tests on XPS samples were also conducted for validation and calibration of a viscoplastic extension of the Deshpande-Fleck crushable foam model. The experimental results revealed a significant increase in blast load mitigation for sandwich panels compared to skins without a foam core, and that the back-skin deformation and the core compression correlated with the foam density. Numerical models of the shock tube tests were created using LS-DYNA, incorporating the new viscoplastic formulation of the foam material. The numerical models were able to capture the trends observed in the experimental tests, and good quantitative agreement between the experimental and predicted responses was in general obtained. One aim of this study is to provide high-precision experimental data, combined with a validated numerical modelling strategy, that can be used in simulation-based optimisation of sandwich panels exposed to blast loading.

Highlights

Cellular materials such as honeycombs, open and closed cell foams and hollow metal spheres, have excellent characteristics as energy absorbers under extreme conditions such as blast and impact due to their ability to deform uniformly over a long stroke at an almost constant load [1]
All curves are corrected for the shock tube rigid body movement and shifted in time such that the time equals zero when the shock wave arrives at sensor S01
This is partly because the blast load is included without accounting for FSI effects, and not ideal for load level P12 and P15 have been moved to Appendix A2 to reduce the data amount presented in for an accurate prediction of the structural response

Summary

Introduction

Cellular materials such as honeycombs, open and closed cell foams and hollow metal spheres, have excellent characteristics as energy absorbers under extreme conditions such as blast and impact due to their ability to deform uniformly over a long stroke at an almost constant load [1]. The properties of such materials are governed by the cell structure topology and the intrinsic property of the constituent material, where the topology defines how the constituent material is packed in space to form a porous structure [2].

Objectives

Methods

Results

Conclusion