基于几何因子的复合材料层合板颤振特性
Flutter characteristic of composite laminates with lamination parameters
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摘要: 首先实现了基于几何因子的复合材料层合板建模方法, 解决了几何因子与Natran的参数输入问题, 并通过一个简单算例进行验证.其次, 在基于几何因子的层合板建模方法的基础上, 采用p-k法计算颤振速度和发散速度, 进行基于几何因子的悬臂复合材料层合板颤振和发散特性分析研究, 重点研究了主轴刚度和弯扭耦合效应对颤振速度的影响.分析结果表明: 相对于弯曲刚度, 扭转刚度的改变对颤振速度的影响更显著, 且扭转刚度越小, 颤振速度越低;颤振模式随着刚度特性的改变有可能发生转变, 导致颤振速度的突然变化和几何因子空间内颤振速度等高线的不连续; 在正则化刚度矩阵不变的情况下, 层合板厚度增加会同时提高颤振速度和发散速度, 且颤振速度与发散速度与厚度大致呈线性关系.Abstract: Composite laminate modeling based on lamination parameters is fulfilled and the parameter input problem of lamination parameters with Natran is solved, using a simple numerical example to demonstrate its validity. With composite laminate modeling method based on lamination parameters and p-k method for calculation of flutter and divergence speeds, flutter and divergence characteristics of a cantilevered laminate are studied using lamination parameters. The effects of principal-axis stiffness and bending-torsional coupling on the flutter speed are emphasized The results show that compared with the bending stiffness, change of torsional stiffness has a more obvious influence on flutter speed. And the flutter speed decreases with decrease of torsional stiffness. The switch of flutter mode may occur due to change of stiffness, which leads to interrupt change of flutter speed and discontinuity of flutter speed contours in lamination parameter plane. With constant normalized stiffness matrix, the flutter and divergence speeds can be improved and have a linearity relationship with the laminate thickness.