桥式抓斗卸船机滑轮座底部裂纹的处理及分析

Treatment and analysis on crack at bottom of pulley block of bridge-type grab ship unloader

针对650 t/h桥式卸船机滑轮座根部出现的裂纹问题,分析了桥式卸船机滑轮座的工作状态,指出产生裂纹的原因是该处结构承受较大的交变应力和存在焊接缺陷所致。针对原设计的不足,提出通过改变滑轮座的结构形式来改变其应力分布的修复方案。基于Ansys软件的研究结果表明,该方案降低了滑轮座底部应力,使裂纹扩展现象停留在"裂纹萌生阶段",提高了设备的使用寿命。

Aiming at crack at bottom of pulley block of the 650t/h bridge-type grab ship unloader,the paper analyzes the working situation of pulley block and indicates the crack is caused by large alternating stress on the structure and welding defects.In response to the deficiency in original design,the paper proposes a repair plan to change its stress distribution through the structure of pulley block.The research result based on Ansys software shows that the plan reduces the stress at bottom of the pulley block to limit crack propagation in ＂crack initiation stage＂ and improves the service life of the equipment.