試題詳解

19. The process of fatigue failure is characterized by the steps including
(A) initial crack forms at the forced point once the load is applied,
(B) the advancing creak from the initial stage has reached a critical size during the stress cycle,
(C) the crack propagation is stopped by the plastic formation due to the interaction of dislocations,
(D) increasing temperature owning to stress cycle melts the bend location, and
(E) all of the above.