Crack bowing

However, the presence of crack-front bowing indicates that some imenacial adhesion in these composites does exist. The extent of bowing will be dependent on the strength of adhesion, with more extensive crack bowing occurring with strong adhesion. 

This mechanism has been analyzed theoretically and various calculations have shown that crack bowing should lead to an increase in fracture toughness. For... 

Figure 8.51 Interaction of a crack front with an inclusion in glass showing crack bowing. The marks on the fracture surface were produced by ultrasonic fractography (frequency 1 MHz) and reflect successive crack front positions at 1 (is intervals.

Why does crack bowing increase fracture toughness ... 

Crack bowing Bowing in the crack plane between second-phase crack-pinning points... 

A model which mathematically describes the crack bowing effect as well as the abihty of an impenetrable particle to act as a spring (16) is... 

Fig. 5.58 Comparison of toughening in Zn0/Zr02 with that for glass/alumina. Also shown are toughness levels predicted for crack-deflection and crack-bowing mechanisms [28]. With kind permission of John Wiley and Sons...

Because of the resistance of the particles, the crack bows between them, causing the stress intensity, K, at the particle to increase, while, in the bowed segment of the crack, a softening effect occurs, i.e., K decreases along this segment. Bowing... 

FIGURE 13.1.1 A tensile crack bowing between dispersed particles (after Ref. [2]). 

Many studies on the fracture toughness of particulate composites consider the crack-bowing mechanism as the main toughening mechanism. Lange (1970) first... 

Figure 2.6 illustrates crack bowing, crack deflection, debonding, and step structure mechanisms, which may be operative to a system. Figure 2.6a shows the occurrence of the crack-bowing mechanism when the propagating aack interacts with fillers... 

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