某中承式钢管混凝土桁式拱肋节点疲劳开裂分析

发布时间：2018-06-06 03:18

本文选题：钢管混凝土桁式拱桥 + 拱肋节点　；参考：《工程力学》2017年S1期

【摘要】：为了分析某中承式钢管混凝土桁式拱肋节点疲劳开裂的原因,运用有限元软件MIDAS/CIVIL建立全桥模型进行有限元分析。分别研究了不同车辆荷载和不同拱肋节点几何参数情况下拱肋节点应力幅的变化,进而分析了车辆超载和车辆中、偏载布置对拱肋节点应力幅的影响,并讨论了拱肋节点几何参数变化对拱肋节点应力幅的影响。研究表明,当车辆荷载超载30%、50%、100%和150%时拱肋节点应力幅基本呈线性增大,应力幅最大值达155 MPa。BS5400疲劳车辆荷载作用下拱肋节点应力幅最大,中国550 k N车辆荷载偏载作用下拱肋节点应力幅为中载1.2倍。超载和偏载分别是造成该钢管混凝土桁式拱桥拱肋节点出现疲劳开裂和疲劳裂缝分布不对称的主要原因。节点应力幅随弦杆和腹杆间壁厚比的增大而减小,而随弦杆和腹杆间管径比、弦杆径厚比和腹杆径厚比的增大表现为先增大后减小的趋势。
[Abstract]:In order to analyze the causes of fatigue cracking of a concrete filled steel tubular truss arch rib joint, the finite element software MIDAS/CIVIL was used to establish the full-bridge model for finite element analysis. The variation of stress amplitude of arch rib joint under different vehicle loads and different geometric parameters of arch rib joint is studied, and the influence of deflection load arrangement on stress amplitude of arch rib joint is analyzed. The influence of geometric parameters on the stress amplitude of arch rib joint is discussed. The results show that the stress amplitude of the arch rib joint increases linearly when the vehicle overload is 30% and 150%, and the maximum stress amplitude of the arch rib joint reaches the maximum value under the action of 155 MPa.BS5400 fatigue vehicle load. The stress amplitude of arch ribbed joint is 1.2 times that of medium load under the load bias of 550 KN vehicle in China. The main causes of fatigue cracking and asymmetric distribution of fatigue cracks in arch rib joints of CFST truss arch bridge are overload and eccentric load respectively. The stress amplitude of the joint decreases with the increase of the wall thickness ratio between the chord and the web rod, but with the increase of the diameter ratio between the chord and the web rod, the diameter to thickness ratio and the diameter-thickness ratio of the chord and the web rod increase first and then decrease.
【作者单位】：福州大学土木工程学院;长崎大学大学院工学研究科;
【基金】：国家自然科学基金项目(51408132)
【分类号】：U441.4

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