13th International Conference on Fracture June 16-21, 2013, Beijing, China dislocation on the right affects an attractive image force due to the traction-free boundary condition. According to the comparison between linear elasticity and hyper-elasticity models, both are almost same qualitatively. (i) linear elasticity model (ii) hyper-elasticity model (a) 1-slip plane model (i) linear elasticity model (ii) hyper-elasticity model (b) 3-slip plane model Figure 3. Distribution of stress σyy on deformed body For the 3-slip plane model in Fig.3(b), the manners of image forces that act dislocations are similar to that for the 1-slip plane model in Fig.3(a). However, according to the comparison between linear elasticity and hyper-elasticity models, there appears some difference. The shape of stress contour has symmetry with respect to the neutral axis for the linear elasticity model. It is naturally understood, because the principle of superposition can be assumed in the small deformation theory. On the other hand, the shape of stress contour has non-symmetry with respect to the neutral axis for the hyperelasticity model. This occurs due to the contribution of non-symmetric deformed shape of specimen. 3.2.2. Kink Deformation of Dislocations The kink deformation in model 1 (Fig. 4(a)) and model 2 (Fig. 4(b)) corresponds to a wedge-type and ridge-type kink deformations, respectively. The deformation in model 3 (Fig. 4(c)) consists of two wedge-type kink deformation patterns. When the two edge dislocation array near the center of specimen merges to a dislocation wall on a single plane, model 3 is reduced to model 2. These types of kink deformation are often observed in zinc and LPSO magnesium alloy. The discrete dislocation plasticity based on finite deformation theory will be applicable to the investigation of such kink -5-
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