一种粘性阻尼系统的模型修正方法研究

发布时间：2018-02-10 15:17

本文关键词： 模型修正阻尼模型正交模型正交模态复模态　出处：《南京航空航天大学》2014年硕士论文　论文类型：学位论文

【摘要】：近几十年来，以提高有限元仿真计算精度为目的有限元修正技术受到了科技和工业应用领域的广泛关注且得到了迅猛发展。本文在正交模型-正交模态修正方法的基础上，提出了三种模型修正方法。对比例阻尼模型和粘性阻尼模型进行模型修正过程中，讨论三种方法的优缺点，选出最优修正方法。研究参数选取对该方法修正结果的影响，并用该方法对工程实际结构进行修正。具体内容如下：本文简述了几种有限元模型修正的经典方法，讨论各种修正方法的优劣势，并提出选择模型修正方法的基本原则；针对实际模型含有一般粘性阻尼以及避免数值奇异等问题，提出了三种修正方法，即含阻尼正交模型-正交模态修正方法（DCMCM）、含阻尼正交模型-正交模态改进修正方法(DICMCM)、含阻尼正交模型-正交模态反乘改进修正方法(DICMCM反乘法)。经数值算例验证，含阻尼正交模型-正交模态改进修正方法可以解决上述问题且修正结果精度较高。本文选取不同组试验数据，验证选取不同阶模态下含阻尼正交模型-正交模态改进修正方法（DICMCM）修正结果的准确性；选取不同数量试验模态对修正结果影响最大，在修正过程中应选取尽量多的试验数据，以获得更精确的修正结果；迭代二次修正对修正结果影响最小，可以看出本方法无须迭代，，节省计算时间；选取等量不同阶次试验数据不影响修正结果。本文用含阻尼正交模型-正交模态改进修正方法（DICMCM）对某钢架结构进行了模型修正，验证其是否满足工程结构动力学分析的要求。结果表明：修正后的结构有限元模型仿真计算结果与试验测试结果吻合，修正后频率相对误差均在3%以下。因此本文所提出的模型修正方法在工程中具有实际应用价值。
[Abstract]:In recent decades, the technology of finite element correction, aiming at improving the accuracy of finite element simulation, has been paid more and more attention in the fields of science, technology and industry. This paper is based on the orthogonal model-orthogonal mode correction method. In the process of model modification of proportional damping model and viscous damping model, the advantages and disadvantages of the three methods are discussed, and the optimal correction method is selected. The method is used to modify the actual structure of the project. The specific contents are as follows:. In this paper, several classical methods of finite element model modification are briefly introduced, the advantages and disadvantages of these methods are discussed, and the basic principles of selecting model modification methods are put forward, aiming at the problems of general viscous damping and avoiding numerical singularity in practical models. Three correction methods are proposed. That is, the damped orthogonal model-orthogonal mode correction method, the damped orthogonal model-orthogonal mode modification method, the damped orthogonal model-orthogonal mode inverse multiplication modified method, the DICMCM inverse multiplication method and the numerical example. The damped orthogonal model-orthogonal mode modified method can solve the above problems, and the accuracy of the modified results is high. In this paper, we select different groups of test data to verify the accuracy of the modified results of the damped orthogonal model-orthogonal mode modified method (DICMCM) under different modes, and select different experimental modes to have the greatest influence on the correction results. The experimental data should be selected as much as possible in the process of correction to obtain more accurate correction results, the second iteration correction has the least influence on the correction results, it can be seen that this method does not need iteration and saves calculation time. Selecting the same number of different order test data does not affect the correction results. In this paper, the damped orthogonal model-orthogonal mode modification method (DICMCM) is used to modify the model of a steel frame structure. The results show that the simulation results of the modified finite element model are in agreement with the experimental results. The relative error of the modified frequency is less than 3%, so the model modification method proposed in this paper has practical application value in engineering.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535.1

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