拧入缺陷对螺栓球节点受力性能影响

发布时间：2018-09-15 19:30

【摘要】：螺栓球节点在空间网格结构中应用广泛,然而由于其组成构件较多,在安装过程中容易出现高强螺栓拧入长度不足的初始缺陷.为研究该缺陷对螺栓球节点受力性能的影响,采用ANSYS软件建立了带有螺纹的螺栓球节点精细化模型,通过改变螺纹的啮合数来模拟高强螺栓的拧入长度,并利用已有试验数据对模拟方法的准确性进行了验证.在此基础上,对M20、M24、M27三种常用节点在不同拧入长度下的抗弯性能进行分析,结果表明螺栓球节点随着拧入长度的变化主要存在三种工作及破坏模式,高强螺栓拧入长度不足可严重降低节点刚度及其极限承载力.最后对上述三种节点在不同拧入长度下的抗拉性能进行模拟分析,得到了不同拧入长度下螺栓球节点抗拉承载力的退化规律及可能的破坏模式,给出了抗拉承载力降低比例与螺栓拧入长度的关系曲线,研究成果可为螺栓球节点的施工控制及相似结构的安全性能评估提供技术参考.
[Abstract]:The bolted ball joints are widely used in spatial grid structures, however, due to the large number of components, the initial defects of high strength bolts with insufficient length are easy to occur in the installation process. In order to study the effect of the defect on the mechanical performance of the bolt joint, a precise model of the ball joint with thread was established by using ANSYS software. The screw length of the high strength bolt was simulated by changing the mesh number of the thread. The accuracy of the simulation method is verified by the existing experimental data. On this basis, the bending resistance of M20M24M27 joints under different screw length is analyzed. The results show that there are three main working and failure modes for bolted joints with the change of screw length. The stiffness and ultimate bearing capacity of joints can be seriously reduced by insufficient screw length of high strength bolts. Finally, the tensile properties of the three joints are simulated and analyzed under different twisting lengths, and the degradation law and possible failure mode of the tensile bearing capacity of the bolted joints with different screw lengths are obtained. The relationship curve between the proportion of tensile bearing capacity and bolt length is given. The research results can provide a technical reference for the construction control of bolt joints and the evaluation of safety performance of similar structures.
【作者单位】：哈尔滨工业大学(威海)土木工程系;哈尔滨工业大学土木工程学院;
【基金】：国家自然科学基金青年基金(51308154) 威海市科技发展计划(2016DXGJMS03) 国家重点研发计划(2016YFC0802003)
【分类号】：TU31

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