Chapter 2, Problem 6P

Several of the property tests described in this chapter produce results that are quite sensitive to the presence or absence of notches or other flaws. The fracture mechanics approach to materials testing incorporates flaws into the tests and evaluates their performance. The review article mentioned in question 4 earlier cites the key role of a flaw or defect in nearly all of the headline�news fractures.

1. What are some of the various “flaws or defects” that might be present in a product? Consider flaws that might be present in the starting material, flaws that might be introduced during manufacture, and flaws that might occur due to shipping, handling, use, maintenance, or repair.
2. What particular properties might be most sensitive to flaws or defects?
3. Discuss the relationship of flaws to the various types of loading (tension vs. compression, torsion, shear).
4. Fracture mechanics considers both surface and interior flaws and assigns terms such as “crack initiator,” “crack propagator,” and “crack arrestor.” Briefly discuss why location and orientation may be as important as the physical size of a flaw