【作者】 仇一颗；

【导师】 易伟建；

【作者基本信息】 湖南大学 ， 结构工程， 2001， 硕士

【摘要】 本文基于非线性有限元，直接采用材料本构关系形成单元M-N-ф本构矩阵的方法，推导混凝土杆系结构的单元刚度矩阵，其中考虑了材料非线性、几何非线性的影响，编制了相应的分析程序，并对单跨双层的钢筋混凝土框架和钢筋混凝土压弯构件进行了非线性全过程分析，计算值与试验结果吻合较好，从而为研究钢筋混凝土框架的非线性设计方法提供了理论分析手段。 本文在指出各国设计规范对钢筋混凝土框架柱计算长度取值方面存在的问题之后，分析了框架各柱单元控制截面二阶弯矩所用的计算长度的概念。随后用经过试验验证的非线性程序对二跨七层规则框架算例中各柱单元控制截面的二阶弯矩随各影响因素的变化规律进行了系列计算，在此基础上，以我国钢筋混凝土结构设计规范中标准柱偏心距增大系数的原型公式在本文程序条件下的修正公式为基点，取得所选算例中各柱单元的计算长度随各影响因素的变化规律，并得出了我国新规范的框架柱计算长度取值，在本文所计算的范围内是安全可靠的初步结论。更多还原

【Abstract】 The element stiffness matrixes of concrete frame and truss structures are derived in this paper based on the principle of nonlinear finite element. Utilizing the method tat M-N- (I) relations of element are formed directly from physical properties of material, the influence of material nonlinearity and geometric nonlinearity are taken into account in the element stiffness matrix. Besides, one two-story one-bay RC. Frames and several members with flexure and axial force have been analyzed by the matrix and corresponding program has been developed, too. The results calculated by using the approach in this paper are found to be in good agreement with the experimental results. So the program provides an efficient means of theoretic analysis in studying nonlinear design method for reinforced concrete frames.This paper points Out problems existing in the determination of the effective length of reinforced concrete frame columns adopted in current concrete structure design codes of various countries and analysis the implication of effective length which determines the second order moment in critical sections of the column members. A nonlinear analytical computer program, which has been verified by experiments, is used to analyze the varying laws of second order moment with respect to different influential factors in critical sections of columns in the example of one seven-story two-bay RC. frames. Based on the arnendatory formula of the magnification coefficient for the eccentricity of standard column (hinged end column with equal end eccentricities) specified in China concrete structure design code, (GBJ1O-89), appropriate formula and varying laws of the effective length of column manbers in the analyzed example frames with the influential factors have been obtained. Moreover, a rudimentary conclusion that the effective length of frame columns specified in the new code seems to be safe and reliable in varying degrees in the examples a~ialyzed has also been acquired in the paper.更多还原