Effects of Fiber Directions on Strengths of Notched Specimens of C/C Composite

Tensile and fatigue failure behavior of C/C composites with fine woven fiber-cloth laminates was investigated in several configurations of specimens. A 3.2mm thick plate, which has the quality of machine-ability, was used for testing material. During the machining process of specimens, care was taken that the fiber directions of 0 degree /90 degree and -45 degree /45 degree orientation were set against the loading direction. Tensile and fatigue tests were performed under load control techniques. Notches were made on some specimens, and their fracture behavior was observed. Some different notch shapes were used to investigate the effect of fiber orientation on the fracture behavior of the material. The results showed that the critical fracture stresses on the specimen were affected by fiber orientation and notch shape. In addition, the shear stress conditions affected the fracture behavior.