大跨度连续刚构渡槽钢板伸缩节力学性能分析

发布时间：2018-07-10 05:53

本文选题：渡槽 + 伸缩节　；参考：《郑州大学》2017年硕士论文

【摘要】：由于山区远距离输水需求不断提高,高墩大跨连续刚构渡槽形式随之出现,相应增大了渡槽间伸缩缝的长度,传统渡槽伸缩缝在受力、形变和耐久性等方面已无法满足其长度增加的要求。为此,本文提出了一种新型的钢板伸缩节形式,设置在连续刚构渡槽与简支渡槽的端部连接处,并以黔中水利枢纽徐家湾渡槽连接段钢板伸缩节为研究对象,建立了结构几何非线性分析模型,分析了伸缩节在内水压力、轴向相对位移变位、横向相对位移变位以及竖向相对位移变位下伸缩节的应力水平,并依据有限元分析结果,对这种渡槽用伸缩节的力学性能进行了评价及参数优化分析,研究成果可作为相关工程设计、建造和应用的技术参考。主要研究内容包括以下四个方面:(1)结合渡槽伸缩节自身结构特点和受力特点,对渡槽用钢板伸缩节进行初步设计。(2)考虑结构几何非线性,对大型渡槽用钢板伸缩节进行有限元分析,分析在内压、位移荷载及二者组合作用下,各向应力大小及分布规律,并与美国膨胀节制造商协会标准(EJMA)计算值进行了对比。(3)对影响大型渡槽钢板伸缩节力学性能的参数进行分析,探究伸缩节各向应力随波形半径、波高、壁厚等波形参数变化规律;然后对伸缩节波形参数进行优化分析,同时建立两个相互独立的模型,分别施加轴向位移与内部压力,以伸缩节波高、壁厚、波纹半径为设计变量,以各向应力为结果变量,单元总体积为目标函数,确定减轻自重的优化尺寸。(4)在内压作用下,对有环箍约束伸缩节进行分析,采用接触单元模拟环箍与伸缩节的相互作用,提取接触波谷处的应力,并与未采用环箍约束伸缩节波谷处应力进行对比,结果表明环箍能有效的降低50%~70%波谷应力值。
[Abstract]:Due to the increasing demand for long-distance water delivery in mountainous areas, the form of continuous rigid frame aqueduct with high piers and long spans appears, which increases the length of expansion joints between aqueducts, and the traditional aqueduct expansion joints are subjected to stress. Deformation and durability can no longer meet the requirements of increasing its length. In this paper, a new type of steel plate expansion joint is proposed, which is arranged at the end joint between continuous rigid frame aqueduct and simply supported aqueduct, and takes the steel plate expansion joint of Xujiawan aqueduct connection section of Qianzhong Water Conservancy Project as the research object. The geometric nonlinear analysis model of the structure is established. The stress levels of the joints under the internal water pressure, the axial relative displacement, the lateral relative displacement and the vertical relative displacement are analyzed, and the results of finite element analysis are given. The mechanical properties of the expansion joint for aqueduct are evaluated and the parameters are optimized. The research results can be used as a technical reference for the design, construction and application of the aqueduct. The main research contents include the following four aspects: (1) considering the structural and mechanical characteristics of the aqueduct expansion joint, the preliminary design of the steel plate expansion joint for the aqueduct is carried out. (2) the geometric nonlinearity of the structure is considered. The finite element analysis of steel plate expansion joint used in large aqueduct is carried out to analyze the magnitude and distribution of stress in each direction under the action of internal pressure, displacement load and combination of the two. The results are compared with those calculated by the American Association of expansion Joint Manufacturers' Standards (EJMA). (3) the parameters affecting the mechanical properties of large aqueduct plate expansion joints are analyzed, and the stress in each direction of expansion joints is investigated with the wave radius and wave height. Then the waveform parameters of expansion joints are optimized and analyzed, and two independent models are established, which apply axial displacement and internal pressure respectively, and take the height of telescopic joints, wall thickness and corrugation radius as design variables. With the stress of each direction as the result variable and the total volume of the element as the objective function, the optimum size of reducing weight is determined. (4) under the internal pressure, the confined telescopic joints with ring hoop are analyzed, and the interaction between ring hoop and telescopic joint is simulated by contact element. The stress at the contact trough is extracted and compared with the stress in the trough of the telescopic joint without hoop constraint. The results show that the stress value of 50% 70% trough can be effectively reduced by the ring hoop.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TV672.3

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