针对承受跨中和末端集中荷载的悬臂梁侧向扭转屈曲,提出精确的稳定性计算准则。基于Bessel方程的闭合解法给出了二维稳定域。当中部的集中荷载向悬臂梁末端转移时,稳定域外凸的外限逐渐接近Dunkerley线。然而,当两个荷载的距离足够大时,Dunkerley线就不再适用。为快速预测屈曲荷载,还提出了一系列近似的计算公式。 Aiming at the lateral torsional buckling of cantilever beam subjected to concentrated loads at the mid-span and at the end, an accurate criterion of stability calculation is proposed. The closed solution based on the Bessel equation gives a two-dimensional stability domain. When the central concentrated load transferred to the cantilever tip, the outer limit of the convexity of the stable region gradually approached the Dunkerley line. However, the Dunkerley line no longer applies when the distance between two loads is large enough. In order to predict the buckling load rapidly, a series of approximate formulas are also proposed.