随机地震激励下塔式起重机结构动态响应分析

发布时间：2018-03-09 07:57

本文选题：塔式起重机　切入点：随机振动　出处：《西南交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：伴随着现代科学技术和建筑结构设计的迅猛发展,塔式起重机的施工高度越来越高。我国是一个多地震国家,塔机作为一种高耸设备,其重心高、质量分布不均匀、柔性大,一旦遭受地震破坏,不仅会造成巨大的生命财产损失,而且会影响抗震救灾的进程,甚至产生次生灾害,因此塔机的地震响应不容忽视。目前对塔机的研究多集中在模态分析、稳定性分析和疲劳分析,而对塔机的随机地震响应分析仍处于探索阶段,尚未形成完善的抗震分析理论及计算方法,所以对塔式起重机结构的随机地震分析有一定的现实意义,其计算结果可供工程实践参考。论文的主要研究工作包括以下几个方面：1.利用有限元分析软件ANSYS,根据塔式起重机工程实际情况建立有限元模型,对塔机结构进行静力分析,得到应力分布情况,并对塔机进行强度、刚度和稳定性校核。2.介绍结构随机地震反应分析的常用方法,包括单点激励下平稳随机地震响应分析、单点激励下非平稳随机地震响应分析和多点激励下随机地震响应分析方法；详细说明几种常用地震动模型的适用范围,文章采用杜修力-陈厚群功率谱密度函数模型,并列表说明与震级、震中距和场地条件等诸多因素有关的模型参数的取值,为后续随机地震响应分析中的参数选择提供依据。3.为保证塔式起重机的后续动力学分析,采用模态分析方法获得塔机的振型特点和自振频率。采用反应谱法计算结构在不同荷载效应下的地震响应,并对不同方向地震激励时塔机的应力、位移结果进行分析比较。4.基于随机振动理论,对塔机进行随机地震激励下的动态响应分析。选用杜修力-陈厚群模型描述地震动输入,采用一致平稳随机地震响应分析方法,数值模拟塔机在五种不同组合方向输入地震激励时塔机内力、位移的随机地震响应。计算结果表明：Y向(竖向)地震波激励相比X向地震时塔机内力增幅明显,Z向地震波激励对塔身弯矩影响最大；Y向地震波是造成塔臂断裂的主要原因,Z向地震波过大易导致塔机倾覆。并将反应谱分析结果与随机振动法分析结果相比较。为塔式起重机的抗震设计与分析提供理论参考。
[Abstract]:With the rapid development of modern science and technology and architectural structure design, the construction height of tower crane is higher and higher. China is a multi-earthquake country, tower crane as a kind of towering equipment, its center of gravity is high, the mass distribution is uneven, and the flexibility is large. Once damaged by earthquake, it will not only cause huge loss of life and property, but also affect the course of earthquake relief and even produce secondary disaster. Therefore, the seismic response of tower crane can not be ignored. At present, the research on tower crane is mostly focused on modal analysis. The stability analysis and fatigue analysis, but the random seismic response analysis of tower crane is still in the exploratory stage, and has not formed a perfect seismic analysis theory and calculation method, so it has certain practical significance for the random seismic analysis of tower crane structure. The results can be used for reference in engineering practice. The main research work of this paper includes the following aspects: 1.Using the finite element analysis software ANSYS, the finite element model is established according to the actual engineering situation of tower crane, and the static analysis of tower crane structure is carried out. The stress distribution is obtained, and the strength, stiffness and stability of the tower crane are checked. 2. The common methods of random seismic response analysis of structures are introduced, including the stationary random seismic response analysis under single point excitation. Non-stationary random seismic response analysis under single point excitation and random seismic response analysis method under multi-point excitation, the application range of several commonly used ground motion models is explained in detail, and the power spectral density function model of du Xiuli-#china_person0# is used in this paper. The paratactic table shows the values of model parameters related to magnitude, epicentral distance and site conditions, and provides a basis for parameter selection in subsequent random seismic response analysis. 3. In order to ensure the subsequent dynamic analysis of tower cranes, The modal analysis method is used to obtain the modal characteristics and the natural vibration frequency of the tower crane. The response spectrum method is used to calculate the seismic response of the structure under different load effects, and the stress of the tower crane under different direction earthquake excitation is analyzed. Based on the random vibration theory, the dynamic response of tower crane under random earthquake excitation is analyzed. The du Xiuli-#china_person0# model is used to describe the ground motion input, and the uniformly stationary random seismic response analysis method is adopted. Numerical simulation of the tower crane internal force in five different combinations of directions input seismic excitation, Random seismic response of displacement. The calculated results show that the increase of internal force of tower crane is more obvious than that of X direction seismic wave excitation. The maximum effect of Z direction seismic wave excitation on the bending moment of tower body is caused by Y direction seismic wave, which results in the fracture of tower arm. The main reason is that the seismic waves in Z direction tend to overturn the tower crane, and the results of response spectrum analysis are compared with those of random vibration method, which provides a theoretical reference for the seismic design and analysis of tower cranes.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH213.3

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