Simplified simulation of impact bullet - stratified pack for restraining ballistic tests

Catalin Pirvu,Simona Badea,Lorena Deleanu,Traian Florian Ionescu,L Slătineanu,C.E Panait,P Kyratsis,O Dodun,A.M Mihalache,V Merticaru,M Boca,G Nagit,G Oancea,M Coteata,R Ibanescu,M.I Ripanu

doi:10.1051/matecconf/201711206023

Abstract

This paper presents a macro FEM isothermal model for simulating the impact of a 9 mm FMJ bullet on a stratified packs in order to restrain the preliminary tests for actual stratified packs made of layers of Twaron LFT SB1plus (Teijin), taking into account the friction between layers and between bullet and layers, in order to obtain the number of layers that arrest the bullet. The layers were considered as an orthotropic material, with maximum equivalent plastic strain of 0.06. The materials are modeled as bilinear isotropic with hardening. The analyzed parameter to validate the model was the number of broken layers. The average value of back face signature for a 12 layer pack was of 19.44 mm recommending it for protection level of II and IIA (NIJ Standard-0101.06-2008).

Highlights

The aim of this paper is to run a simplified simulation of the impact bullet - stratified pack for restraining one or more parameters involved in the pack testing
The simulation pointed out the total penetration for the pack with 4 layers and 7 broken layers in the pack with 8 layers; the pack with 12 layers has only 4 broken ones (Figure 8)
The model was validated as for the pack made of 8 layers, there were obtained total penetration for more than half of the fires, but there were bullets arrested between the

Summary

Introduction

The aim of this paper is to run a simplified simulation of the impact bullet - stratified pack for restraining one or more parameters involved in the pack testing. The isothermal model has 14 solid bodies: 12 identical layers considered a group of bodies (with the option multiple materials), overlapped and rigidly fixed on their contour, and 2 bodies for the bullet ( multiple materials) with bonded connections (Table 1, Figure 1). Many recent models accepted the rigid clamp on the contour [15], even if for body armor, the pack is supported on visco-elastic material. Materials are modeled as hardening bilinear isotropic. This simplifying hypothesis could be justified by the arrangement of long aramid fibers, long at four different angles (0, 90, 45, -45) [20]. After consulting the literature [21, 22], the failure criterion was the ultimate plastic strain, set for 0.05

Objectives

Results

Conclusion