A beam with a rectangular cross section has dimensions, as defined in Fig. 8.13, of b = 40and t = 10 mm. The beam is made of 7475-T7351 aluminum and is subjected to a bendingmoment of M = 900 N·m.
(a) If a through-thickness edge crack of length a = 5mm is present, what is the safetyfactor against brittle fracture?
(b) Repeat (a) for a crack length of 10 mm.
(c) What is the critical crack length for fracture?
(d) What crack length can be allowed if a safety factor of 3.0 against brittle fracture isrequired?