Y.-C. Chiang/ Engineering Fracture Mechanics 6.5(2000)15-28 10 5/=m=0 10 t MPa) Fig. 5. Debonding length vs frictional shear stress at different sa/5m for SiC/borosilicate composite, the fiber diameter d= 2a. stress, as shown in Fig. 6. However, the higher Sd/sm and ts also result in shorter debonding length. The composite with shorter debonding length will have smaller fiber pull-out length which results ie interfacial debonding process is the prerequisite for the process of fiber pull-out. It implies that the smaller work of fracture. This inverse relation between matrix cracking stress and work of fracture 500 IOMPa 0.0 0.3 5/m Fig. 6. Matrix cracking stress vs. a/5m at different frictional shear stress for SiC/borosilicate composite.stress, as shown in Fig. 6. However, the higher zd=zm and ts also result in shorter debonding length. The interfacial debonding process is the prerequisite for the process of ®ber pull-out. It implies that the composite with shorter debonding length will have smaller ®ber pull-out length which results in a smaller work of fracture. This inverse relation between matrix cracking stress and work of fracture is Fig. 5. Debonding length vs. frictional shear stress at di€erent zd=zm for SiC/borosilicate composite, the ®ber diameter d ˆ 2a: Fig. 6. Matrix cracking stress vs. zd=zm at di€erent frictional shear stress for SiC/borosilicate composite. 24 Y.-C. Chiang / Engineering Fracture Mechanics 65 (2000) 15±28