摘要
根据Timoshenko二广义位移梁理论,导出了考虑剪切变形影响的压弯构件的解析解和弯矩-转角位移方程。利用位移法分析了单层单跨框架、多层多跨框架的无侧移、有侧移失稳问题,建立了框架失稳时关于计算长度系数的超越方程。计算了框架柱不同剪弯刚度比时考虑剪切变形与不考虑剪切变形影响的临界荷载比。结果显示,剪切变形显著影响无侧移失稳框架的计算长度系数,但不影响有侧移失稳框架的计算长度系数;剪弯刚度比越大,剪切变形影响越小,当剪弯刚度比>30时剪切变形影响不超过5%;考虑剪切变形影响的临界荷载比相应不考虑剪切变形影响的临界荷载小,现行'规范'采用不考虑剪切变形影响的计算长度系数法偏不安全。
Based on Timoshenko theory of deep beam, analytical solution and moment-slope function were presented. Using the displacement method, buckling stabilities of single-story, single-bay and multi-story, multi-bay flames were analyzed, and transcend equations about effective length factors were derived. The critical load ratios corresponding to different shear-flexural ratios were computed. Results show that shear deformation affects the effective length factor of non-sway flames much more significant than that of sway frames. The larger the shear-flexural ratio, the less the shear deformation effects. When the shear-flexural ratio is greater than 30, the influence of shear deformation is less than 5%. Shear deformation effect makes the critical load lower than code expected. Current code without considering the shear deformation effect is not safe.
出处
《工程力学》
EI
CSCD
北大核心
2009年第3期99-105,共7页
Engineering Mechanics
基金
国家自然科学基金项目(50478032)
长沙理工大学奖励基金项目(1004171)
关键词
结构工程
计算长度系数:剪切变形
稳定分析
超越方程
structural engineering
effective length factor
shear deformation
stability analysis
transcendequation
