Defense Presentation

Current Frontier in Ceramic Armor

John WaldronMechanical Engineering, Villanova

University

Why ceramics in armor? Materials used in ceramic armor

◦ Al2O3, B4C, SiC Current Applications

Use of Ceramics in Armor

IBD-Deisenroth Engineering

Ballistic Impact

N.V. David, et al September 2009

Relevant Material Properties

P.G. Karandilar, et. Al 2008

Numerical/Computational Research Ballistics Research Biomimetic Research Comparisons Future Work

Current Research

Dynamics of Ballistic Protection◦ Formations of cracks

and damage zones◦ Changes in

microstructure◦ Phase Transformations

Predicative Methods ◦ Creating New

Algorithms [Fernandez]

◦ Using Established Damage Methods [Feli]

Numerical Methods

Boron Carbide Fracture Zone

P.G. Karandilar, 2008

Johnson-Holmquist Model Prevailing Damage Model

Large Deformation and Damage Evolution

Contains Material Constants

Intact Material Strength: 𝜎𝑖∗= 𝜎𝐻𝐸𝐿𝐴(𝑃∗+ 𝑇∗)𝑁 (1+ 𝐶ln𝜀ሶ) Fractured Material Strength: 𝜎𝑓∗= 𝜎𝐻𝐸𝐿𝐵(𝑃∗)𝑁 (1+ 𝐶ln𝜀ሶ) Current Material Strength: 𝜎∗= 𝜎𝑖∗− 𝐷(𝜎𝑖∗− 𝜎𝑓∗)

Damage Increment: 𝐷= σ △𝜀𝑝𝜀𝑓+ 1 3ൗ�𝐺(𝜎𝑖∗− 𝜎𝑓∗) Feli, 2011

Numerical Simulation

Fernandez, 2011 Feli, 2011

Tests Current Materials Involves Projectiles Currently Used in Combat Can Determine Applications of Certain Ceramic

Armors [Medvedovski]

Ballistics Performance Research

Medvedovski, 2010

Medvedovski, 2010

Dinosaur Eel [polypterus senegalus]

Composite Layers Exclusive Deformation

Mechanisms

Biomimetic Research

Bruet, B. J. F et al 2008

Numerical Method: Most Precise

Ballistics Performance Method: Most Practical

Biomimetic Research: Alternative Solutions

Future Work: Tailoring Microstructure

Comparisons

Bruet, B. J. F et al 2008, “Materials Design Principles of Ancient Fish Armour,” Nature Materials, Volume 7, pp. 748–756.

D. Fernandez-Fdz, R. Zaera, J. Fernandez-Saez, “A constitutive equation for ceramic materials used in lightweight armors.” Computers and Structures Volume 89, 2011 2316-2324

Eugene Medvedovski, “Ballistic performance of armour ceramics: Influence of design and structure. Part 1.” Ceramics International Volume 36, 2010. 2103-2115

References

IBD Deisenroth Engineering, “Breakthrough in Material Development for Ballistic Protection” February 16, 2011http://www.ibd-deisenroth-engineering.de/news.html

N.V. David, et al “Ballistic Resistant Body Armor: Contemporary and Prospective Materials and Related Protection Mechanisms.” Applied Mechanics Reviews Volume 62. September 2009

P.G. Karandilar, et. al “A Review of Ceramics for Armor Applications” Advances in Ceramic Armor IV Ceramic Engineering and Science Proceedings Volume 29, Issue 6, 2008 163-173

S. Feli, M.R. Asgari, “Finite Element Simulation of ceramic/composite armor under ballistic impact” Composites: Part B Volume 42, 2011 771-780

References