【作者】 李伟钊；

【导师】 王宗林；

【作者基本信息】 哈尔滨工业大学 ， 桥梁与隧道工程， 2008， 硕士

【摘要】 简支梁桥受力明确,构造简单,在工程中应用广泛。伴随着交通量的日益增长与桥梁结构服役期的延长,相当一部分桥梁结构老化、破损、性能下降,对这些桥梁进行损伤识别具有重要意义。结构动力损伤识别是土木工程中一个新兴的研究方向,尚未形成统一的求解理论与方法,仍处于发展的起步阶段。本文应用频域法中的曲率模态和柔度矩阵方法对简支梁桥结构的损伤定位问题进行研究,具体研究工作如下:(1)阐述桥梁结构损伤识别的意义、内容和方法,以及现阶段国内外在损伤识别领域的研究现状和研究成果,并且介绍了本文的主要研究内容。(2)本文对多种基于结构动力特性的损伤识别方法进行了分析和评述。对这些方法用于损伤识别的原理进行简要阐述,并分析了各自的特点及实际应用的局限性。(3)论述曲率模态分析的理论依据。基于20m五梁式简支梁实桥数值模型,通过弹性模量的减小来模拟损伤,通过ANSYS程序模拟得出的结构动力响应,损伤识别结果验证了曲率模态损伤识别指标对简支梁桥损伤识别的可行性、有效性和适用性。基于单损伤,讨论曲率模态损伤识别指标的抗噪声能力。(4)论述柔度法基本原理。采用16m五梁式简支空心板桥做为数值模型,通过弹性模量的减小来模拟损伤,用ANSYS计算模型的固有频率与振型,自编程序求得柔度矩阵及损伤识别指标,讨论柔度矩阵损伤识别指标对梁桥损伤识别的可行性、有效性和适用性。基于单损伤,讨论柔度损伤识别指标的抗噪声能力。(5)总结本文的研究内容和成果,并指出目前桥梁结构损伤识别有待解决的问题。更多还原

【Abstract】 Simple supported girder bridge is applied widely in the project because of it’s explicit stress and simple structure. Following the traffic freight volume increased unceasingly and extension of bridge structure service period, quite a part of them are ageing and wrecking and their performance are dropping. It is important to carries on the damage identification to these bridges. Structure damage identification based on dynamic signature has become a focus in the Civil Engineering. There are a lack of uniform theories and methods available, due to the not-so-mature developing period. This thesis contributes to a study on damage location of simple supported girder bridge through curvature mode methods and flexibility matrix methods belonging to the group of frequency-domain methods.The concrete research content of this thesis is as follows:(1) In addition to the significance, content and methods about the damage identification applied for bridge structures,some domestic and foreign information of research status and achievements in present stage is illustrated. The major work of this thesis are also introduced.(2) Various damage identification methods based on changes of vibration characteristics are summarized. The basic ideas of these methods are described, the feature of these methods and their limitations in practical application are discussed.(3) The theoretical basis is developed for the curvature modal analysis. In light of the numerical models of a simply supported 20m span 5-girder bridge. Damage simulated by reduction of modulus of elasticity and the structural dynamic response is computed by ANSYS. The identification results prove the feasibility, availability and applicability of damage identification criteria for curvature mode eigenvalue used for damage identification of simple supported girder bridge. In light of single damage, the anti-noise capactity of damage identification criteria is discussed.(4) The basic theory of flexibility matrix method is demonstrated. The model adopts simply supported 16m 5- hollow slab bridge,damage simulated by reduction of modulus of elasticity,the natural frequency and mode of vibration are computed by ANSYS ,flexibility matrix eigenvalue and damage identification criteria are computed by self design program. Discuss the feasibility, availability and applicability of damage identification criteria for flexibility matrix eigenvalue used for damage detection of girder bridge. In light of single-damage, the anti-noise capactity of damage identification criteria based on flexibility matrix eigenvalue is discussed.(5) The conclusion part is about a summation of the content and results derived from the research mentioned in the preceding chapters,as well as the problems should be solved in the damage detection of bridge.更多还原