工业厂房吊车梁肩梁的疲劳失效机理分析及结构优化研究

Fatigue Failure Mechanism Analysis and Structure Design Optimization of Crane Shoulder Beam in Industrial Plant

钢结构工业厂房柱肩梁时常产生疲劳开裂现象,对厂房安全产生威胁。为了改善这一现状,本文以某实际工程中设计并应用的单壁式钢肩梁为研究对象,利用ANSYS模拟其承受上柱荷载及吊车梁传递荷载时的反应,分析肩梁的应力分布,找出危险点。通过雨流计数法处理危险点的应力数据得到肩梁的应力谱,并通过常用的3种疲劳分析方法预测肩梁的疲劳寿命。讨论了增加上盖板厚度及设置斜腹板带来的影响,并进一步尝试采用组合结构来简化原肩梁结构形式。结果表明原结构肩梁的预测疲劳寿命水平较低,合理改变相关参数可以有效降低危险点的应力值,而组合结构形式可以避免肩梁拉应力的出现,此两种结构优化方法均可以提高肩梁的疲劳寿命水平。

Fatigue cracks often occur in steel column shoulder beams of industrial buildings,threatening the safety of industrial structures.In this paper,the single-wall steel shoulder beam is selected as the object to study how to improve this situation.The software ANSYS is used to simulate and analyze the stress distribution of the steel shoulder beam under the loads transferred from the upper column and the crane beam,and to locate the critical point.The stress spectrum of the shoulder beam is obtained by using rain-flow counting method,and its fatigue life is predicted by three different fatigue analysis methods.The influence of parameters such as the thickness of the upper cover plate and the angle of the inclined webs is discussed.The expected fatigue life level of the original steel shoulder beam is low.The study shows that the stress at the critical point can be reduced by appropriately changing some parameters,and the use of composite structure to simplify the original shoulderbeam structure can avoid the appearance of shoulder-beam tensile stress.Both of those two structural design optimization forms can improve the fatigue life level of the shoulder beam.