钝体箱型断面双幅主梁气动干扰效应数值研究

发布时间：2018-06-12 00:47

本文选题：钝体箱型断面 + 双幅桥　；参考：《长安大学》2014年硕士论文

【摘要】：随着西北地区经济与交通急剧发展，，双幅连续钢构桥在设计时越来桥越受到设计者的青睐。而在西北地区，桥梁多跨越深谷沟壑，在此地形上的桥梁受到风的影响较为严重。连续刚构桥多采用钝体箱型断面，气动性能相比流线型扁平梁及桁式梁桥差，两幅桥断面之间的气动干扰更为明显。因此针对钝体箱型断面之间气动力系数的研究具有实际意义。本文结合西北地区某一典型双幅连续钢构桥采用数值模拟的方法计算得到各控制断面的三分力系数，并转化为干扰因子定量分析其气动干扰效应。分析计算结果得到：双幅上下游桥面尤其下游桥面相对单幅桥面之间存在较为明显的气动干扰效应。单幅桥面主梁宽度一定高度不同时，阻力系数随宽高比的增大而减小，而升力系数、扭矩系数并无统一规律。对于双幅桥面，随断面高度增加，阻力系数的干扰效应影响增强，而升力系数及扭矩系数影响随断面高度变化规律不明显，但相对于单幅断面而言，总体上下游桥面的绕流气动干扰效应较为显著。因此，在该类钝体箱型截面连续钢构桥设计时，双幅主梁之间的气动干扰效应不可忽略，设计时针对典型断面之间的干扰必须进行专门的研究分析。在计算结果基础上，本文采用测压方法得出计算断面压力系数均值和根方差值的分布图，并对关键测点做频谱分析，结合各个工况下的压力云图和涡量图从微观层面对双幅桥面间的气动干扰效应进行解释。
[Abstract]:With the rapid development of economy and traffic in Northwest China, the design of two-piece continuous steel bridges is more and more popular with designers. In Northwest China, bridges often span deep valleys and gullies, and bridges in this terrain are seriously affected by wind. The continuous rigid frame bridges usually use blunt body box section. The aerodynamic performance of continuous rigid frame bridges is worse than that of streamlined flat beams and truss girder bridges, and the aerodynamic interference between the two sections is more obvious. Therefore, it is of practical significance to study aerodynamic coefficients between blunt body box sections. In this paper, the three-point force coefficients of each control section are calculated by numerical simulation method combined with a typical double-piece continuous steel bridge in Northwest China. The aerodynamic interference effect is analyzed quantitatively by transforming it into a disturbance factor. The results of analysis and calculation show that there is obvious aerodynamic interference between the upper and downstream deck, especially between the downstream deck and the single deck. The resistance coefficient decreases with the increase of the ratio of width to height, but the lift coefficient and torque coefficient have no uniform rule. For double deck, the interference effect of drag coefficient increases with the increase of cross-section height, but the influence of lift coefficient and torque coefficient on cross-section height is not obvious. As a whole, the aerodynamic interference around the upper and lower deck of the bridge is obvious. Therefore, in the design of this kind of continuous steel bridge with blunt body box section, the aerodynamic interference effect between the two main beams should not be ignored, and the interference between typical sections must be studied and analyzed in the design. In this paper, the distribution map of the mean and root variance of the cross section pressure coefficient is obtained by using the method of pressure measurement, and the spectrum analysis of the key measuring points is made. Combined with the pressure cloud map and vorticity diagram under various working conditions, the aerodynamic interference effect between the two bridge decks is explained from the microscopic level.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3

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