Abstract

The optimal stacking sequence design for the maximum frequencies of the lowest three modes of symmetric variable stiffness composite laminated beams in air and in water is investigated for the first time using a layer-wise optimization method. Two fiber orientation angles in each layer are considered as design variables. The shifted path technique is used to construct the fiber paths. The p-version of the finite element method is used in conjunction with the Euler–Bernoulli beam theory coupled with torsion to calculate the frequencies. The numerical results are validated by comparison with published results for a single-layer constant stiffness composite beam with rectilinear fibers in air and in water. Extensive results are presented, which may serve as a benchmark for future research. Furthermore, a parametric study is performed showing the effects of geometrical and mechanical parameters and boundary conditions on the optimal solutions.

摘要

首次采用分层优化方法研究了对称变刚度复合叠层梁在空气和水中最低三种模态的最大频率的最优堆叠序列设计。每层中的两个纤维取向角被视为设计变量。移动路径技术用于构建光纤路径。p _- 有限元方法的版本与欧拉-伯努利梁理论结合使用扭转来计算频率。通过与在空气和水中具有直线纤维的单层恒定刚度复合梁的公布结果进行比较，验证了数值结果。提出了广泛的结果，可以作为未来研究的基准。此外，还进行了参数研究，显示了几何和机械参数以及边界条件对最优解的影响。