MECHANICAL BEHAVIOR OF SILICA NANOPARTICLE-IMPREGNATED KEVLAR FABRICS

This study presents the development of a constitutive model for in-plane mechanical behavior of five styles of plain woven Kevlar fabrics impregnated with silica nanoparticles. The neat fabrics differed in fiber type, yarn count, denier, weave tightness and strength, and varying proportions (4, 8, 16 and 24% by weight) of nanoparticles were added to enhance the mechanical properties of the fabric. It was found that fabrics impregnated with nanoparticles exhibit significant improvement in shear stiffness and a slight increase in tensile stiffness along the yarn directions over their neat counterparts. A constitutive model was developed to characterize the nonlinear anisotropic properties of nanoparticle-impregnated fabrics undergoing large shear deformation. The parameters for the model were determined based on uniaxial (along yarn directions) and 45 degrees off-axis tension tests. This model was incorporated in the commercial FEA software ABAQUS through a user-defined material subroutine to simulate various load cases.