索钢转换节点的磨损挤压性能研究

发布时间：2018-03-10 04:05

本文选题：索钢转换节点　切入点：摩擦磨损　出处：《北京交通大学》2013年硕士论文　论文类型：学位论文

【摘要】：在预应力张拉结构中,节点是连接结构各构件的关键部分。确保节点拥有良好的工作性能,才能保证预应力钢索与主体钢结构之间能够协同受力,索钢形成的结构体系具有一定的承载能力和稳定性。因而在工程实践领域,对预应力钢索与钢结构的连接节点开展相关力学性能的研究显得尤为重要。本文就索钢转换(连接)节点处,钢绞线钢索与连接件—钢索夹之间的摩擦磨损、接触挤压等问题进行深入地分析和探讨。本文的主要研究内容包括： 1.通过索钢转换节点的钢结构模型往复加载试验,研究了钢索与连接件之间在相对的摩擦滑移、不同的加载应力比以及不同接触材质条件下,表层索丝、Galfan镀层和连接件的损伤情况,以及钢索张拉力和摩擦力的变化规律； 2.通过索钢转换节点的有限元模型分析,研究了钢索与连接件之间在不同的接触条件下,表层索丝的应力分布,并通过应力放大系数ξ的取值大小,反映出不同的索钢接触条件下表层索丝损伤程度的差异。本文相关的研究结论如下： 1.若钢索处于在高张拉应力状态下,并与连接件之间存在往复的摩擦滑移,钢索表面的镀层会极易开裂,裂纹迅速地扩展汇聚并最终导致镀层的块状脱落,随后索丝钢基体表面暴露出来,索丝表面的损伤程度会明显加重； 2.向钢索与索夹接触面间加入不同的接触介质,可以得到往复加载后转换节点处钢索表层钢丝的损伤程度大小依次是：索孔内壁镀锌铝合金索钢直接接触加普通橡胶垫层加薄铝片垫层加耐磨橡胶垫层； 3.在往复加载过程中,钢索张拉力呈现出逐渐减小的变化趋势,张拉力损失在加载初期比较平稳,在加载中期,有一个稳定的增长的过程,在加载后期又趋于稳定,而钢索的摩擦力在整个加载过程中变化都比较平稳； 4.索钢接触处钢索表层索丝、Galfan镀层的损伤程度可与应力放大系数ξ建立对应关系。针对于索钢之间不同的接触条件,应力放大系数在1.10～1.25的范围内变化,在此范围内表层索丝的损伤程度变化幅度较大,而Galfan镀层损伤程度变化较为平稳。
[Abstract]:In the prestressed tensioning structure, the joint is the key part of the members of the connecting structure. To ensure that the joint has good working performance, the cooperative force between the prestressed steel cable and the main steel structure can be guaranteed. The structural system formed by cable steel has a certain bearing capacity and stability, so in the field of engineering practice, It is particularly important to study the mechanical properties of the connections between prestressed steel cables and steel structures. In this paper, the friction and wear between the steel strands and the connectors and clamps are discussed in this paper. Contact extrusion and other problems are deeply analyzed and discussed. The main contents of this paper are as follows:. 1. Through the reciprocating loading test of the steel structure model of the cable-steel transfer joint, the relative friction slip between the cable and the joint, the different loading stress ratio and the different contact material conditions are studied. The damage of Galfan coating and connectors, and the variation of tensile force and friction force of steel cable; 2. Through the finite element model analysis of the cable steel transfer joint, the stress distribution of the surface wire is studied under different contact conditions between the cable and the connector, and the value of the stress magnification factor 尉 is obtained. It reflects the difference of damage degree of surface wire under different contact conditions of cable and steel. The conclusions of this paper are as follows:. 1. If the cable is in the state of high tensile stress and there is reciprocating friction and slip between the cable and the connector, the coating on the surface of the steel cable will easily crack, and the cracks will spread rapidly and converge and eventually lead to the bulk fall off of the coating. Subsequently, the surface of cable steel matrix is exposed, and the damage degree of cable surface will be aggravated obviously. 2. The addition of different contact media to the contact surface between the cable and the cable clip, It can be obtained that the damage degree of the steel wire at the transfer node after reciprocating loading is as follows: direct contact of galvanized aluminum alloy cable steel with common rubber cushion and thin aluminum sheet cushion plus wear-resistant rubber cushion; 3. In the process of reciprocating loading, the tensile force of steel cable decreases gradually, the tension loss is stable at the beginning of loading, and in the middle of loading, there is a steady growth process, and then it tends to be stable at the later stage of loading. The friction force of the steel cable changes steadily during the whole loading process. 4. The damage degree of Galfan coating on the surface layer of cable can be related to stress magnification factor 尉. According to the different contact conditions between cables and steel, the stress magnification factor varies in the range of 1.101.25. In this range, the damage degree of surface wire changed greatly, while the damage degree of Galfan coating changed steadily.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU394

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