考虑混凝土粘结效应的盲眼螺栓抗拉性能研究

发布时间：2018-05-10 19:29

本文选题：盲眼螺栓 + 粘结效应　；参考：《西南交通大学学报》2017年05期

【摘要】：为了研究混凝土的粘结效应对盲眼螺栓抗拉性能的影响,采用抗拉装置,对预埋于钢管混凝土的盲眼螺栓进行了抗拉试验.首先得到各种工况下试件的破坏模式和荷载-位移关系曲线;其次对各种工况下试件的破坏模式和荷载-位移关系曲线进行比较分析,得到有无混凝土以及不同混凝土强度等级对盲眼螺栓初始刚度、强度和延性的影响;最后分析考虑混凝土粘结效应后盲眼螺栓的抗拉受力机理,并提出了改良盲眼螺栓的合理措施.研究结果表明:混凝土的粘结效应改变了盲眼螺栓的抗拉传力机理,使其整体受力从套管转移到中心螺杆,从而使其破坏模式由套管提前破坏失效转化成中心螺杆强度破坏;混凝土强度等级对盲眼螺栓刚度有显著影响,混凝土强度从C30提高至C50时,其初始刚度由15.1%提高至35.7%,其屈服后刚度也分别提高了1.27和1.64倍;盲眼螺栓的抗拉屈服强度和延性主要由套管的性质决定,抗拉极限强度则取决于中心螺杆的承载力,混凝土的强度等级对其无影响.
[Abstract]:In order to study the effect of concrete bond effect on the tensile properties of blind eye bolts, the tensile test was carried out on the blind bolt buried in the concrete filled steel tube by tensile device. The failure mode and load displacement curve of the specimen under various working conditions were first obtained. Secondly, the failure mode and load displacement relation of the specimens under various working conditions were obtained. The effect of concrete and different concrete strength grades on the initial stiffness, strength and ductility of blind eye bolts is obtained. Finally, the mechanism of tensile stress resistance of blind eye bolts after the concrete bond effect is considered, and the rational measures for improving blind eye bolts are put forward. The results show that the bond effect of concrete is the effect of concrete. The tensile force mechanism of blind eye bolts should be changed to make the whole force transferred from the casing to the central screw, so that the failure mode of the bolt should be transformed from the early failure of the casing to the strength of the central screw; the strength grade of the concrete has a significant influence on the stiffness of the blind eye bolt. The initial stiffness of the concrete is 15.1% when the strength of concrete is raised to C50. The yield strength and stiffness of the blind eye bolt are increased by 1.27 and 1.64 times respectively to 35.7%. The tensile yield strength and ductility of blind eye bolts are mainly determined by the properties of the casing, and the ultimate tensile strength depends on the bearing capacity of the central screw, and the strength grade of the concrete has no effect on it.

【作者单位】：烟台大学土木工程学院;湖南大学土木工程学院;湖南省建筑工程集团总公司;
【基金】：国家自然科学基金资助项目(51408212,51478407)
【分类号】：TU37

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