黏弹性复合材料结构阻尼性能的分析及优化设计

Analysis and Optimization Design about Damping Performance of the Viscoelastic Composite Structures

黏弹性阻尼层复合材料结构具备强度高及减震降噪特点。本研究以一阶剪切变形理论描述结构位移场,利用汉密尔顿原理推导出控制方程;以四边简支的黏弹性复合材料结构为例,满足其边界条件的振型解用Navier双三角函数表示;得到了结构的动态响应、固有频率和损耗因子;应用改进的遗传算法对黏弹性复合材料结构的损耗因子进行优化。优化结果表明,通过对纤维铺设角θ、黏弹性阻尼层与复合材料层厚度比λ和黏弹性阻尼层与复合材料层剪切模量比G_2的优化设计,明显增大了黏弹性复合材料结构的损耗因子,从而提高了其阻尼性能,达到了减震降噪的目的。

The composite structures with a viscoelastic mid-layer damping materials have the characteristics of higher strength,weaker vibration and lower noise. The first-order shear deformation theory is used to describe the deformation of the structures. The governing equations are deduced by the Hamilton principle. The double Fourier series which satisfy the boundary conditions are acquired to express the vibration mode solution for the four simply supported composite structures. The results of the dynamic response of structures,the natural frequencies and loss factors are obtained. Improved genetic algorithm is used for the optimal design of the loss factor of viscoelastic composite structures. Numerical results show that the loss factor of the viscoelastic composite structures is significantly increased by the optimal design of fiber angle θ,damping layer thickness and the layer thickness ratio λ,and modulus ratios G_2. The damping properties of the structures are thus improved and the goals are realized to reduce vibration and weaken its noise.