单层网壳新型半刚性节点性能研究

发布时间：2018-04-23 21:26

本文选题：单层网壳 + 切削空心圆柱节点　；参考：《北京交通大学》2017年硕士论文

【摘要】：单层网壳结构以其受力合理,用料经济,造型美观等优点被日益广泛应用。相关规范基于安全考虑,规定分析单层网壳时应假定节点为刚接。但实际上,网壳的节点是半刚性的。如果将节点视为完全刚接或完全铰接,会过高或过低地估计结构的实际承载能力,这对于建筑的经济性、安全性都是不利的。半刚性节点与刚接节点相比具有一定的转动能力,与铰接节点相比又具有一定的抗弯刚度,且其具有装配方便,外形美观的优点。因此,对半刚性节点性能开展深入的研究并将其应用到单层网壳结构中具有重要的理论意义与实用价值。本文构思设计了一种新型切削空心圆柱节点。该节点由螺栓装配而成,是一种半刚性节点。为分析该节点在单层网壳中沿径向和沿环向的节点性能,分别开展了节点在径向加载和环向加载两种情况下的试验研究。得到了节点的荷载-位移曲线、应力变化曲线、弯矩-转角曲线,分析了节点的受力机理和失效模式,获得了节点径向与环向的初始刚度值和极限抗弯承载力值,对比了节点径向和节点环向性能的异同。这为开展切削空心圆柱节点和其他半刚性节点性能的进一步研究提供了分析思路和试验基础。在此基础上,利用ABAQUS有限元软件进行了切削空心圆柱半刚性节点径向和环向的节点性能有限元模拟研究。数值模型的节点受力机理与实际试验吻合良好。为了进一步研究节点的性能,模型改善了试验时节点螺栓预紧力不足的局限,使得数值模拟结果体现出的节点承载性能有一定的提高,杆件上的强度也得到了更为充分的利用。接着分析了各种参数对节点性能的影响,发现在一定范围内,螺栓直径、螺栓预紧力对节点径向与环向性能均有一定影响且规律一致。此外,承载时预留安装孔处有较为明显的应力集中,使得节点环向承载能力有较为明显的下降。本文通过试验和数值模拟研究了新型切削空心圆柱半刚性节点的性能。
[Abstract]:Single-layer reticulated shell structure has been widely used for its advantages of reasonable force, economical material use and beautiful shape. The relevant specifications are based on safety considerations and stipulate that the nodes should be rigidly connected when analyzing single-layer latticed shells. In fact, the nodes of the reticulated shell are semi-rigid. If the joints are considered to be completely rigid or fully hinged, the actual bearing capacity of the structure will be estimated too high or too low, which is unfavorable to the economy and safety of the building. Compared with the rigid joints, the semi-rigid joints have a certain rotation ability, and have a certain bending stiffness compared with the hinged joints, and it has the advantages of convenient assembly and beautiful appearance. Therefore, it is of great theoretical significance and practical value to study the performance of semi-rigid joints and apply them to single-layer latticed shell structures. In this paper, a new type of cutting hollow cylindrical node is designed. The joint is assembled by bolts and is a semi-rigid joint. In order to analyze the performance of the node in the single-layer latticed shell along radial and circumferential directions, the experimental study was carried out under radial loading and toroidal loading respectively. The load-displacement curve, stress change curve, moment and angle curve of the joint are obtained. The stress mechanism and failure mode of the joint are analyzed, and the initial stiffness and ultimate flexural bearing capacity of the joint are obtained. The radial and annular performance of the joints are compared. This provides an analytical and experimental basis for further research on the properties of cutting hollow cylindrical joints and other semi-rigid joints. On this basis, the finite element simulation of radial and toroidal joint performance of hollow cylindrical semi-rigid joints is carried out by using ABAQUS finite element software. The stress mechanism of the numerical model is in good agreement with the actual test. In order to further study the performance of the joint, the model improves the limitation of the insufficient pre-tightening force of the joint bolt during the test, which makes the numerical simulation results reflect the joint bearing performance to a certain extent, and the strength of the bar is also more fully utilized. Then the influence of various parameters on the joint performance is analyzed. It is found that in a certain range the bolt diameter and bolt pretension force have certain influence on the radial and circumferential performance of the joint and the law is consistent. In addition, there is obvious stress concentration at the place where the installation hole is reserved for loading, which makes the load bearing capacity of the node in the circumferential direction decrease obviously. In this paper, the performance of a new type of cutting hollow cylindrical semi-rigid joints is studied by experiment and numerical simulation.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU399

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