整体壁板结构弹塑性弯曲中性层位置分析

中性层位置是壁板结构设计和分析及其弯曲成型工艺的重要参数,工程上将截面形心作为弹塑性弯曲中性层位置的方法存在很大误差。通过弹塑性分析,考虑了材料塑性强化效应,建立了一种便捷的计算整体壁板结构弹塑性弯曲中性层位置的方法,并和数值仿真结果进行了对比,分析结果表明:弹性弯曲时,中性层位于截面形心;而进入塑性弯曲阶段,中性层位置随着弯曲半径的减小向蒙皮方向显著移动;在整体壁板常用的相对弯曲半径下(ρ/t≥10),壁板的变薄可以忽略不计,应力中性层和应变中性层几乎重合。

Analysis of Neutral Surface Position of Integrally StiffenedPanel in Elastoplastic Bending

The position of neutral surface of integrally stiffened panel is important for parameter design and structural analysis,together with bending process.In engineering,the centriod is treated as the position of integrally stiffened panel in elastoplastic bending,and there is large error for this method.In this work,a new method for the calculation of neutral surface position is set up,considering the strain-hardening of a material,and the result is compared with that of numerical simulation.Result shows: the neutral surface of integrally stiffened panel in elastic bending lies in the centriod,and it moves to skin side as bending radius getting smaller in plastic bending;when the relative bending radius is small(ρ/t≥10),thinning of panel is ignorable,and neutral surface of stress and strain lie at almost the same position.