Material Modeling and Dynamic-Response Analysis of Resin-starved Cross-collimated Compliant Composites

摘要

A continuum-level material model is developed for a class of compliant composite materials consisting of cross-collimated high-performance polymeric filaments, embedded into a low-content porous polymeric matrix. During development of the material model, atomic-level simulations were used to infer the matrix/filament de-bonding behavior, while meso-scale unit-cell based finite element analyses were employed to obtain the associated material-damage evolution law. Open-literature mechanical property data for the constituent materials and the available processing/microstructure information are next used to calibrate the model for the case of a Kraton-matrix compliant composite reinforced with 0790° cross-collimated ultra-high molecular weight polyethylene (UHMWPE) filaments. The model is then integrated into a user-material subroutine and used in a series of transient non-linear dynamics analyses of transverse impact of several composite laminates of different thicknesses with two types of projectiles. The computational results are next compared with their experimental counterparts to provide a first-order validation of the present material model. This comparison revealed reasonably good qualitative agreement between the experimental and the corresponding computational results; specifically, (a) the ability of the simulated composite laminates to reproduce the experimental results of projectile arrest when having different initial velocities; (b) the post-mortem spatial distribution of damage within the laminates; (c) the temporal evolution of composite armor laminate back-face bulging and delamination; and (d) the existence of three distinct penetration stages: (ⅰ) an initial stage dominated by shearing/cutting of the filaments directly impacted by the projectile; (ⅱ) an intermediate stage characterized by pronounced filament/matrix de-bonding/decohesion in the composite-panel regions adjacent to the projectile; and (ⅲ) the final stage associated with extensive and large-scale delamination and bulging of the composite panel back-face.