经对断口的宏观分析、起重臂的力学计算，以及对起重臂的工作受力状态和安全性的讨论，最后判定断裂是由于主臂构造缺陷和疲劳所致。

Macro check on the breaking section and mechanics calculation of the jib are performed. The force status and safety of the jib are also discussed.

youdao

经对断口的宏观分析、起重臂的力学计算，以及对起重臂的工作受力状态和安全性的讨论，最后判定断裂是由于主臂构造缺陷和疲劳所致。

Macro check on the breaking section and mechanics calculation of the jib are performed. The force status and safety of the jib are also discussed.

youdao