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The application of woven fabrics in composites manufacturing has been increased because of their special mechanical behavior. Due to the complexity of modeling and simulation of these composites, in this research a micromechanics based analytical model has been developed to predict the elastic properties of woven fabric composites. The present model is simple to use and has a high accuracy in predicting the elastic properties of woven fabric composites. One of the most important effective factors on the modeling accuracy is utilizing a proper homogenization method. Therefore, a new homogenization method has been developed by using a laminate analogy based method for the woven fabric composites. The proposed homogenization method is a multi-scale homogenization procedure. This model divides the representative volume element to several sub-elements, in a way that the combination of the sub-elements can be considered as a laminated composite. To determine the mechanical properties of laminates, instead of using an iso-strain assumption, the assumptions of constant in-plane strains and constant out of plane stress have been considered. Then, the proposed homogenization model has been combined with a micromechanical model to propose the new micromechanical model. The applied assumptions improve the prediction of mechanical properties of woven fabrics composites, especially the out of plane elastic properties. The proposed model has been evaluated by comparing the predicted results with four available experimental results available in the literature, and the accuracy of the present model has been shown.

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Recently shear thickening fluids (STF) are applied more and more to improve the penetration resistance of fabrics. In this research, at first, the performance of the neat and STF impregnated fabric subjected to the impact of 8.7 mm diameter steel spherical projectile is investigated experimentally. Then, the numerical analysis is done to study the effective parameters such as fabric density, static and dynamic coefficients of friction between yarns and between projectile and fabric, boundary conditions and number of layers of fabric by using commercial tool LS-DYNA software. Previous studies expressed that the major factor that improves the energy absorption capacity of STF impregnated fabrics is the friction between the impact projectile, fabric, and yarns within the fabric, however here the investigations showed that in addition to the friction, the mass of added STF is effective in the results. Increasing the mass of the fabric by adding STF, is considered as the increasing density of the fabric. Empirical investigations showed that STF-impregnated fabrics exhibited a significant enhancement in penetration resistance performance as compared to neat fabric such that the projectile penetration subjected to the fabric with 44% wt STF decreased 63% compared to neat fabric. The simulation results showed that, if the STF effects just assign to increased friction, the projectile penetration decreased 43% compared to neat fabric. But if in addition to friction, the mass of the STF is considered as the effective parameter, the penetration decreased 58% which have good agreement with experimental data.