面向健康诊断的斜拉桥模型损伤识别试验研究

发布时间：2018-10-09 18:18

【摘要】：随着时代的发展、科技的进步、材料的创新,斜拉桥逐渐向超大跨度方向发展,并成为大跨度桥梁的首选桥型之一。桥梁结构在长期运营条件及外界环境影响下,会出现各种各样损伤,若不及时发现和处理,将会导致结构的承载能力与耐久性降低甚至破坏,因而对结构的实时监测意义非凡。为建立健康监测系统,本文开展了以下几个方面工作:1.参照国内外大跨度斜拉桥资料,设计建造一座长6m的斜拉桥物理试验模型,该模型实现了可拆卸、可替换构件等功能,可模拟各种工况,针对性高,经济性好。并以该模型为载体建立结构健康监测系统。运用有限元软件ANSYS对该模型进行计算,初步确定了其静动力学特性,为试验的进行做了准备。2.模型试验。运用各种传感器设备采集各项数据。首先进行了主梁恒载与车辆指定点位静载试验,与有限元计算结果进行对比。其次将模型恢复至基准状态,在模型静载状态下对斜拉索损伤与主梁损伤进行试验。最后对模型进行车辆移动荷载下无损试验与斜拉索损伤试验。3.试验结果分析。数据表明:斜拉桥结构各项测试数据有规律变化,结构处于弹性工作状态;从主梁挠度、主梁应变与索力变化率等参数能够判断出结构的损伤,从多项参数分析比单项参数分析对损伤位置识别与损伤量识别更精确。本试验中从固有频率的改变量难以发现结构存在损伤。4.运用Wigner-Ville(WVD)分布交叉项对结构进行损伤识别。借助MATLAB时频分析工具箱设计MATLAB程序。分别用ANSYS有限元软件对简支梁进行损伤模拟,以及对斜拉桥模型进行斜拉索损伤模拟,结果表明该方法能够实现对损伤定位,但有待于进一步研究。
[Abstract]:With the development of the times, the progress of science and technology, the innovation of materials, cable-stayed bridges gradually develop to the direction of super-span, and become one of the preferred bridge types of long-span bridges. Under the influence of long-term operation conditions and external environment, there will be a variety of damage to bridge structure. If it is not found and dealt with in time, it will lead to the decrease or even damage of the bearing capacity and durability of the structure, so the real-time monitoring of the structure is of great significance. In order to establish a health monitoring system, this paper carried out the following aspects of work: 1. According to the data of long span cable-stayed bridge at home and abroad, the physical test model of 6 m long cable-stayed bridge is designed and constructed. The model realizes the functions of detachable and replaceable components, can simulate various working conditions, has high pertinence and good economy. The structural health monitoring system was established based on the model. The static and dynamic characteristics of the model are preliminarily determined by using the finite element software ANSYS. Model test. Use various sensor equipment to collect data. The dead load test of main beam and the static load test of vehicle at specified point are first carried out, and the results are compared with the finite element method. Secondly, the model is restored to the reference state, and the damage of the cable and the main beam is tested under the static load of the model. Finally, non-destructive test and cable damage test of the model under moving load are carried out. Analysis of test results. The data show that the test data of cable-stayed bridge vary regularly and the structure is in an elastic working state, and the damage of the structure can be determined from the parameters such as the deflection of the main beam, the change rate of strain and cable force of the main beam, etc. Multiple parameter analysis is more accurate than single parameter analysis in identifying damage location and damage quantity. In this experiment, it is difficult to find the damage of the structure from the change of natural frequency. The Wigner-Ville (WVD) distribution cross term is used to identify the damage of the structure. The MATLAB program is designed with the help of MATLAB time frequency analysis toolbox. ANSYS finite element software is used to simulate the damage of simply supported beam and cable damage to the model of cable-stayed bridge. The results show that the method can locate the damage, but it needs further study.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.27

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