摘要:
采用有限元数值模拟方法, 研究了蒙皮内含分层损伤复合材料格栅加筋板结构(AGS) 的稳定性问题。对蒙皮和肋骨分别采用基于Mindlin 一阶剪切理论的复合材料层合板单元和层合梁单元来模拟, 推导了相应的有限元列式, 并通过坐标变换, 利用蒙皮与肋骨的几何连续条件, 形成了AGS 的单元刚度阵和几何刚度阵, 建立了含损伤AGS 稳定性分析的有限元控制方程。通过典型算例, 研究了压缩载荷作用下, 分层形状、分层大小、分层深度、肋骨的高度和宽度、布置方式等因素对AGS 的稳定性特征的影响。数值结果表明, 含分层损伤的AGS 具有十分复杂的屈曲性态。屈曲临界力和屈曲模式与分层面积、分层形状、分层深度、肋骨的高度和宽度、布置方式和位置均密切相关。
Abstract:
A finite element method was developed for the numerical analysis of advanced grid stiffened st ructure(AGS) , and the stability problem of AGS with an embedded delamination was investigated. Based on the Mindlinfirst-order shear deformation theory , a composite laminates element and a beam element were adopted to model theskin and the stiffener , respectively. The corresponding formulae for finite element analysis were deduced. By coordinate t ransformation and the geomet ry continuum condition of the skin and the stiffener , the element stiffness mat rices and geomet rical stiffness mat rices for the AGS were deduced. The governing equation for the stability problem ofthe composite grid stiffened plate and shell was established. The effect s of configuration , size , and location of thedelamination , and the height , the width , the dist ribution of the stiffeners on the stability characteristics of the AGSsubjected to a compressive load are discussed. The numerical investigation indicates that the buckling behavior of theAGS is much more complicated. The buckling load and modes relate to the configuration , size , and location of thedelamination , and the height , the width , the dist ribution of the stiffeners closely.
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