重型钢结构厂房吊车梁更换改造的设计分析

DESIGN AND ANALYSIS OF CRANE GIRDER REPLACEMENT FOR HEAVY STEEL STRUCTURE PLANT

直角式截面突变吊车梁在实际使用中出现了普遍性的疲劳裂缝,着重分析了该吊车梁开裂的原因,并对变截面直角式突变吊车梁与变截面圆弧式突变吊车梁进行了比选研究及有限元模型分析,阐述了两类变截面吊车梁的局部应力状态。分析结果表明,三腹板变截面直角式吊车梁最大应力幅较高,易引起明显的应力集中,而三腹板变截面圆弧式吊车梁最大应力幅最低,安全可靠性较高。最终提出了三腹板变截面圆弧式吊车梁的改造方案及设计控制的主要指标,满足了厂房各项设计要求。

Prevailing fatigue cracking has been witnessed in practical abrupt variable cross section crane girders with the right-angle support. The paper analyzed the reasons of the cracking of this crane girder. The comparison and finite element analyses of the variable cross-section crane girder with the right-angle support and the variable section crane girder with the arc-shape support were carried out. The local stress states of two types of variable cross-section crane girders were described. The analysis results showed that the maximum stress of the three-web cross section crane girder was higher and the stress concentration was obvious,while the maximum stress of the three-web variable cross-section circular arc crane girder was the lowest. So it was highly safe and reliable. And the transformation scheme and the design control index of the three-web variable cross-section circular arc crane girder were clarified,which could meet the design requirements of the workshop and realize the design goal.