双材料层合梁的弯曲切应力分析

Analysis of shearing stress in bending of bi-material laminated beam

为分析由不同材料组成的任意多层层合梁的弯曲性能,以一矩形截面层合梁为例,采用相当截面法确定了组合截面中性轴的位置,利用静力平衡条件建立任意多层复合材料层合梁横截面上任一点处弯曲切应力的一般公式。在此基础上,进一步推导了双材料层合梁的弯曲切应力计算表达式,表明弯曲切应力在不同材料层沿截面高度分别按二次抛物线变化,并且在结合面处保持连续。通过对双材料层合梁截面优化设计问题的分析,为避免弯曲切应力引起层合梁结合面处的脱层问题提供了设计理论依据。

In order to analyze the bending properties of the composite laminated beam consisting of arbitrary number of layers,one rectangle laminated beam model is presented as the calculated example and the equivalent cross-section method is adopted to localize the position of the neutral axis.Based on the static equilibrium condition,the general formula of shear stress in bending of composite laminated beams is established.On this basis,the calculation expression of shear stress in bending of bi-material laminated beam is deduced.Results show that the shear stress varies along the section height in a quadratic parabola and keeps continuous at the bonding surface.Finally,a theoretical basis is proposed for the optimization design of bi-material laminated beam to avoid the delamination at the joint of the laminated beam caused by the bending shear stress.