大跨度预应力管桁架结构煤棚支座节点分析

Analysis of coal shed support joint for large-span prestressed pipe truss structure

预应力拱形管桁架结构有跨越能力强、结构力学特性优越、储煤容量大的优点,已逐渐应用于大跨度煤棚。大跨度预应力管桁架结构煤棚支座处受力较大,支座节点大多采用半球节点。为了研究大直径支座焊接半球与支管连接的节点及其补强方式,利用有限元仿真软件MIDAS FEA对其进行线性及非线性分析,线性分析时局部很小区域应力集中明显而其他区域应力较小,计算结果失真,需做非线性分析。采用半球内加十字肋并在直径较小支管外侧设加劲肋可提高节点承载力,因此对不同厚度加劲肋节点做非线性分析,结果表明:当加劲肋厚度等于被加强支管的壁厚时,节点承载力有一定安全储备且较经济合理。

The prestressed arched tube truss structure has the advantages of strong spanning ability,superior structural mechanical properties and large coal storage capacity,and has been gradually applied to large-span coal sheds.The coal shed support of large-span prestressed pipe truss structure bears large forces,and most of the support joints are hemispherical.In order to study the joints connected with large diameter bearing welded hemispheres and branch pipes and their reinforcement methods,the finite element simulation software MIDAS FEA is used for linear and nonlinear analysis.In the linear analysis,the stress is concentrated in a small area and the stress in other areas is small,the calculation result is distorted,and a nonlinear analysis is required.The bearing capacity of the joint can be improved by adding cross ribs in the hemisphere and stiffening ribs outside the branch pipe with small diameter,so the nonlinear analysis of stiffener joints with different thickness is conducted.And the result show that,when the stiffener is as thick as the wall of the reinforced branch pipe,the bearing capacity of the joint has a certain safety reserve and is more economical and reasonable.