Virtual Lab Fracture Test
- Fracture Test Quiz - Answers
- 1. Fracture mechanics
- 2. Critical stress intensity factor
- 3. Crack
- 4. Strain energy
- 5. Total energy
- 6. ac
- 7. ac
- 8. Crack tip
- Fracture Test Quiz and Answers
- 1. The term _______ refers to vital specialization within solid mechanics in which the presence of crack is assumed and we wish to find quantitative relations between the crack length, the material’s inherent resistance to crack length, and the stress at which the crack propagates at high speed to cause structural failure.
Answer. fracture mechanics
2. The _________ is a measure of material toughness.
Answer. critical stress intensity factor
3. When a _____ reaches a certain critical length, it can propagate catastrophically through the structure, even though the gross stress is much less than would normally cause yield or failure in a tensile specimen.
Answer. crack
4. When a crack has grown into a solid to a depth ‘a’, a region of material adjacent to the free surfaces is unloaded, and its ______ released.
Answer. strain energy
5. The ______ associated with the crack is then the sum of the (positive) energy absorbed to create the new surfaces, plus the (negative) strain energy liberated by allowing the regions near the crack flanks to become unloaded.
Answer. total energy
6. If ‘a’ is crack length and ‘ac’ is critical crack length, up to the point where ‘a’ = ____, the crack will grow only if the stress is increased.
Answer. ac
7. If ‘a’ is crack length and ‘ac’ is critical crack length, beyond the point where ‘a’ > ____, the crack growth is spontaneous and catastrophic.
Answer. ac
8. A "plastic zone" is present near the _____.
Answer. crack tip
