薄壳结构噪声约束下附加阻尼层的最小成本设计

Minimum cost design of shell structure with additional damping under noise constraint

薄壳附加阻尼层旨在降低薄壳结构的噪声,为此本文研究该系统成本最小的优化设计:以包含阻尼的结构各层的倒厚度为设计变量,以满足设计的噪声要求为约束条件,以结构成本(包括约束阻尼层结构的薄壳基础层、阻尼层、约束层的材料费用)作为目标函数。利用K-S函数得到最大振动加速度级来描述噪声,运用响应面方法显式化噪声约束函数,采用序列二次规划求解优化模型。算例表明,增加阻尼层和约束层的厚度有利于增强结构的阻尼和刚度,优化设计使得薄壳结构的造价降低8.44%,且使结构的振动综合指标降低了27.08%,从而使结构减振降噪性能得到了提高。

The constrained damping is used to paste on the shell structure for the vibration and noise reduction.Therefore,this paper researches on the optimal design of minimizing the cost of the system: taking the reciprocal values of the thickness of each layer of the structure with damping as design variables,taking satisfying the noise requirement as the constraints,and taking the cost(including the material cost of the based layer,the material cost of the damping layer,and the material cost of the constrained layer) as the objective function.The K-S function is adopted to get the maximal vibration acceleration level for expressing the noise.The response surface methodology is used to explicit the noise constraints function.The sequential quadratic programming is employed to solve the optimization model.The example shows that,the increment of the thickness of damping layer and constrained layer is beneficial to strengthening the structural damping and stiffness.By using optimal design,the cost of the structure is reduced by 8.44%,the synthesis parameter of the structural vibration is reduced by 27.08%,and the property of the vibration and noise reduction sees a great improvement.