盲眼螺栓Hollo-bolt抗拉性能研究

发布时间：2018-06-15 03:42

本文选题：盲眼螺栓Hollo-bolt + 抗拉性能　；参考：《烟台大学》2017年硕士论文

【摘要】：盲眼螺栓HB用于梁柱半刚性连接节点的受拉区域时,节点会因螺栓HB的套管被剪断或者整个螺栓体从螺栓孔被拔出而提前失效,进而导致结构的可靠度指标偏低。故尚需解决盲眼螺栓Hollo-bolt的抗拉承载力较差的问题。然而,目前对盲眼螺栓HB抗拉性能的研究存在以下两点不足:(1)通过混凝土的粘结效应来提高盲眼螺栓HB抗拉承载力的研究仅局限于结构层面,然而,通过考虑混凝土的粘结效应以提高单个盲眼螺栓HB的抗拉性能的研究还缺乏相关的研究方法和试验数据;混凝土的粘结效应对通过焊接锚固钢筋改良的盲眼螺栓HB的作用机理也尚不明确;(2)目前,国内外对盲眼螺栓HB T-型连接抗拉性能的研究主要集中于对传统T型连接的研究,而对通过两角钢背对背形成的T型连接的抗拉性能研究鲜有报道。混凝土的粘结效应和角度厚度等变量对此类T型连接中盲眼螺栓HB的抗拉性能影响还缺乏必要的试验和理论研究。因此,本文基于以上两点研究不足,分别从构件层次和结构层次开展盲眼螺栓HB抗拉性能研究具有重大的工程意义。本文主要工作如下:第一:采用新型抗拔试验装置,对各种工况下的单个盲眼螺栓HB进行了抗拉试验。试验变量包括螺栓类型、混凝土强度等级和是否考虑混凝土粘结效应等。试验获得了试件的破坏模式和荷载-位移关系曲线,主要从刚度、强度、延性和断裂能四个方面考察各种工况下盲眼螺栓HB的抗拉性能。结果表明:考虑混凝土粘结效应的改良后盲眼螺栓HB的抗拉性能可以与同等级普通高强度螺栓相媲美,甚者,更为优越;第二:运用有限元软件ABAQUS建立15个螺栓轴向拉伸有限元模型。通过文献试验结果和本文试验结果与有限元模拟结果进行比较,以验证有限元模型的有效性。通过对比发现:有限元结果和试验结果以及文献试验结果吻合较好,从而为后文盲眼螺栓HB三阶段刚度模型提出做准备;第三:基于诺丁汉大学的研究,对Type A、Type B和Type C三类盲眼螺栓HB进行机理分析;基于弹簧串并联刚度关系,运用组件法量化得出初始阶段套管、中心螺杆、锚固钢筋和混凝土对分担外拉力的贡献作用;基于现有对螺栓刚度的研究,并在大量有限元分析拟合的基础上,提出盲眼螺栓HB的三线段刚度模型并验证其有效性。结果表明:盲眼螺栓HB三阶段刚度模型可用于工程结构的刚度预测;第四:对7个通过角钢形成的螺栓T-型连接件进行轴向拉伸试验。试验得到了试件的破坏模式,荷载—位移关系曲线,应变-时程曲线等数据,并初步探究了螺栓类别、钢管柱壁的厚度、角钢的厚度等对节点的刚度、承载力、延性以及耗能的作用机理和影响规律。
[Abstract]:When the blind bolt HB is used in the tension area of Liang Zhu semi-rigid connection, the joint will be cut off by the casing of bolt HB or the whole bolt body will be pulled out from the bolt hole, which will lead to the low reliability index of the structure. Therefore, it is necessary to solve the problem of poor tensile capacity of blind bolt Hollo-bolt. However, the current research on HB tensile capacity of blind bolt is limited to the structural level through the bond effect of concrete. By considering the bond effect of concrete to improve the tensile performance of single blind bolt HB, there is still a lack of relevant research methods and experimental data. The mechanism of bond effect of concrete on HB of blind bolt improved by welding Anchorage bar is not clear. At present, the research on tensile performance of blind bolt HB T- connection is mainly focused on the traditional T-type connection at home and abroad. However, there are few reports on the tensile properties of T-type connections formed from the back to back of two angle steel. The effect of bond effect and angle thickness of concrete on the tensile properties of blind bolt HB in T-joint is still lack of necessary experimental and theoretical study. Therefore, based on the deficiency of the above two researches, it is of great engineering significance to study the HB tensile properties of blind eye bolts from the component level and the structure level respectively. The main work of this paper is as follows: first, the tensile test of single blind bolt HB under various working conditions is carried out by using a new type of pull-out test device. Test variables include bolt type, concrete strength grade and whether to consider concrete bond effect. The failure modes and load-displacement curves of the specimens were obtained. The tensile properties of blind eye bolts HB under various working conditions were investigated from four aspects: stiffness, strength, ductility and fracture energy. The results show that the tensile properties of the improved blind bolt HB considering the bond effect of concrete are comparable to those of the ordinary high strength bolts of the same grade, which is more superior than that of the ordinary high strength bolts of the same grade. Secondly, 15 bolt axial tension finite element models are established by using finite element software Abaqus. The validity of the finite element model is verified by comparing the experimental results with the finite element simulation results. It is found that the finite element results are in good agreement with the experimental results and the experimental results are in good agreement with the literature, so as to prepare for the HB three-stage stiffness model of post-illiterate eye bolts. Third, based on the research of Nottingham University, Based on the stiffness relationship of spring series and parallel connection, the contribution of casing, central screw, anchor bar and concrete to external tension in initial stage is obtained by means of component method, which is based on the mechanism analysis of Type Agna Type B and Type C blind bolt HB. Based on the existing research on bolt stiffness and on the basis of a large number of finite element analysis and fitting, a three-segment stiffness model of blind eye bolt HB is proposed and its validity is verified. The results show that the HB three-stage stiffness model of blind bolt can be used to predict the stiffness of engineering structure. Fourth, the axial tensile test of seven bolt T-type connections formed through angle steel is carried out. The data of failure mode, load-displacement curve, strain-time curve and so on are obtained, and the stiffness and bearing capacity of the joint, such as bolt type, the thickness of column wall of steel tube, the thickness of angle steel, etc. Ductility and energy dissipation mechanism and influence law.
【学位授予单位】：烟台大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU391

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