Fatigue Life Design of Mechanical Structure答案2023

第二章测试

1. Which is not the characteristic of slip （ ）
A:The same characteristics under monotonic loading and cyclic loading B:Occurring within individual grains by dislocation movement C:The relationship between dislocations and plastic deformation D:A shear deformation of the metal
答案:A
2. The characteristics of beach mark are as follows （ ）
A:Two adjacent crack surfaces with open, close, and rub B:Pattern of crack growth C:Crack’s starting, stopping and growing at different rates D:Wavy bands 3. Modes of fatigue crack growth with fracture are as follows （ ）
A:Trans-crystalline fracture B:Dislocation movement C:Inter-crystalline fracture D:Slip deformation 4. Crack nucleate at surface and grow across several grains (stage I, microcrack), and then to grow in a zigzag manner (stage II, macrocrack). （ ）
A:错 B:对 5. The mechanical property of each grain is the same. （ ）
A:错 B:对