某小区电梯在空载运行时钢丝绳发生断裂，导致电梯突然停止运行。通过现场勘查、宏观观察、化学成分分析、破断拉伸试验、扫描电镜分析的方法，对钢丝绳的断裂原因进行了分析。结果表明：钢丝绳起裂源位于钢丝心部，断裂性质为一次性韧性断裂，断裂是由单根钢丝绳过载造成的。

The steel wire ropes of the elevator in a housing estate fractured during no-load operation, which led to a sudden stop running of the elevator. Through the site investigation, macroscopic observation, chemical composition analysis, breaking tensile testing and scanning electron microscope analysis, the fracture reasons of steel wire ropes were analyzed. The results show that:the crack source of the steel wire rope was located in the core of the steel wire rope; the fracture mechanism was one-time ductile fracture; the fracture was caused by the overload of single steel wire rope.