This paper presents an optimization method and results on a material model of Kevlar 49 fabric that was implemented in LS-DYNA through a user defined material subroutine (UMAT). Both the shear properties of the fabric and the parameters used in Cowper-Symonds (CS) model that accounts for strain rate effect on material properties were optimized to achieve close match between the FE simulations and experimental data. Two different modeling configurations, i.e. single FE layer (SL) and multiple FE layers (ML) were used to simulate the ballistic tests conducted at NASA-GRC. The results show that the single layer model is computationally efficient and predicts the ballistic tests with less error than the multi-layer model, while the latter is able to consider the friction between fabric layers.