矩形截面钢梁在纯弯曲作用下的变形探讨

Discussion on Deformation of Rectangular Section Steel Beam Under the Action of Pure Bending

为了探讨矩形截面钢梁在纯弯曲作用下其横截面上的应力分布,在传统的弯曲试验基础上,采用电测应力分析的方法对梁横截面上的应力分布进行测试。研究表明:矩形截面钢梁在纯弯曲作用下其横截面呈梯形状态,这是因为在凹向变形状态下,中性层上方纵向纤维受压应力,其中性层上方随远离中性层的高度h的纵向层面缩短而横向变宽,而中性层下方随远离中性层的高度h的纵向层面伸长而横向变短,原先的几何中性层也由物理中性层取代。

To study the cross-section stress distribution of the rectangular section steel beam under the action of pure bending based on the bending test,the cross-section stress distribution is tested by the electronic test method.The research indicates that the cross section of the rectangular section steel beam under the action of pure bending appears to be trapezoidal,this is because under the concave strained condition,the longitudinal fibers above the neutral surface suffer pressure stress,the longitudinal sections of the above fibers are shortened while the latitudinal ones widens,as the height-h of the above fiber from the neutral one develops,however,for the below fibers it＇s longitudinal sections are extended while the latitudinal ones are shortened,and therefore the original geometry of neutral section is replaced by the physical one.