异形梁桥偏载系数分析及损伤识别方法研究

发布时间：2018-01-13 00:23

本文关键词：异形梁桥偏载系数分析及损伤识别方法研究　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着我国经济快速增长与城市化进程的不断推进,城市交通需求不断增大,给城市交通运输提出了新的挑战。为了适应城市交通流的不断增长及地形空间的局限,异形桥梁作为主线与匝道的连接结构,得到了不断应用,极大地解决了繁重的城市交通问题。但异形桥梁结构空间受力复杂,现行设计规范及计算理论对该型桥梁尚未做出详细规定,设计理论亟待完善。偏载系数作为车辆偏载时对桥梁整体受力影响的分析参数,现有偏载系数分析方法存在局限性,提出适用于异形桥梁的偏载系数计算方法对提高结构的设计安全性尤为重要。此外,在重载交通作用下,异形桥梁结构极易出现损伤,给人员和车辆的出行带来安全隐患。因此,完善异形桥梁结构的设计方法,及时、有效识别异形桥梁结构损伤,对保障该型桥梁安全运营具有重要意义。本文依托吉林省交通厅科技项目《异形预应力混凝土桥梁受力特性分析及设计方法研究》,选取分叉型和渐变型两类典型的异形箱梁桥作为研究对象,通过数值仿真分析了设计参数对偏载系数的影响。针对分叉桥跨在复杂受力条件下的损伤状态,提出了具有较高准确性的损伤识别方法,具体研究内容如下:1、对现有直线桥梁设计理论与偏载系数计算方法进行了概述,对比分析了各方法的适用条件和优缺点。阐述了有限元数值仿真方法和响应曲面法在异形梁桥偏载系数计算分析中的适用性,为后续研究提供了理论依据。2、针对异形梁桥设计参数对偏载系数的影响,基于Box-Behnken响应曲面方法计算分析了偏载系数与设计变量间的定量影响关系。以跨径、箱梁截面宽度和高度、匝道半径、暗横梁刚度作为响应曲面法输入值,以偏载系数为响应输出值,确定了设计参数对偏载系数的影响分析方案。对各参数组合下的异形梁桥进行数值仿真,提取控制截面测点的应力、挠度来计算典型异形梁桥的偏载系数,得到了各设计参数对偏载系数的影响规律。通过建立设计变量与偏载系数之间的多项式函数关系,为实际工程偏载系数计算提供参考。3、基于模态曲率差与模糊推理理论,提出了异形梁桥分叉桥跨的损伤识别方法。将振型数据进行二次差分,计算模态曲率值,通过损伤前后的模态曲率差进行损伤位置识别。在此基础上,以损伤位置节点模态曲率差为损伤程度识别指标,采用隶属度函数对其进行模糊化,构建损伤识别模糊规则库,通过测试样本与模糊规则库的模式匹配,实现损伤程度识别。数值仿真损伤识别结果表明,基于模糊曲率差与模糊推理的损伤识别方法能够准确识别分叉桥跨的既有损伤,验证了该方法在异形梁桥损伤识别中的有效性。
[Abstract]:With the rapid growth of China's economy and city development, city traffic demand increases unceasingly, put forward the new challenge to the city transportation. In order to adapt to the growing city traffic and terrain space limitation, special-shaped bridge connecting structure as main line and ramp, has been continuously applied, greatly solve the city the heavy traffic problems. But the special-shaped bridge structure spatial stress is complex, the bridge has not yet made with current design specifications and calculation theory, design theory needs to be improved. Parameter analysis of partial load coefficient as the partial load vehicles on the bridge when the overall stress effect, the existing partial load coefficient analysis method has limitations, calculation method the partial load coefficient is proposed for special-shaped bridge is very important to improve the design of the safety of the structure. In addition, under heavy load, special-shaped bridge structure prone to damage Injury, security risks to personnel and vehicle travel. Therefore, to improve the design method, special-shaped bridge structure and special-shaped bridge structure damage identification effectively, to guarantee the safe operation of the bridge type has important significance. This paper relies on the project "Jilin province transportation hall shaped prestressed concrete bridge force analysis and Design Method Study on the selection of irregular box >, forked and graded two typical girder bridge as the research object, effects of design parameters on partial load coefficient is studied by numerical simulation. The bifurcation bridge in complex stress conditions by injury, the damage identification method has high accuracy, the specific contents are as follows 1, the existing design theory of linear bridge and partial load coefficient calculation method are summarized, compared and analyzed the applicability of the methods and the advantages and disadvantages are expounded. The finite element numerical simulation method And the response surface method in special-shaped bridge eccentric load coefficient calculation applicability analysis, provides a theoretical basis for further research on.2, special-shaped bridge design parameters on the impact of partial load coefficient, Box-Behnken response surface method to analyze the quantitative effects of partial load coefficient and the relationship between the design variables. Based on the calculation to the span, box beam width and height, ramp radius, dark beam stiffness as the response surface method to input value, partial load coefficient of response output value, to determine the influence of design parameters on partial load coefficient analysis method. The parameters of beam bridge under the combination of numerical simulation, extraction and control points of section stress. To calculate the deflection of eccentric load coefficient of typical special-shaped bridge, get the design parameters on the influence of eccentric load coefficient. The polynomial function by establishing a relationship between the design variables and partial load coefficient, eccentric load coefficient for practical engineering Calculation of reference.3, based on the modal curvature difference and fuzzy reasoning theory, put forward the method of damage identification of beam bridge bridge. The bifurcation mode data for the two time difference calculation, modal curvature value, the modal curvature difference before and after damage damage location identification. On this basis, the damage location node mode as the curvature damage identification index, using the membership function of the fuzzy, construction damage identification Fuzzy rule base, through the test sample and the fuzzy rules for pattern matching, to achieve the recognition of the damage degree. The numerical simulation results show that the damage identification, damage identification method of fuzzy curvature and fuzzy reasoning can accurately identify the bifurcation of the bridge is based on the damage, to verify the validity of the method in damage identification of beam bridge.

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U446

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