基于小波分析和移动荷载作用的连续梁桥损伤识别研究

发布时间：2018-06-14 07:45

本文选题：连续梁桥 + 损伤识别　；参考：《郑州大学》2016年硕士论文

【摘要】：桥梁工程在运营过程中,往往会因各种损伤病害而影响桥梁的安全和行车的舒适性,为此对桥梁损伤进行及时的诊断和处理是十分必要的。但一些传统的结构损伤检测方法,存在各种缺陷,比如需要中断交通,布置大量传感器以及检测诊断过程复杂等。基于运营荷载下桥梁动力响应的检测方法解决了上述不足,但目前仅在简支梁桥等简单结构中的研究较多,而在连续梁桥等多跨复杂结构中的研究较少。为此,本文以连续梁桥为分析对象,采用移动荷载作为激励,对基于移动荷载下动力响应和连续小波变换的连续梁桥损伤指标和识别方法进行了深入研究,分析研究结果表明所提出的损伤指标和损伤识别方法具有很好的识别效果。本文的主要研究内容和成果包括以下四个方面:1.针对传统桥梁结构损伤识别方法的不足,重点分析了基于移动荷载作用的桥梁结构损伤识别方法,并对连续梁桥损伤识别的研究历史和现状进行了总结和归纳。2.从理论上推导了移动荷载作用下无损伤和有损伤两跨连续梁的跨中动力响应,从理论上说明了任一跨的结构损伤对结构其他跨的响应都有影响,并给出了其影响程度,说明了通过连续梁桥任意跨的响应进行损伤识别的可行性。3.提出了基于桥梁结构任一点加速度响应差的连续梁桥损伤识别方法。具体方法为:采集得到无损伤和有损伤连续梁桥在移动荷载下某点的加速度时程,然后对加速度差值进行连续小波变换,利用小波变换系数峰值识别损伤位置,并对损伤程度进行估计。通过三跨变截面连续梁桥数值模拟验证了方法的有效性,分别研究了多处损伤、移动荷载速度、损伤程度以及噪声对损伤识别效果的影响。研究结果表明损伤识别方法受荷载移动速度影响较大,在约40km/h速度下、低于5%噪声水平时可以准确识别出各损伤位置。4.对连续梁桥的加速度响应求对数能量,再利用小波包对其进行分解和重构,提出了对数加速度能量差小波包样本熵(SPLE)结构损伤指标。也通过三跨变截面连续梁桥数值模拟验证了方法的有效性,利用SPLE损伤指标对桥梁结构损伤位置和程度进行识别,并分析了SPLE损伤指标的噪声鲁棒性。分析结果表明,SPLE指标不仅能识别出损伤,而且具有更好的抗噪性能。
[Abstract]:During the operation of bridge engineering, the safety of bridge and the comfort of traffic are often affected by various damage diseases. Therefore, it is necessary to diagnose and deal with bridge damage in time. However, some traditional structural damage detection methods have various defects, such as the need to interrupt traffic, arrange a large number of sensors and detect the damage. The detection method of the bridge dynamic response based on the operation load has solved the above shortcomings, but at present, there are only a few simple structures such as simple beam bridge and other simple structures, but there are few studies in the multi span complex structures such as continuous beam bridge. The damage index and recognition method of continuous beam bridge under moving load and continuous wavelet transform are deeply studied. The analysis results show that the damage index and damage identification method have good recognition effect. The main research contents and results of this paper include the following four aspects: 1. for the traditional bridge structure The damage identification method is insufficient. The damage identification method of bridge structure based on moving load is emphatically analyzed. The history and present situation of the damage identification of continuous beam bridge are summarized and summarized..2. has deduced the dynamic response of the two span continuous beam without damage and damage under the action of moving load. It is clear that the structural damage of any span has an influence on the response of the other span of the structure, and gives its degree of influence. It illustrates the feasibility of the damage identification by the response of the arbitrary span of the continuous beam bridge.3.. The method of damage identification of continuous beam bridge based on the acceleration response of any point of the bridge structure is proposed. The acceleration time history of the damaged and damaged continuous beam bridge at a certain point under the moving load, then the continuous wavelet transform is carried out on the acceleration difference value, the damage position is identified by the peak value of the wavelet transform coefficient and the damage degree is estimated. The effectiveness of the method is verified by the numerical simulation of three cross section continuous beam bridge, and the multiple damage is studied respectively. The effect of moving load speed, damage degree and noise on damage identification results. The results show that the damage identification method is greatly influenced by the moving speed of load. At the speed of about 40km/h, the damage location.4. can be accurately identified for the logarithmic energy of the acceleration response of the continuous beam bridge, and then the wavelet packet is used. It is decomposed and reconstructed, and the damage index of the logarithmic acceleration energy difference wavelet packet sample entropy (SPLE) is proposed. The effectiveness of the method is verified by the numerical simulation of three cross section continuous beam bridge. The damage location and degree of the bridge structure is identified by the SPLE damage index, and the noise robustness of the SPLE damage index is analyzed. The results show that the SPLE index not only can identify the damage, but also has better noise immunity.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U446

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