基于疲劳强度设计的通用桥式起重机箱梁结构研究

The structure research of the general bridge's box bean based on fatigue strenth design

根据GB/T 3811-2008《起重机设计规范》结构件疲劳强度校核方法,结合目前普遍使用的QD通用桥式起重机的设计图纸和制造工艺,运用疲劳许用应力法对QD通用桥式起重机主梁跨中截面,进行疲劳强度校核,发现校核结果不能满足疲劳强度设计要求。通过改善生产制造工艺来提高焊接箱梁残余应力分布均匀性,减小理论应力集中系数,提高结构疲劳强度许用应力值。同时,通过改进结构尺寸减小主梁弯曲应力来满足疲劳强度校核值。最后比较了两种方法的经济性与合理性,提出改善生产制造工艺比较适用于通用桥式起重机主梁的疲劳强度设计。

Based on the structural component fatigue strength checking method of GB/T3811-2008 Design rules for cranes, combined with the design drawings and manufacturing process used widely for the QD general bridge cranes. The fatigue strength allowable stress method was applied for the checking of a bridge crane＇s beam midspan. It was tbund that the results can＇t meet the demand of fatigue strength design. Improving manufacturing process was used to increase the uniformity of the residual stress in the welding box beam. The theory stress concentration factor was reduced and the allowable stress of fati same time, improving the structure＇s dimension was used to reduced the ben gue ding strength was increased. At the stress in the beam, which can also meet the checking value of the fatigue strength. Finally, the economy and rationality was compared between the above two improving methods, and the improving manufacturing process was suggested to be used for the fatigue strength design for the beam in the general bridge crane