Impact Perforation of aluminum Cymat Foam

Ibrahim Elnasri,Han Zhao,E Buzaud,E Cadoni,H Couque,A Cosculluela

doi:10.1051/epjconf/201818301003

Abstract

The behavior of aluminum Cymat foam under impact perforation loading was studied using experiments and simulations. Measurements at 40 m/s were performed with an inverse perforation setup using a Split Hopkinson Pressure Bars system. Such measurement is missing in a classical free-flying penetrator–immobile–target scheme under impact loading and makes it possible to directly compare impact the perforation force–displacement curves with the static ones. Compared with quasi-static test perforation forces obtained under the same geometry and clamping system, a significantly enhanced perforation force was found under impact loading. Numerical simulations of the perforation test were developed using LS-DYNAfinite element code to provide the local information necessary to understand the unexpected enhancement in perforation force. The shock effect was found to be responsible for enhancement of the perforation force and revealed that the honeycomb model with appropriate tensile failure criteria was more suitable for model perforation of the foam than the Deshpande and Fleck model with volumetric failure strain criteria

Highlights

The impact behaviour of cellular material have gained scientific interest recently because of their excellent properties such as specific resistances and high specific energy absorption capacities
Behaviour laws are implemented in LS-DYNA code to model the foam behaviour under impact .To choose which constitutive law best models the foams under impact perforation, we studied the honeycomb and Deshpande and Fleck models
Impact perforation tests were performed using an inverse perforation testing technique with a long, thin instrumented Hopkinson Bar. Such a measurement is missing in a classical free-flyingpenetrator–immobile-target scheme under impact loading and makes it possible to directly compare the impact perforation-force–displacement curves with the static ones

Summary

Introduction

The impact behaviour of cellular material (foam, honeycomb, hollow spheres) have gained scientific interest recently because of their excellent properties such as specific resistances and high specific energy absorption capacities. The static indentation and penetration properties of metal foams have been examined by Olurin et al [1] and Andrews et al [2]. These studies determined that plastic deformation was concentrated in the region directly underneath the penetrator. Common penetration tests at lower velocity (

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Results

Conclusion