承受重复荷载的结构,有可能出现一种完全不同于丧失结构静力强度的破坏形式。这时结构的最大应力远远小于钢材静力强度(甚至小于钢材屈服点),但在荷载反复作用下,结构某些部位产生了微细裂纹,并随着反复次数的增加逐渐扩展为贯通的裂缝,以至撕裂构件,这种现象称之为疲劳破坏。 With structures subjected to repeated loads, it is possible to have a form of damage that is completely different from the loss of structural static strength. At this time, the maximum stress of the structure is far less than the static strength of the steel (even smaller than the yield point of the steel). However, under the repeated load, some cracks occur in some parts of the structure, and they gradually expand into cracks that pass through as the number of iterations increases. As far as tearing members, this phenomenon is called fatigue damage.