Periodic inspection and maintenance of cracks have great influence on the reliability and safety of metal structures of bridge cranes. However, the influence of maintenance factors on the fatigue reliability of in-service bridge cranes is rarely considered at present. Taking a metal structure of a certain type bridge crane as an example, this paper establishes the limit state equation according to the residual strength of the structure. Considering the reduction of section modulus by fatigue cracks, the influence of periodic inspection and maintenance is quantitatively analyzed. The fatigue reliability of metal structure of bridge crane is analyzed and calculated by using MATLAB program. The results show that the fatigue damage will lead to the continuous decrease of reliability, and the fatigue reliability of metal structure can be restored to a certain extent by considering maintenance, which delays the decrease of reliability.

中文翻译：

---

考虑维修的桥式起重机金属结构疲劳可靠性分析

裂缝的定期检查和维修对桥式起重机金属结构的可靠性和安全性影响很大。但目前很少考虑维修因素对在役桥式起重机疲劳可靠性的影响。以某型桥式起重机的金属结构为例，根据结构的剩余强度建立极限状态方程。考虑到疲劳裂纹对截面模量的降低，定量分析了定期检查和维修的影响。利用MATLAB程序对桥式起重机金属结构的疲劳可靠性进行了分析计算。结果表明，疲劳损伤会导致可靠性不断下降，