【摘要】 针对材料力学中关于中性轴位置的讨论，开展轴压下中性轴位置对梁屈曲载荷的影响研究。利用轴向静力平衡方程及弯曲方程，分别推导出圆形截面梁和矩形截面梁中性轴与形心轴偏移量的表达式，并得到了轴压作用下梁的屈曲载荷公式。算例分析表明，轴压作用下梁的中性轴与形心轴不再重合，中性轴发生偏移，并随着梁跨高比的减小而有一定程度的增大，但梁中性轴偏移量非常小，对梁惯性矩的影响不大，对梁的屈曲载荷未造成显著影响，可以忽略不计。更多还原

【Abstract】 According to the discussion of neutral axis position in mechanics of materials, the influence of neutral axis position on the buckling load of the beam under axial compression is studied. Using the axial static equilibrium equation and the bending equation, the expressions of the offset of neutral axis and centroid axis of the beam with circular section and rectangular section are derived respectively, and the buckling load formula of the beam under axial compression is obtained. The numerical example analysis shows that the neutral axis of the beam no longer coincides with the centroid axis under axial compression, and the neutral axis shifts, and increased with the decrease of the span to height ratio of the beam. However, the offset of the neutral axis of the beam is very small, so the influence on the moment of inertia of the beam is so small that the buckling load of the beam is not significantly affected and could be ignored.更多还原