不同自由端约束条件下双轴对称工字形截面悬臂梁的稳定性

STABILITY OF DOUBLY SYMMETRIC I-SECTIONAL CANTILEVERS WITH DIFFERENT BOUNDARY CONDITIONS AT TIP

对自由端侧向位移和扭转简支约束、自由端仅扭转约束和自由端仅简支扭转弹性约束条件下,双轴对称工字形截面悬臂梁的稳定性进行研究,并提出临界弯矩的计算公式。这一计算公式能够考虑悬臂梁长细比的变化,以及横向荷载作用点沿截面高度方向变化对其临界弯矩的影响。通过与有限元结果的比较可以发现,所提出的计算公式可以获得精度良好的临界弯矩值。

The lateral buckling of cantilevers of doubly symmetric I-section with different boundary conditions at tip was investigated in this paper, where three boundary conditions at tip in terms of practical use, both the lateral translation and torsion displacements clamped, torsion displacement clamped and torsion displacement elastically restrained, were mainly concerned. The solutions for the buckling load of these cantilevers under two typical load cases, the uniformly distributed loads and one concentrated load at tip, were proposed, in which the effects of the beam length and loading position in the vertical direction along the cross-section on the buckling load could be considered. Comparisons of lateral buckling loads from the presented solutions and the finite element analyses showed very good agreements between each other, which indicated the good accuracy of the proposed solutions.