上下翼缘同时受荷的工字形钢梁整体稳定性分析

现行钢结构规范中没有工字形钢梁在上翼缘均布荷载、下翼缘跨中集中荷载作用下整体稳定的计算方法.采用能量法推导出这两类荷载作用下双轴对称工字形钢梁的临界承载能力计算公式,总结了荷载比例系数对临界弯矩的影响规律.并采用有限元方法对该理论公式进行验证,在荷载比例小于3时,计算结果与理论公式吻合较好.在此基础上,通过计算分析提出了这类荷载作用下工字形钢梁的等效临界弯矩系数的计算公式,该公式具有较好的计算精度.

Overall Stability of the I-beams under Loading Both on Upper and Lower Flanges

The calculation methods of the overall stability of I-section steel beams, under loading both on upper and lower flanges, are not contained in current steel structure code. Energy method was used to derive the critical moment formula of biaxial symmetry I-beams under the loading mentioned above, and the effects of the load scale factor on the critical moment were also summarized. The finite element method was used to verify the moment formula. The results of the finite-element calculation were consistent with the theoretical results when the load scale factor was less than 3. In addition, through computational analysis, the formula of the equivalent critical bending moment coefficient for the I-section steel beams under the same loading was put forward. This formula has a preferable calculation accuracy.