Effect of the meso-structure on the strain concentration of carbon-carbon composites with drilling hole

Abstract

In this work, the influence of fiber/matrix meso-structure on the strain concentration of three-dimensional (3D) reinforced carbon-carbon composites with a drilling hole is discussed by experimental and numerical ways. The full-field digital image correlation (DIC) method is adopted to obtain the strain field of the experimental specimens, and the meso-FEM model with the consistent meso-structure of the experimental specimens is established to reveal the main deformation and damage mechanism. The results show that the strain concentration appeared off the location of ±90° hole tips, which is different with homogeneous material. Furthermore, the shear bands are observed and located on the region between the cut fiber yarn and the adjacent uncut one. The peculiarities are found connecting with the meso-structure. Moreover, the damage locations obtained from the meso-model show good agreements with the experimental fracture path, thereby, the analyses are verified.