Experimental analysis of diamond and regular tubular braided composites using three-dimensional digital image correlation

Braided composites can be manufactured in a variety of braid patterns: Diamond (1/1), Regular (2/2), and Hercules (3/3) and with longitudinal reinforcement (Triaxial). The complex strain fields, which could help reveal phenomenological behavior of braids, have not been experimentally assessed. As such, the objectives of this article were to investigate the effect of braid pattern (Diamond, Regular), braid angle (35°, 45°, 55°), and load (tensile, torsion) on the strain field and elastic properties (longitudinal and shear moduli) using a three-dimensional digital image correlation method. The methodology presented in this manuscript will be used to validate a new analytical model, which predicts the elastic properties of tubular braided of both varying braid type and braid angle.