铸造起重机结构疲劳再制造关键技术

Research on structural fatigue and key manufacturing technologies of casting crane

铸造起重机常在高工作级别中工作,由于焊接工艺的缺陷,在使用过程中经常产生焊缝开裂等情况,需要进行焊接修复,修复的质量决定了起重机安全运行的时长。针对以上问题,文中提出了一种基于强度的起重机焊缝开裂修复的设计方法,通过对铸造起重机进行实地测量和分析确定易开裂的焊缝位置,并建立对应的有限元整机模型;对产生开裂位置处局部结构进行改进,确定局部应力变化范围,划分子模型;同时以子模型作为研究对象,导入Ansys软件中进行局部应力分析,以加固结构的最大等效应力作为优化目标,对修复结构的特征几何尺寸进行多参数的耦合仿真试验分析,采用交叉试验方法最终得到强度最高的焊缝裂纹修复结构。

Casting cranes are often used in high-level applications.Due to the defects of welding technology,cracks in welding seams often occur in cranes during use,which requires welding repair.The repair quality determines the safe operation time of cranes.Considering the above problems,in this paper,a strength-based repair method of crane weld crack is proposed.The location of the easily cracked weld is determined by field measurement and analysis of casting cranes,and a finite element model is established.The local structure at the crack-prone position is improved,the variation range of local stress is determined,and submodels are established;the local stress analysis is carried out by importing Ansys software,and the maximum equivalent stress of the reinforced structure is taken as the optimization objective.Multi-parameter coupling simulation test is carried out on the characteristic geometry size of the repaired structure,and the repaired structure with the highest strength of weld crack is obtained by cross test.