【作者】 缪林卫；

【导师】 李晓文；

【作者基本信息】 西安建筑科技大学 ， 防灾减灾工程及防护工程， 2011， 硕士

【摘要】 钢筋混凝土烟囱是工业生产中重要的工程项目,属于典型高耸结构体系,对水平侧移产生的P-△效应反应比较敏感。由于现代工业发展的需要,烟囱高度也向越来越高的方向发展,更加大了P-△效应的影响。虽然国内学者研究结构的二阶效应已取得了很大的成就,但是现阶段钢筋混凝土烟囱结构的软件设计过程中,对于烟囱二阶效应的分析还有待澄清,需做进一步的研究。本文分析总结了钢筋混凝土结构二阶效应的分析方法,着重对高耸结构P-△效应的分析方法进行了研究。在考虑钢筋混凝土烟囱受P-△效应的影响时,采用能量法推导出适用于烟囱设计的计算公式,对烟囱结构的内力与变形进行具体的计算。运用卡氏第一定理与最小势能原理,得出烟囱在风荷载作用下的结构顶点位移、底部附加弯矩和弯矩放大系数。同时按照烟囱设计规范计算风荷载作用下底部附加弯矩和顶点位移,比较两种方法计算结果之间的差别。通过比较,得出考虑烟囱结构刚度折减系数的合理值。比较折减之后的能量法与烟囱设计规范两种计算结果之间的差别。研究静力弹塑性分析方法,采用Sap2000对烟囱进行静力弹塑性分析,得出结构荷载-位移曲线与结构的整体变形曲线。将该分析曲线与能量法所选用的形函数曲线进行比对,看是否一致。对240m烟囱进行Sap2000有限元分析,得出在不同刚度折减系数下,结构的顶点位移和内力分布情况。通过比较不同刚度折减系数下的顶点位移值与应力分布情况,选择与烟囱设计规范和能量法结果相一致的刚度折减系数。更多还原

【Abstract】 The reinforced concrete chimney is an important project in industrial buildings, which is a typical high-rise structure, and it is sensitive to P-Δeffect caused by horizontal displacement. With the development of modern industry, the chimney is more and more high which make us pay more attention on the P-Δeffect of chimney. In despite of the research about second-order effect of structure has made great achievements, but the analysis about second-order effect of chimney remains to be clarified in the process of chimney design, and need to do further research.This paper which analyze and summary the measures of second-order effect of reinforced concrete structure, and focus more attention on the analysis of P-Δeffect of high-rise structure. Considering the impact of P-Δeffect, derive the reasonable chimney design formula on the basis of energy method, and go into the specific calculation of inter forces and deformation. By using the Castigliano’s first theorem and minimum potential energy principle, the apical displacement and additional bending moment at the bottom and moment magnification coefficient of chimney can be obtained when the chimney under the action of wind load. Figure out the bottom additional bending moment under wind load based on criterion of chimney design, and compare the difference of results which derive from the two approaches. By comparison, the reasonable value of chimney stiffness reduction coefficient can be achieved. Compare the two results derived from criterion of chimney design and energy method when consider stiffness reduction into account.Based on nonlinear static analysis method, carrying on chimney pushover analysis by SAP2000, and obtain the load-displacement curve and the Integral deformation curve of chimney. Compare curves derived from analysis with curve of shape function of energy method, and by compare to see if they consistent or not.Doing the finite element analysis of chimney with the height of 240m by SAP2000, the apical displacement and situation of internal force distribution under different stiffness reduction coefficient can be gained. By compare the apical displacement value and stress distribution under different stiffness reduction coefficient, selecting a reasonable stiffness reduction coefficient and making the achieved result consistent to result derived from standard of chimney design and energy method.更多还原