Analysis of a fiber bridged crack near a free surface in ceramic matrix composites

✍ Scribed by J.C. Lee

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 740 KB
• Volume: 37
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(90)90344-g

✦ Synopsis

A fiber bridged crack near a free surface in ceramic matrix composites is analysed. The crack is modeled as a continuous distribution of dislocations. The solution of a single dislocation in an elastically anisotropic half plane is derived using complex variable analysis. This solution, combined with fiber-bridging mechanics, is used to study the toughness increase in unidirectionalfiber reinforced ceramics. The crack can have arbitrary orientation with respect to the axis of the material symmetry. The bridging force is assumed to have a power law relationship with displacements of discontinuity on the crack planes. For a nonlinear relationship, the equation is linearized and solved numerically by an iteration scheme. The iteration scheme converges well for both short and long cracks. Numerical results for far field tension in fiber direction are presented. It is found that the free surface effect is reduced by fiber bridging of the crack.