工字形组合截面梁腹板的局部屈曲

为正确预测工字形组合截面梁的承载力,针对其腹板的局部屈曲问题进行了数值分析和试验.有限元分析表明梁腹板会在集中荷载下方发生局部屈曲或对无加劲肋的梁会在支座处发生局部屈曲.同时表明,正应力与剪应力基本呈线性关系,腹板上边缘处的局部压应力并不显著影响腹板的屈曲.采用硅橡胶制作模型梁,进行腹板屈曲试验,证明了数值分析结果的正确性.经对计算结果回归分析,给出了腹板屈曲计算公式的一种新形式.

Local web buckling of thin-wailed I-beams

In order to predict the load capacity of thin-walled steel I-beams,the local web buckling was investigated both numerically and experimentally. Finite element analysis of the beams shows that the web buckles locally either under the concentrated load or at the support if the beam is unstiffened. A linear relationship between the normal stress and the shear stress was revealed by the finite element modeling. The local compressive stress at the top of web does not affect the buckling of web significantly. The numerical findings were further validated by testing of small I-beams made of silicone rubber. A new form of design equation for local web buckling was given by statistics and regression of the analytical results of beams.