【作者】 曹云中；

【导师】 唐锦春； 干钢；

【作者基本信息】 浙江大学 ， 结构工程， 2005， 博士

【摘要】 随着生活水平步入小康,人们要求提高空间利用率以获得尽量多的使用空间。把柱的截面设计成“L”,“T”及“+”字形,使填充墙与柱壁同厚,柱处不出现凸出的棱角,室内空间有效利用率可大大提高。由于异形柱框架结构的优越性,国内外在异形柱及异形柱平面框架方面已有不少研究,但异形柱空间框架性能的研究尚处于初步探索阶段。为了能在实际工程中更好地运用这类结构,本文提出一种空间异形柱框架结构的非线性有限元分析方法,并结合单向及反复推覆分析方法对空间异形柱框架结构抗震性能进行分析,然后在推覆分析的基础上做一定的动力时程计算,另外还做了一些试验研究。 本文具体的内容有: 1.空间异形柱框架结构非线性有限元分析理论 首先假设框架梁与柱符合平截面假定、钢筋与混凝土之间的粘结可靠、忽略裂缝中骨料之间的咬合力、钢筋无横向抗剪作用、忽略横向剪切变形及扭转变形。然后确定反复加卸载时钢筋与混凝土的应力—应变本构关系。针对该框架特点,对框架作适当的单元划分,并将异形截面划分为几个规则的矩形区域,然后运用组合层合单元、分区离散截面法及主从系统中的偏心转化法对异形截面的矩形区域进行分离与组合,并用子结构法及静力凝聚法提高计算效率。混凝土与钢筋采用差量叠加式模型。根据非线性有限元原理,结合增量物理方程和增量几何方程,提出简化非线性计算模型,探讨能较正确、全面描述空间异形柱框架结构工作时的抗震性能的方法。 2.空间异形柱框架结构静力弹塑性分析程序 在对异形柱框架抗震性能研究中运用静力推覆分析。在推覆分析过程中用逐步加减位移的自修正法来控制卸载及再加载,使负刚度阶段的计算得以实现。以顶层上的水平荷载为基准,其它各层上的水平荷载按倒三角的比例关系施加。当空间框架受到的水平力与某水平坐标轴有一小于等于45°夹角时,以顶层位移量在该轴方向的分量作为控制量并得到此时该轴方向的水平力分量,然后由该轴方向的水平力分量结合保证水平力方向角不变的条件得到另一水平坐标轴方向上的水平力分量。为避免材料本构关系的转折带来计算波折,并且为便于判断加卸载,在各级荷载的各自修正循环步中进行多次材料状态分析与取值,取值过程用割线模量搜索。在空间异形柱框架非线性有限元基础上编制推覆分析程序,并对程序的有效性进行了验证。更多还原

【Abstract】 It is advocated using space fully and freely following the development of living condition. Bulgy edges of column disappear while the column sections being designed to be shapes of "L" , "T" and "+" . Then the service efficiency of indoor space can be improved greatly. Study on structure with special-section column has begun on the world because of its superiority, but study on performance of 3d-frame with special-section column is still at initial stage. In order to put this kind of structure into practice properly, in this paper, analyzed the aseismic performance of the frame with PUSH-OVER method under the unilateral and the reversed cyclic loading and Dynamic and time-historical analysis method after studying nonlinear finite analysis theory on 3d-frame with special-section column, then supplied some test.The main contents in this paper:1. Nonlinear finite analysis theory of 3D-frame with special-section columnNonlinear finite analysis theory of 3D-frame with special-section column was proposed based on some necessary hypothesis and strain-stress constitutive equations of materials. According to the frame features such as irregular cross-section of the column, divided the frame into elements properly to obtain a simple calculation model. In this model, zonal discrete section method, eccentricity transition matrix in master-slave system were applied. Substructure, and static condensation were utilized in this model to increase computational efficiency. Utilized the differential superposition method to combine concrete with bar. Then the nonlinear finite analysis theory of 3D-frame with special-section column was presented.2. Static elasto-plastic analysis program of 3D-frame with special-section columnDuring analyzing the aseismic performance of 3D-frame with special-section column, PUSHOVER method was used. And self-modifying step-iterative method under condition of incremental displacement was applied to continue the calculation on descending branch. The PUSHOVER calculation program for analyzing the aseismic performance of 3D-frame with special-section column, which was based on nonlinear finite analysis theory of 3D-frame with special-section column, was set up andverified.3. Study on aseismic performance of 3D-frame with special-section column compared with 3D-frame with rectangular-section columnAfter studied on the aseismic performance of the 3D-frame with special-section column and 3D-frame with rectangular-section column, obtained common performance and specific performance of the two kinds of structure such as failure process, bearing capacity, lateral displacement, ductility, torsion, hysteretic performance, stiffness degeneracy and endogen force feature. The result of comparison on aseismic performance can be available to structure lectotype during design.4. Load influence on aseismic performance of 3D-frame with special-section columnAfter analyzed the 3d-frames with special-section column by PUSHOVER method under horizontal loading with various direction, under vertical loading with various arrangement and under various axial compression ratio, obtained aseismic performance such as failure process, bearing capacity, lateral displacement, ductility, torsion, hysteretic performance, stiffness degeneracy and endogen force feature. The result on aseismic performance of these frames under various loads can be available to loading treat during design.5. Influence of structure parameter on aseismic performance of 3D-frame with special-section columnAfter analyzed the 3d-frames with special-section column by PUSHOVER method with various length-width ratio of limb, with various distribution of bar on column section and with various ratio of reinforcement in column and beam, obtained aseismic performance such as failure process, bearing capacity, lateral displacement, ductility, torsion, hysteretic performance, stiffness degeneracy and endogen force feature. The result on aseismic performance of these frames with various structure parameters can be available to control structure parameter during design.6. Dynamic and time-historical analysis of 3D-frame with special-section columnGained dynamic performance of 3D-frame with special-section column after dynamic and time-historical analysis on the 3d-frames with special-section column under EL-centro seismic wave with 8 degree and 9 degree of seismic fortification intensity was carried on.7. Test of 3D-frame with special-section columnStudied service behavior and failure process of the 3D-frame with special-section column under the reversed cyclic loading with low frequency and explored aseismic performance of the 3D-frame with special-section column at elasto-plastic stage bypseudo-static test of single span and single story 3D-frame with special-section column under different direction horizontal load.Obtained aseismic performance of the 3D-frame with special-section column such as bearing capacity, lateral displacement, ductility, torsion, hysteretic performance, stiffness degeneracy and endogen force feature and gained service behavior and failure process of the 3D-frame with special-section column by study on aseismic performance of 3D-frame with special-section column. And gived out some suggestions for design of 3D-frame with special-section column.更多还原