MULTI SCALE MODELING OF CONTINUOUS ARAMID FIBER REINFORCED POLYMER MATRIX COMPOSITES USED IN BALLISTIC PROTECTION APPLICATIONS

摘要

This work addresses the problem of multi length scale modeling of polymer matrix composites reinforced with high specific strength, high specific stiffness continuous aramid fibers. These composite materials are commonly used in various light weight protective systems the main requirement of which is a high level of penetration resistance against high kinetic energy projectiles (e.g. bullets, exploded mine propelled soil ejecta, fragments of improvised explosive devices, turbine blades, etc.). Within the proposed multi length scale modeling approach, the following distinct length scales have been identified and their respective mechanical constitutive relations derived and parameterized: (a) molecular chain; (b) fibril; (c) fiber; (d) yarn; (e) fabric/ply; (f) single lamina; (g) stacked lamina; and (h) laminate. In addition, issues related to identification of the type and the extent of data generated at a finer length scale to the adjacent coarser length scale, as well as seamless integration of different length scales into a unified material model, are addressed. Finally, results are presented pertaining to the implementation of the multi scale material model into a transient, nonlinear dynamics/finite element analysis of a few simplified ballistic impact scenarios.