基于微观断裂机制的XK型相贯节点极限承载力分析

发布时间：2018-06-19 05:51

本文选题：相贯节点 + 极限承载力　；参考：《土木工程学报》2017年07期

【摘要】：采用基于微观断裂机制的空穴扩张模型(VGM)和应力修正应变模型(SMCS)对XK型相贯节点进行断裂预测,分析了有限元模型中考虑焊缝构型与否对断裂预测结果的影响。通过与试验结果的对比,证明了合理考虑焊缝构型在相贯节点断裂预测中的重要性,验证了VGM模型用于预测相贯节点在单调荷载作用下延性断裂的适用性。分析了XK型相贯节点在腹杆轴力作用下的破坏模式和极限承载力。结果表明,XK型相贯节点可能在受拉腹杆与弦杆之间的焊缝处发生断裂,这种破坏模式属于强度破坏,节点极限承载力应取该断裂荷载;XK型相贯节点也可能在受压腹杆与弦杆相交处因过大的塑性变形而破坏,此时,节点极限承载力应取荷载-弦杆变形曲线的峰值荷载。XK型相贯节点的破坏模式与节点几何构造和腹杆受力状态有关。
[Abstract]:The hole expansion model (VGM) based on micro fracture mechanism and the stress modified strain model (SMCSS) are used to predict the fracture of XK type intersecting joints. The influence of weld configuration on fracture prediction results in finite element model is analyzed. By comparing with the experimental results, the importance of considering the weld configuration in the fracture prediction of intersecting joints is proved, and the applicability of VGM model in predicting ductile fracture of intersecting joints under monotone load is verified. The failure mode and ultimate bearing capacity of XK type intersecting joints under the action of web rod axial force are analyzed. The results show that the XK type intersecting joint may break at the weld between the pull web rod and the chord, and this failure mode belongs to the strength failure. The ultimate bearing capacity of the joint should be taken as the fracture load and the XK type intersected joint may also be destroyed by excessive plastic deformation at the intersection of the compression web bar and the chord. The ultimate bearing capacity of the joints should be taken as the peak load of the load-chord deformation curve. The failure mode of the XK type intersected joints is related to the geometric structure of the joints and the stress state of the web bars.
【作者单位】：天津大学建筑工程学院;天津大学滨海土木工程结构与安全教育部重点实验室;中国建筑西南设计研究院有限公司;中国电力工程顾问集团中南电力设计院有限公司;
【分类号】：TU392.3

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