This work deals with the modeling of laminated composite and sandwich shells through a variable separation approach based on a Reissner’s Variational Mixed Theorem (RMVT). Both the displacement and transverse stress fields are approximated as a sum of products of separated functions of the in-plane coordinates and the transverse coordinate. This approach yields to a non-linear problem that is solved by an iterative process, in which 2D and 1D problems are separately considered at each iteration. In the thickness direction, a fourth-order expansion in each layer is used. For the in-plane description, classical Finite Element method is used. Numerical examples involving several representative shell configurations (deep/shallow, thick/thin) are addressed to show the accuracy of the present method. It is shown that it can provide quasi-3D results less costly than classical LW computations. In particular, the estimation of the transverse stresses, which are of major importance for damage analysis, is very good.

中文翻译：

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基于Reissner混合变分定理的可变分离方法圆柱复合壳结构建模

这项工作通过基于Reissner的变分混合定理（RMVT）的可变分离方法来处理层压复合材料和夹层壳的建模。位移和横向应力场都近似为平面内坐标和横向坐标的分离函数的乘积之和。这种方法产生了一个非线性问题，该问题通过迭代过程得以解决，其中在每次迭代中分别考虑2D和1D问题。在厚度方向上，在每个层中使用四阶扩展。对于平面内描述，使用经典的有限元方法。数值示例涉及几种代表性的壳体配置（深/浅，厚/薄），以显示本方法的准确性。结果表明，与传统的LW计算相比，它可以提供更便宜的准3D结果。特别地，对于损伤分析而言，最重要的是横向应力的估计是非常好的。