Interaction between patch loading, bending moment, and shear stress in steel girders

Abstract

In bridge erection, a steel girder undergoing in-plane loading is commonly subjected to the interaction of several forces. Many previous studies have highlighted the effects of single in-plane loads on plate buckling but only a few works concentrated on the combined effects. For this reason, the stability of steel plates subjected to the combined action of patch loading, bending moment, and shear stress was studied through parametric analysis in this work. In particular, the effect of patch loading length combined with bending and shear stress was investigated. Other parameters like patch loading magnitude, panel aspect ratio, and plate slenderness have also been considered to characterize the plate stability. Through an intensive finite element method (FEM) analysis, new design equations have been defined to describe the influence of plate and load parameters on critical buckling loads of plates subjected to combined loads, with regard to plates subjected to patch loading. A comparison with the FEM results offers good accuracy, with a maximum deviation equal to 5%. To validate the analytical equations, a practical example is given.

目 的

通过深入的数值分析研究面内综合加载条件下钢板的临界屈曲荷载变化规律。

创新点

• 1. 提出一个确定钢梁在平面荷载作用下的临界屈曲系数的新公式;

• 2. 通过与有限元分析结果对比以修正参数并获得解析公式的高精度。

方 法

• 1. 采用有限元分析软件Strand 7 研究矩形钢板在节点荷载、 弯矩和剪应力综合作用下的弹性稳定性;

• 2. 针对节点荷载长度、 载荷大小、 板长宽比和长径比等参数分析对综合加载条件下的钢板稳定性的影响;

• 3. 借助一个实际的例子验证解析公式的有效性。

结 论

• 1. 通过与有限元结果的比较, 解析公式均表现出较高的精度, 误差均在有限范围内且不受板几何形状的影响;

• 2. 节点荷载、 弯矩和剪应力的综合作用通过减小板临界抗屈曲性导致钢板的屈曲失效;

• 3. -

综合加载会导致临界抗屈曲性减小一半。