Aspecimen of a 4340 steel alloy having a plane strain fracture toughness of 45 mpa√m (41 ksi√ is exposed to a stress of 1000 mpa (145,000 psi). will this specimen experience fracture if it is known that the largest surface crack is 0.75 mm (0.03 in.) long? why or why not? assume that the parameter y has a value of 1.0. (

Describe one experiment in which the glass transition temperature and melting temperature of a totally amorphous thermoplastic material can be determined. show the relevant experimental results in a diagram which should be properly annotated with the two temperatures clearly marked. what is likely to happen to the curve in the diagram if the amorphous polymer is replaced by a thermosetting type?