基于测试数据的桥梁模型修正方法研究

发布时间：2018-02-15 04:00

本文关键词： 有限元模型修正荷载试验测试数据目标函数　出处：《重庆交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国公路与铁路等基础建设的开展,我国桥梁规模与数量越来越大。不论是新建的桥梁还是在役桥梁,它们的承载能力总是受到桥梁研究者以及相关部门的关注。成桥荷载试验与加固后桥梁的荷载试验是检测桥梁承载力的有效手段。然而,荷载试验时间比较长,且需要封闭交通,对道路畅通造成不利影响。根据图纸设计参数建立的有限元模型是荷载试验布载方案制定以及测试数据对比的重要参照,有限元模型的计算值与荷载试验的测试值存在比较大的差异。本文通过研究有限元模型的修正方法,构造不同的目标函数,在ANSYS有限元平台,通过一个工字钢简支梁的数值算例,通过人为对其相关参数的折减造成数值模型的损伤,求出损伤后有限元模型的特定结点的位移值以及频率作为测试值,通过测试值构造不同目标函数,对比分析基于静力单目标函数、基于动力单目标函数以及联合静动力目标函数对模型修正效果,通过此数值算例,验证此有限元模型修正方法的正确性。后续章节以寂静特大桥荷载试验为工程背景,用荷载试验测试值构造上述目标函数,分别对有限元模型中主梁与桥墩的相关参数进行修正,修正后的有限元模型计算值与测试数据之间的误差有明显的减小,与测试数据较之修正前更加吻合,修正后的模型更能体现实桥的静动力特征。本文结尾探究了大跨度柔性悬索桥青草背长江大桥有限元模型修正方法,以荷载试验中工况下主梁测点挠度测试数据构造目标函数,对青草背长江大桥有限元模型中主梁的弹性模量和抗弯惯性矩以及截面面积、主缆的等效弹模修正,然后以有限元模型主梁挠度计算值与测试数据对比,评价基于主梁测点挠度测试值构造的单目标函数的修正方法。经过数值算例与实桥对有限元模型修正方法的验证,说明修正后的模型比按照图纸设计参数建立的有限元模型分析结果更接近荷载试验测试数据,更能反映桥梁的实际状况,修正后的模型可以为桥梁服役期的养护运营提供参考,可通过修正后的有限元模型对该桥进行荷载承载力评定。
[Abstract]:With the development of highway and railway infrastructure in China, the scale and number of bridges in our country are becoming larger and larger. Their bearing capacity is always concerned by bridge researchers and relevant departments. Bridge load test and strengthened bridge load test is an effective means to detect the bearing capacity of bridge. However, the load test time is relatively long. The finite element model established according to the drawing design parameters is an important reference for the formulation of load distribution scheme and the comparison of test data. There is a big difference between the calculated value of finite element model and the test value of load test. In this paper, by studying the modification method of finite element model, different objective functions are constructed. Through a numerical example of a simply supported I-beam, the damage of the numerical model is caused by the reduction of the relevant parameters, and the displacement value and frequency of the finite element model after the damage are calculated as the test values. Different objective functions are constructed by test values, and the effect of model correction based on static single objective function, dynamic single objective function and combined static and dynamic objective function is compared and analyzed. The validity of the finite element model modification method is verified. In the following chapters, the above objective function is constructed by using the load test results of the Silent Super large Bridge as the engineering background. The relative parameters of the main beam and pier in the finite element model are revised respectively. The error between the calculated value of the modified finite element model and the test data is obviously reduced, which is more consistent with the test data than before. The modified model can better reflect the static and dynamic characteristics of the real bridge. At the end of this paper, the finite element model correction method of the Qingcao-back Yangtze River Bridge with long span flexible suspension bridge is explored. The objective function is constructed from the deflection test data of the main beam measured points under the load test conditions. The elastic modulus, bending moment of inertia and cross-section area of the main girder and equivalent elastic modulus of the main cable in the finite element model of the Qingcaobei Yangtze River Bridge are revised, and then the calculated values of the deflection of the main girder of the finite element model are compared with the test data. The correction method of single objective function based on deflection test value of main beam measuring point is evaluated, and the finite element model modification method is verified by numerical example and real bridge. It shows that the modified model is closer to the test data of load test than the finite element model established according to the parameters of drawing design, and it can reflect the actual condition of the bridge, and the modified model can provide reference for the maintenance and operation of the bridge service period. The load bearing capacity of the bridge can be evaluated by the modified finite element model.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U446

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