Ballistic Limit Estimation Approaches for Ballistic Resistance Assessment

  • Beya Tahenti Military Academy of Fondouk Jedid, Nabeul
  • Frederik Coghe Royal Military Academy, Brussels
  • Rachid Nasri National Engineering School of Tunis, University Tunis El Manar
Keywords: Ballistic resistance, Ballistic limit, Normal law, Perforation probability

Abstract

The armour technologist conducts ballistic impact testing either for evaluating armour materials and systems or for studying material’s defeating mechanism. Most standards make use of the ballistic limit velocity for ballistic assessment. This is the bullet impact velocity that leads to the protection perforation in 50 per cent of the cases. Various models have been emerged to estimate this key metric. The present article summarises the popular models developed for ballistic limit estimation. An attempt is made to point out models’ strength and weakness. First, the experimental set-up used for that goal is displayed. Next, a concise overview of ballistic limit estimation methods is presented. Lastly, a discussion is dedicated to model’s comparison and analysis. This literature survey reveals that the main drawback of already existing methods is that they are purely statistical. Moreover, existing methods are based on the normality assumption of perforation velocities which tends from -infinity to infinity. The main conclusion of this survey is that the presented methods offer a comparable accuracy in estimating the ballistic limit velocity. However, a given variability is remarked when extreme values estimation is of interest, impact velocities leading to low and high perforation probability. Finally, existing models’ performances decay with the reduction of the experimental sample size which represent a constraining requirement in ballistic resistance assessment.

Author Biographies

Beya Tahenti, Military Academy of Fondouk Jedid, Nabeul

Dr Beya Tahenti received a joint PhD in mechanical science and engineering from the National Engineering school of Tunis and the Royal Military Academy of Belgium. Her main research scope is terminal ballistics and related fields like material and mechanical science, fracture mechanics and metallurgy. Presently she works on teaching ballistics and weapon systems.

Frederik Coghe, Royal Military Academy, Brussels

Dr Frederik Coghe received a joint PhD in material science and engineering from the University of Ghent and the Royal Military Academy of Belgium. His research interests cover material characterisation, engineering and testing, metallurgy, ballistic impact, and fracture mechanics.

Rachid Nasri, National Engineering School of Tunis, University Tunis El Manar

Prof. Rachid Nasri is a full professor at the National Engineering School of Tunis in the mechanical engineering department. He is working on mechanical engineering, kinematics and dynamic analysis with a specialised interest in mechanical vibrations and finite element methods. He is actively involved in teaching and research. He is a reference consultant in his area.

Published
2020-02-10
How to Cite
Tahenti, B., Coghe, F., & Nasri, R. (2020). Ballistic Limit Estimation Approaches for Ballistic Resistance Assessment. Defence Science Journal, 70(1), 82-89. https://doi.org/10.14429/dsj.70.14122
Section
Materials Science & Metallurgy