A model for the craze-flow stress of particle-toughened polystyrene

7 A model for the craze-flow stress of particle-toughened polystyrene 

To determine the mean distance /c between active crazes, consider a statistically equivalent plane-strain model of randomly positioned parallel cylindrical particles perpendicular to the tension axis. Then, as Fig. 13.9 shows, the mean vertical distance L between such particles is 

28) cq is made up of a number of factors defined in eq. (11.51) with numerical values listed in Table 11.2 both for PS and for PMMA, Tq = AGl/k, where AGq is given by eq. (11.52) with values ofln and oo also given in Table 11.2, 

Alternatively, can be given in more detail for operational purposes as 

In any blend having a normalized particle-size distribution g(D) of which a significant fraction falls below Dc only the fraction falling above Dc is effective and /must be modified by a factor l(Dc) defined as 

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