起重机械承力构件应力集中分析

以双梁桥式起重机为例,通过对承力构件的应力分析计算,探讨起重机械中存在的应力集中现象,以及由此引起的疲劳裂纹。分析计算表明,正常情况下,主梁的弯曲正应力及弯曲剪应力均满足要求,但由于主梁有仓门处的形状突变及表面粗糙,应力集中度大,不满足剪切疲劳强度要求。因此,承力构件出现的裂纹是应力集中引起的疲劳裂纹。建议对在用的起重机械承力构件进行应力集中分析,及时消除安全隐患。

Analysis of Stress Concentration in the Force-bearing Component of Hoisting Machinery

This article took a double beam bridge crane as an example,through the stress analysis and calculation of the force-bearing component,discussed the stress concentration of hoisting machinery and the fatigue crack caused by it.The analysis and calculation showed that the bending normal stress and bending shear stress all met the requirements in normally,but the large stress concentration degree caused by the shape mutation and surface roughness made the share fatigue strength do not met the requirements.Therefore,the crack in the force-bearing component was the fatigue crack caused by stress concentration.The suggestion is carrying out stress concentration analysis for the force-bearing component of hoisting machinery in use to eliminate the hidden danger in time.