Effect of channel cracks on fiber’s fracture in one-component material with unidirectional fibrous structure

Abstract

Materials obtained by pressing a fiber bundle at plastic deformation possess pore channels with cross-sections in the form of hypocycloids the size of which depends on the pressing regime. These channels are equivalent to channel cracks (CC) at failure. A three-dimensional analysis of extension of the elastic and inelastic shear area at the interface of the cracked fiber in the bundle of undamaged fibers under tension is performed. The fiber stacking in the bundle is hexagonal. The fiber cross-sections are regular hexagons. The effect of CC size on the stress intensity factor (SIF), the crack opening displacement (COD) in the fiber, the energy dissipation (ED) at the inelastic shear at the fiber interface and the length of the interface with the non-zero shear stresses (LIS) are investigated. It is found that the ED at the interface of the cracked fiber, SIF and COD for the crack in the fiber and LIS are determined by the product of the interface cohesive strength and the contact width between fibers. Full text download