Notch geometry

Thus, it follows that at some reasonable distance from the notch, these effects on hydrogen diffusion (of notch geometry and non-uniform stresses) vanish and diffusion becomes stress-notch unaffected. According to this, a reduced... 

Figure 8.20 Various notch geometries can be used a) through-thickness crack and b) chevron notch. The shaded areas are the machined slots.

The value of Y is then necessary for different specimen geometries and different notch geometries. 

FIGURE 10. Schematic of Shear Notch Geometry with Fabric PUes... 

Fracture toughness. The orthotropic nature of wood also affects its fracture mechanics. Actually, timber fractures along the grains irrespective of the opening force and original notch geometry. 

Neuber s rule can be derived as an approximation. In the case of a parabolic notch and under the assumption of a certain simple stress-strain curve, a formula can be derived that simplifies to Neuber s rule in the case of a very sharp notch. For large notch radii, Neuber s rule is a conservative approximation i.e., it overestimates stresses and strains [106]. This conservative property of the rule is valid for most other notch geometries as well [59]. 

Click here to view Ti-10V-2Fe-3AI Effect of notch geometry on fatigue strength... 

To understand the effect of stress concentration of SiC/SiC composites, several coupons with different notch geometries were tested in tension. The geometries tested include double-radius (DR), double-slit (DS) and standard dogbone (DB), and are own schematically in Figure 1, where the dimensions shown in parenthesis indicate width from notch tip to notch tip (net width). Damage initiation and progression was monitored by modal acoustic emission and a finite element analysis was also performed to compare experimraital data with that of a semi-analytic model. 

The onset of damage, as observed by first acoustic emission event, showed a stress concentration effea for double-slit geometry only. Yet, both notch geometries exhibited comparable ultimate strength reduction, which was in very good agreement with results from the literature on similar composite systems and notch length. 

Figure 6. Notched impact strength of unfoamed and microcellular PC/ABS at RT and -30°C, notch geometry A and C... 

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