Over the last 10 years, Southwest Research Institute® (SwRI®) has developed reliable mesoscale ballistic impact models for woven fabrics of Kevlar, PBO, and Dyneema and composites like Kevlar/resin, S-2 glass/SC-15 epoxy, Dyneema HB-80, and Carbon Fiber/epoxy. The key to the success of these models was a “building-block” approach with thorough testing of the individual components as well as coupons and plates. Typically, the tests performed are: ballistic tests on single yarns, tensile, compression, shear, and delamination tests on neat resin and composite specimens with different architectures, and, finally, ballistic tests of panels.
A new approach to modeling HB80 Dyneema (that can also be used for HB26, HB50, and similar) was presented last year. It captured material subtleties like: 1) Through-thickness compression tests published by Attwood [1] which was achieved by using an equation of state published in the literature, 2) The pressure dependence of the matrix strength for compression and lap shear tests as published by Chocron et al. [2], and 3) Deflection histories that it was not possible to match with the simple contact condition used in [2]. The new approach also used an original compact mesh more computationally efficient.
This talk will present the final results from this model which include a thorough validation comparing tests and computations for: 1) Ballistic limits for a range of fragment simulating projectiles and areal densities, 2) Depth of penetration, and 3) Initial deflection during ballistic impact.
References
[1] J. P. Attwood et al., “The out-of-plane compressive response of Dyneema (R) composites,” J. Mech. Phys. Solids, vol. 70, no. 1, pp. 200–226, 2014.
[2] S. Chocron et al., “Modeling Unidirectional Composites by Bundling Fibers into Strips with Experimental Determination of Shear and Compression Properties at High Pressures,” Compos. Sci. Technol., vol. 101, pp. 32–40, 2014.
