Ballistic Impact Experiments and Quantitative Assessments of Mesoscale Damage Modes in a Single-Layer Woven Composite
In this work, we investigated the mesoscale impact and perforation damage of a single layer, woven composite target transversely impacted below and above the ballistic limit by a rigid projectile sized on the order of a tow width. To visualize mesoscale impact damage in woven composites, a thin translucent composite target was used, which provided access to both impact and back-face surfaces. High-resolution photography was used to visualize mesoscale damage, and impact and residual velocity data relative to the location of projectile impact on weaving architecture were quantified. It was found that impact on a tow-tow crossover requires more energy to perforate than impact on a matrix-rich interstitial site or on adjacent, parallel tows. Mesoscale damage in thin, woven composites was characterized for impact velocities below and above the ballistic limit. Four mesoscale damage modes were identified: transverse tow cracks, tow-tow delamination, 45° matrix cracks, and punch- shear. These damage modes were observed both on the surface and inside the composites. High-resolution images of these damage modes were quantified in digital damage maps whereby the output of color intensity correlated with the quantity and type of material damage. Digital maps generated for select specimens revealed characteristic damage patterns in woven fabric composites including a diamond pattern in matrix cracking and a cross pattern in tow–tow delamination. It was found that the greatest extent and quantity of mesoscale damage occurs for impact velocity just below the ballistic limit.
KeywordsTransverse crack Delamination Mesoscale Damage Impact
Research was sponsored by the U.S. Army Research Laboratory and was accomplished under Cooperative Agreement Number W911NF-12-2-0022. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the U.S. Army Research Laboratory or the U.S. Government. Thanks to Molla Ali of University of Delaware, Center for Composite Materials for help with material characterization. Thanks to Zuhal Onuk, Bridgit Kioko, Oreoluwa Adesina, and Carisse Lansiquot of Morgan State University for help with MATLAB scripting and damage counting. Thanks to Nebiyou Getinet and Jian Yu of the U.S. Army Research Laboratory for help with conducting ballistic experiments.
- 6.Bonyi, E., et al.: Assessment and quantification of ballistic impact damage of a single-layer woven fabric composite. Int. J. Damage Mech. (2018)Google Scholar
- 8.Haque, B.Z., Gillespie Jr., J.W.: Penetration and Perforation of Composite Structures. Mech. Eng. Res. J. 9(March), 37–42 (2013)Google Scholar
- 10.Military Test Method Standard MIL-STD-662F, V50 Ballistic Test for Armor, DOD, 1997Google Scholar
- 13.Rakhmatulin, K.H.A.: Normal impact at a varying velocity on a flexible fiber (in Russian). Uchenye Zap. Moskovosk gos Univ. 4, 154 (1951)Google Scholar
- 14.Rakhmatulin, K.H.A.: Normal impact on a flexible fiber by a body of given shape (in Russian). Prikl Mat Mekh. 16, 23–24 (1952)Google Scholar
- 15.Smith, J.C., McCracking, F.L., Schiefer, H.F.: Stress-strain relationships in yarns subjected to rapid impact loading. Part V: wave propagation in long textile yarns impacted transversely. J. Res. Natl. Bur. Stand. (1934). 60(5), 701–708 (1955)Google Scholar
- 19.Lambert, J.P., Jonas, G.H.: Towards standardization in terminal ballistics testing: velocity representation. BRL-R-1852, Aberdeen Proving Ground, MD (1976)Google Scholar