震后大型球罐—支撑体系的相关力学问题研究

发布时间：2018-11-29 08:41

【摘要】：由于近年来中国地震频繁发生,导致很多震区球形储罐损坏,产生很多结构缺陷。由于这些结构缺陷属于小变形,肉眼难以发觉,容易引起人们的麻痹大意。而球罐存储的物质一般具有易燃、易爆、剧毒、腐蚀等特性,属于重大危险源,一旦事故发生,将造成严重后果,开展震后含缺陷球罐-支撑体系的相关力学问题研究,对此类重要结构的安全运营及可靠性分析具有重要意义。本文针对上述情况,以成都地区某经历汶川、雅安地震后的某大型燃气球罐为对象,进行了如下研究工作：首先,对该球罐进行现场模态试验,获得球罐的自振频率；并依据球罐初始设计图纸建立有限元模型,对其进行模态分析；依据GB12337规范计算该球罐的固有频率。并对三种方式获得的球罐自振频率对比分析讨论,获得了球罐的初步结构损伤情况,并通过现场试验测试获得球罐实测固有频率,验证了有限元模型的正确性。然后,国内首次创新性的对震后球罐缺陷进行精细测量,获得球罐的支柱沉降、支柱垂直度变化及球罐中心与支柱拟合中心的偏移等缺陷数据。建立包含上述缺陷的精细有限元模型,对含缺陷球罐模型进行力学分析,获得震后球罐的安全性能,并与不含缺陷球罐模型进行结果对比,讨论了缺陷对球罐安全性能的影响。对球罐的缺陷进行容限分析,找到在现有震级下球罐正常运行所能接受的最大结构变形,为球罐的安全生产提供一定的借鉴。最后,分别对含缺陷和不含缺陷球罐进行反应谱分析。大型球罐-支撑体系属于一类特殊装备结构,其抗震特性具有较高要求。介绍了单自由度反应谱分析方法的一般思想,给出了三维反应谱的基本理论,采用通用商业程序对大型球罐-支撑体系进行抗震性能分析,获得了球罐-支撑体系的地震反应谱响应,并讨论了缺陷对球罐-支撑体系的抗震性能影响。
[Abstract]:Due to frequent earthquakes in China in recent years, many spherical storage tanks have been damaged and many structural defects have been caused. Because these structural defects belong to small deformation, it is difficult for the naked eye to detect them. However, the materials stored in spherical tanks are generally flammable, explosive, highly toxic, corrosive and so on. Once an accident occurs, it will cause serious consequences. The mechanical problems related to the spherical tank-bracing system containing defects after the earthquake will be studied. It is of great significance for the safety operation and reliability analysis of such important structures. In this paper, a large gas spherical tank after Wenchuan and Ya'an earthquake in Chengdu area was studied as follows: firstly, the field modal test was carried out to obtain the natural frequency of the spherical tank; The finite element model is established according to the initial design drawing of the spherical tank, and the modal analysis is carried out, and the natural frequency of the spherical tank is calculated according to the GB12337 code. By comparing and analyzing the natural vibration frequencies of the spherical tanks obtained by three methods, the initial structural damage of the spherical tanks is obtained, and the measured natural frequencies of the spherical tanks are obtained by field test, which verifies the correctness of the finite element model. Then, for the first time, the defect data of spherical tank are obtained, such as the settlement of spherical tank, the change of perpendicularity and the deviation between the center of spherical tank and the fitting center of the spherical tank. The fine finite element model including the above defects is established, and the mechanical analysis of the spherical tank model with defects is carried out, and the safety performance of spherical tank after earthquake is obtained. The results are compared with those of the spherical tank model without defect, and the influence of defects on the safety performance of spherical tank is discussed. By analyzing the defects of spherical tank, the maximum structural deformation of spherical tank can be found under the existing earthquake magnitude, which can provide some reference for the safe production of spherical tank. Finally, the reaction spectra of spherical tanks with and without defects were analyzed. Large spherical tank-bracing system belongs to a class of special equipment structure, its seismic characteristics have higher requirements. The general idea of single degree of freedom response spectrum analysis method is introduced, and the basic theory of three-dimensional response spectrum is given. The seismic performance of large spherical tank braced system is analyzed by general commercial program. The seismic response spectrum of spherical tank-braced system is obtained, and the effect of defects on seismic performance of spherical tank-braced system is discussed.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE972

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