【摘要】 本文论述了变截面梁单元平面内稳定分析方法，比较了不同类型梁单元（等截面梁单元、普通位移模式变截面梁单元、积分位移模式变截面梁单元）对变截面刚架平面内稳定分析的差异。利用上述有限元法，给出了对称刚架变截面柱计算长度系数的实用计算公式，并分析了横梁轴力对刚架柱稳定的影响。更多还原

【Abstract】 This paper presents an in-iiane instability analysis of a steel portal frame with tapered members, and the finite element convergence behavior of the three types of finite elements adopted is studied in the analysis. Quite a number of numerical studies are cwhed out to investigate the variation of the effective-length factors of the tapered columns forming the frame- By use of the finite element method, a practical formula for computing the effective-length factors of tapered columns is put forward, which can be considered to be satisfactory in comparison with the results obtained from the finite element method. The influence of axial force in beam on the stability of portal frame is involved in the study.更多还原