13th International Conference on Fracture June 16-21, 2013, Beijing, China 0 5e-13 1e-12 1.5e-12 2e-12 2.5e-12 3e-12 3.5e-12 0 0.002 0.004 0.006 0.008 0.01 0.012 Bending moment Bending angle Discrete Structure Bending Strength Hirarchy Structure Bending Strength Theoretical Bending Strength’ Figure 10. Strength of different models Figure 11. Deformed Microscopic Structures 0 5e- 13 1e- 12 1. 5e- 12 2e- 12 2. 5e- 12 3e- 12 3. 5e- 12 0 0. 002 0. 004 0. 006 0. 008 0. 01 Bendi ng Moment Bendi ng Angl e Bendi ng Moment of Hi er ar chi cal St r uct ur e （1） （2） （3） （4） （5） （6） （7） （8） Figure 12. Separations on cohesive zone during crack propagation of the cohesive zone. When first jump happens in Fig.12 at (1) and (2), the first unit hierarchical structure separates completely and crack propagates as in Fig. 13(a) and Fig. 13(b). The second jump at (3) and (4) corresponds to Fig. 13(c) and Fig. 13(d), half of the unit structure separates while the other half parts contains both bonding and separated elements. This half parts completely separates at (5) and (6) shows in Fig12 without jumps.After the first two unit structures separate completely, the third one begin to separates at (7) and at (8) half of the unit structure thoroughly separates. The hierarchical structure separates at a certain distributive way. Due to the special feature of hierarchical structure, the elements do not separate in regular order. Instead, after the initial separation, the element separates next shifts in one structure. After all the elements separate in one structure, the crack propagation happens. While for discrete structure, the elements separate in the regular order, after the first separation happens, the elements next separates sequentially. Discrete structure may be destroyed quickly after the first element separation, while hierarchical structure can suffer more due to its special separating feature. -8-
RkJQdWJsaXNoZXIy MjM0NDE=