简支梁桥整体状态评估和基于宏应变损伤识别方法研究

发布时间：2018-06-05 11:07

本文选题：简支梁 + 宏应变　；参考：《苏州科技学院》2015年硕士论文

【摘要】：中小简支梁桥是最常见的桥梁结构形式,在各种环境因素的作用下,桥梁结构有可能出现各种各样的损伤或者其本身在建造过程中由于施工不当造成损伤,如何识别出损伤,判断损伤的位置、损伤程度及剩余寿命成为损伤识别领域研究的热点,国内外学者对此进行了大量的研究。布拉格光纤光栅应变传感器是一种新型的传感器,相比于传统的应变片具有可靠性高、抗干扰能力强、体积小质量轻便于安装、测量精度高、范围大、传感信号可远距离,多通道传输的优点,虽然目前对于FBG传感器在长大跨桥梁方面的应用研究已取得了一定的成果,但是对于更加常见的中小简支梁桥的健康监测及损伤识别缺乏一定的研究。宏应变是测量标距范围内的平均应变,测量范围远大于点应变,仅需布置少量的传感器就能精确识别出损伤,而且应变类参数损伤识别指标相比位移类参数损伤识别指标精度更高,因此,以宏应变为基础的损伤识别参数指标得到越来越多的重视。本文主要以苏州市最为常见的简支梁桥为损伤识别对象,介绍了以外观调查法为基础的简支梁桥整体状态评估方法,以荷载试验为原理、ABAQUS数值仿真,分析了宏应变类参数损伤识别指标能否识别出损伤,主要工作如下:1、回顾了国内外结构损伤识别研究现状及损伤识别面临的挑战,介绍了FBG光纤光栅传感器以及损伤识别方法;2、以苏州市常见的中小简支梁桥为对象,总结了基于外观调查法和荷载试验的简支梁桥状态评估流程,为类似的工程提供工程借鉴。3、基于ABAQUS有限元软件建立了单根简支组合梁和以实桥为基础的多根简支组合梁,构造两种损伤因子,以荷载试验为原理,分析了基于宏应变参数的损伤识别指标能否识别出损伤;4、通过小比例工字钢简支梁试验,验证了宏应变参数识别指标的有效性本文的研究内容侧重于如何借助外观调查法、荷载试验以及宏应变损伤识别参数对苏州市中小简支梁桥进行损伤识别,并用ABAQUS建模,构造两种损伤因子分析了宏应变损伤参数能够很好识别出损伤。
[Abstract]:The small and medium-sized simply supported beam bridge is the most common bridge structure form. Under the action of various environmental factors, the bridge structure may appear various kinds of damage or the damage caused by its own improper construction process, how to identify the damage. Judging the location, extent and residual life of damage has become a hot spot in the field of damage identification, and scholars at home and abroad have done a lot of research on it. Fiber Bragg grating strain sensor is a new kind of sensor. Compared with the traditional strain gauge, it has high reliability, strong anti-interference ability, small volume, light mass, easy installation, high measurement precision, wide range, and the sensor signal can be remote. The advantages of multi-channel transmission, although the application of FBG sensors in long-span bridges has made some achievements, but the more common small and medium-sized simply supported bridge health monitoring and damage identification lack of some research. Macro strain is the average strain in the range of measurement distance. The measurement range is much larger than the point strain, and only a small number of sensors can be deployed to accurately identify the damage. Moreover, the damage identification index of strain parameter is more accurate than that of displacement type parameter. Therefore, more and more attention has been paid to the damage identification parameter index based on macro strain. This paper mainly takes the most common simply supported beam bridge in Suzhou as the object of damage identification, and introduces a simple supported beam bridge whole state evaluation method based on the appearance investigation method. The Abaqus numerical simulation is carried out on the principle of load test. In this paper, the damage identification index of macro strain parameter is analyzed. The main work is as follows: 1. The research status of damage identification at home and abroad and the challenge of damage identification are reviewed. FBG fiber Bragg grating sensor and damage identification method are introduced in this paper. Taking the common small and medium-sized simply supported beam bridges in Suzhou as an example, the state evaluation flow of simple supported beam bridges based on appearance investigation and load test is summarized. Based on ABAQUS finite element software, a single simply supported composite beam and multiple simply supported composite beams based on real bridge are established to construct two kinds of damage factors, and the principle of load test is used to construct two kinds of damage factors. This paper analyzes whether damage identification index based on macro strain parameter can identify damage No. 4, and validates the validity of macro strain parameter identification index by small ratio simple beam test of I-beam. The research content of this paper focuses on how to make use of external appearance investigation method. Load tests and macro strain damage identification parameters are used to identify the damage of small and medium sized simply supported beam bridges in Suzhou. Two damage factors are constructed and analyzed by ABAQUS model. The damage can be well identified by macro strain damage parameters.
【学位授予单位】：苏州科技学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446

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