# Tensile Properties and Mechanism of Carbon Fiber Triaxial Woven Fabric Composites

## TL;DR

This study examines how manufacturing methods affect the tensile strength and failure mechanisms of carbon fiber triaxial woven composites.

## Contribution

The study reveals the impact of yarn spreading on improving tensile strength and reducing failure mechanisms in triaxial woven composites.

## Key findings

- Yarn spreading increased tensile load by over 30% in carbon fiber triaxial woven composites.
- Acoustic emission monitoring showed a significant reduction in resin and fiber/matrix debonding after yarn spreading.
- Digital image correlation revealed decreased fiber strain at interweaving points after yarn spreading.

## Abstract

The manufacturing methodologies for carbon fiber triaxial woven fabric composites demonstrate significant variability, resulting in the failure mechanisms under tensile loading conditions, and the fundamental role of interweaving points remains unclear. Moreover, the mechanisms of destruction under tensile loads have not been sufficiently studied. In this study, the resin transfer molding and resin film infusion were selected to fabricate carbon fiber triaxial woven fabric composites, with a specific focus on their effects on the tensile properties of carbon fiber triaxial woven composites. Compared with ordinary materials, the tensile load of carbon fiber triaxial woven fabric composites after yarn spreading has increased by more than 30%. The strength can reach 1133 MPa after yarn spreading of 3k carbon fiber, which was 39% higher than the original. Furthermore, acoustic emission monitoring shows that the counts of acoustic signals in the first half dropped from 10,000 to around 3000, mostly due to the reduction of resin and fiber/matrix debonding. The digital image correlation provided full-field strain analysis, which proved that the strain of the fibers at the interweaving points decreased significantly during the stretching process after yarn spreading.