考虑剪切变形影响的框架结构稳定性

Stability of Frames: Effects of Shear Deformation

巨型框架结构由于框架梁柱截面的剪切变形较大,在分析巨型结构整体稳定性时,应当同时考虑巨型梁柱的弯曲变形与剪切变形。本文研究了框架梁和框架柱截面的剪切变形对框架结构整体稳定性的影响。分别研究了简单对称框架柱顶作用有相同集中荷载时、简单对称框架柱顶作用有不等集中荷载时、以及不对称框架柱顶作用不等集中荷载时,框架结构的整体稳定性。分析了不对称框架柱剪切变形对框架稳定性的影响及框架发生整体有侧移失稳的内在规律。着重讨论了框架梁截面的剪切变形对框架整体稳定性的影响规律,根据这一规律提出了简化方法以考虑横梁剪切变形的影响。本文提出了计算框架临界荷载的近似计算方法,与有限元法的结果对比,具有很好的精度,近似算法均考虑了框架梁和框架柱截面的剪切变形及弯曲变形。

For mega-scale frame structures, the shear deformations of mega beams and columns are significant, and thus necessary to be considered in the stability analysis of the structure systems. The stability of rigid frame structures is analyzed by considering the effects of beam and column shear deformations. The stability of symmetric frames with symmetric or asymmetric loads on the top of columns and the stability of asymmetric frames with asymmetric loads on the top of columns are studied, respectively. The effects of column shear deformations are identified and the characteristics of frame sway buckling are determined. The effects of beam shear deformations are discussed, and a simplified approach is proposed to take account of such effects. Approximate solutions for critical loads of the frame are proposed, and comparing with the FEM solution proves good accuracy.