夹层FGM圆柱壳在扭转载荷作用下的弹性稳定性

采用半解析方法研究了两端简支的功能梯度夹层圆柱壳在端部扭转载荷作用下的弹性稳定性.考虑圆柱壳的里外表层为均匀材料,中间层为材料性质沿厚度方向连续变化的功能梯度材料,并且在界面处的材料性质保持连续. 基于Flügge薄壳理论,建立了位移形式的结构静态屈曲控制方程.根据边界条件将位移表示为三角级数形式,获得包含柱壳端部扭转载荷参数的近似线性代数特征值问题,并通过数值方法求得了表征结构失稳特征的临界载荷. 数值结果表明,临界载荷随着半径与厚度比的增加而减小,随着功能梯度中间层的弹性模量的平均值的增加而增加. 

ELASTIC STABILITY OF CIRCULAR CYLINDRICAL SHELLS WITH FGMS LAYERS UNDER END TORSION FORCE

By using semi-analytical method, elastic stability of a simply supported FGM sandwich circular cylindrical shell under torsion loading was studied. The inner and outer layers of the shell are comprised of the same homogeneous and isotropic material, and the middle layer is made of an isotropic functionally graded material whose properties varies continuously in the thickness direction from the inner layer to the outer layer, and keeps continuation in the material properties of the interface. Firstly, based on the Flügge thin shell theory, the governing equations for static buckling of the structure in terms of displacements were formulated. Secondly, by introducing the displacements in terms of trigonometric functions that identically satisfy the boundary conditions, an eigenvalue problem for linear algebraic equations including the torsion force parameter is obtained. Finally, critical buckling load characterizing the features of instability of the structure were obtained by numerical method. The numerical results show that the buckling load decreases with an increases in the radius to thickness ratio, and increases with an increase in the average value of Young's modulus of the FGM middle layer.