Weibull flaw sizes, relative frequency

Fig. 1 a) Strength data of a silicon nitride ceramic tested in four point bending (4PB) in a Weibull plot and b) the relative frequency distribution of flaw sizes. The data points were determined by fracture experiments. 

Figure 12.12 Relative frequency of flaw sizes versus their size. The distribution is plotted in a log-log scale. Shown are data of the same experiments as in Figure 12.8. The data are nicely arranged around a straight line, which indicates the Weibull behavior of the materiai (for details of the data evaluation, see Ref. [62]). The dashed areas correspond to the parameter...

Figure 12.13 Bimodal flaw size distribution a narrow peaked flaw population is superposed to a wide population, (a) Relative frequency of flaw sizes (bottom) and density of critical flaw sizes (top) versus the flaw size (b) Weibull plot showing the probability function (through line)...

In cases where the relative frequency of flaw sizes has a shape different to that of a Weibull material, the Weibull modulus becomes stress-dependent. The same happens for bimodal and multimodal flaw distributions [70, 71]. 

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