敷设支撑层的约束阻尼梁减振优化设计

Reducing vibration and optimization design of beam with a stand-off constrained layer damping patch

约束阻尼是板梁减振降噪的重要手段之一,敷设支撑层的约束阻尼结构能够获得更好的减振效果。基于有限元方法建立简支约束阻尼梁模型,以阻尼段段数、长度、段间间隙、支撑层厚度作为设计变量,梁结构的前4阶模态损耗因子乘以权值的和为目标函数,应用序列二次规划法对整个结构进行优化。在不同质量的约束条件下,分析比较了选取不同权值时约束层连续与间断情况下梁中点的振幅变化和损耗因子的变化。实例结果表明:优化设计能够保证在引入质量较小的情况下,达到更好的减振效果。

Constrained layer damping is an important means of reducing vibration and noise for plates and beams,a better damping effect can be achieved from the partial stand-off constrained layer damping.Based on finite element method,the model of simply-supported beams covered with constrained layer damping patches is established.The number,length and space between of damping patches and the thickness of stand-off layer are taken as the design variables,the sum of first four modals＇ loss factor multiplied by the weight is considered as the objective function,the structure is optimized by sequential quadratic programming method.Under the conditions of different masses,the amplitude of mid-point and the loss factor of the structure are analyzed and compared when different weights are taken under the condition that the constrained layer is discontinuous and continuous.Results of examples show that the optimal design can guarantee better damping effect under the condition that the introduced mass is much smaller.