An analysis of Weibull distribution for residual and fracture strength after proof testing of ceramics

By assuming that the crack velosity (a) over dot can be expressed as a power function of the stress intensity K-I, (a) over dot proportional to K-n(I), the degradation of strength during proof test of ceramic materials was analyzed, and Weibull distributions both for residual strength Sr and fracture strength sigma(F) after proof testing were analytically formulated. The analytical results show that Weibull curve for the S-tau has a slope of about -2 at low failure probability levels (n; the proof test environments), and also show that the corresponding Weibull curve for the sigma(F) has a slope of about (n-2)(N+1)/(N-2) (N ; the fracture test environments).