Search

The carbon fiber/epoxy resin composites with different stitch density were manufactured using modified lock stitching and vacuum assisted resin infusion (VARI) molding process. The influence of stitch space and stitch pitch on mechanical properties of the composites was investigated. The optimum stitch density was obtained. The results show that with increasing stitch space, both tensile and flexural properties enhance and interlaminar shear strength increases first and then decreases. With the increase of stitch pitch, both tensile and flexural properties exhibit an increasing trend. The stitched composites have the optimum integrated mechanical properties when the stitch density is 5 mm×8 mm. Their tensile strength, tensile modulus, flexural strength and flexural modulus reduce by 13.3%, 12.7%, 23.0% and 25.2%, respectively, whereas the interlaminar shear strength increases by 11.3% compared to the unstitched composites.

In this study, a novel type of composite explosive was prepared by adding titanium fiber into the RDX explosive. The effects of the content of titanium fiber on the performance of the RDX explosive were systematically studied, and the optimal concentration was obtained by comparing its performances with the RDX explosive. Underwater explosion experiments showed the optimal concentration was 15 mass%, in which the value of specific bubble energy, as well as total energy was acquired the maximum. Especially, the energy density of composite explosive with 10 mass% titanium fiber was 10.64 kJ·cm−3, compared with aluminum fiber explosive, which was increased by 17.96%. Meanwhile, results of the MTS809 machine indicated that the optimal concentration was 19.16 volume%, in which the ultimate stress increased by 175%, and critical strain increased by 393%. Additionally, better mechanical properties ensured process safety in the course of transportation and storage of explosives. Therefore, titanium fiber could be a potential energetic additive and played double roles in improving the properties of the RDX explosive significantly including detonation performances and anti-pressure ability. [ABSTRACT FROM AUTHOR]