Stress intensity factors of partially compressed centrally cracked disk with frictional crack surfaces

This work analytically calculates mixed-mode I/II stress intensity factors for an inclined central frictional crack in a Brazilian disc partially compressed with a uniform pressure. Wide-range controlling parameters are invoked. The analyzed parameters include the pressure angle, relative crack length, crack inclination, and friction coefficient between the two crack surfaces. For partially compressed discs, there exists a critical pressure angle at which a crack with any angle will experience pure II loading. This critical pressure angle is not affected by friction and decreases as the crack length increases. A crack of any angle becomes inactive once the pressure angle exceeds another critical value of pressure angle. This value decreases as the friction coefficient or/and crack length increases. The handling of frictional surfaces of short cracks is simplified. The analysis defines the conditions to have (1) the crack opened and (2) the two crack surfaces sticking. A close agreement is achieved with relevant findings in previous relevant investigations. The present results do not exist in relevant literature and are valuable in solving fracture mechanics problems of significance in relation to crack path in cracked brittle materials.