| Summary: | 博士 === 國防大學理工學院 === 國防科學研究所 === 98 === The purpose of this thesis is to investigate ballistic performance for various texture fabrics. Five different texture aramid fabrics, including satin, twill, plain, were produced, and then the strain-time curves were obtained through compression test. The suitable visco-elastic model for each fabric was also formulated and the coefficient of visco-elastic model of each fabric was calculated, by using curve-fitting approach. Afterward, the relationship between ballistic capability and fabric visco-elastic model was proposed, through the comparison of ballistic test and visco-elastic parameters of the model. The ballistic behavior of different fabrics was further disclosed.
The weaving fabrics presents similar behavior to Kelvin standard linear solid model, and UD structure fabrics basically follow Power law model, as indicated in strain-time curve analysis. According to ballistic test, it is found that higher fiber density improves the bullet contact and capture possibility. The V50 value of UD structure linearly increases with laminating layers increases. In contrast, plain fabric presents higher V50 than UD ones when it is thin, and dramatically climbs to a steady level, lower V50 than UD ones, with laminating layer increases.
Oblique impact behavior was also studied in the thesis. The bullet sliding occurs as impact angel greater than 150, due to delamination defect in UD structure. Short-distance bullet sliding was observed in weaving fabrics, because the bullet was resisted by weaved intersection point. This high resistance induces ricocheting as the impact angle greater than 450 in weaving fabrics, while the UD structure presents bullet sliding until the impact angle greater than 600. Overall, all of fabrics show the highest impacted depth at 300-450 impact angles.
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