聚氨酯泡沫层对隔离复合阻尼材料减振性能影响

The Influence of Polyurethane Foam Layer on the Damping Performance of Stand-off Composite Damping Materials

以不同密度的硬质聚氨酯泡沫塑料作为隔离层,以D 803 Z型丁腈橡胶为阻尼层,制成一系列用于控制结构振动的聚氨酯 橡胶隔离复合阻尼材料。采用动态热机械分析法(DMA)分析了聚氨酯硬泡和橡胶材料的动态力学性能,并通过锤击实验从幅频曲线、复合损耗因子、模态频率等方面将敷设隔离复合阻尼材料的悬臂梁与橡胶自由阻尼悬臂梁进行了对比分析,探讨了4种不同密度的聚氨酯泡沫对隔离复合阻尼悬臂梁减振性能的影响。结果表明:聚氨酯泡沫损耗因子相对较小,其主要作用是扩大阻尼层的形变;相比于自由阻尼悬臂梁,隔离复合阻尼悬臂梁的前三阶模态振动响应降低了8%~52%,复合损耗因子提高了2~3倍;随着聚氨酯泡沫密度的增大,各阶模态的振动响应持续降低。聚氨酯 橡胶隔离复合阻尼材料能够有效降低结构的振动,适当提高聚氨酯泡沫层的密度有助于进一步改善材料的减振性能。

A series of polyurethane rubber stand off composite damping materials were prepared by using rigid polyurethane foam with different density as stand off layer and rubber as damping layer.The dynamic mechanical properties of the polyurethane foam and damping rubber were analyzed with DMA.The cantilever beams with stand off composite damping material and the rubber were compared and analyzed from the aspects of amplitude frequency curves,composite loss factors and modal frequencies through hamming experiment.The effect of the foams with dif ferent density on the damping performance with different densities foam was also discussed.The results showed that the loss factors of polyurethane foam were small comparing with the rubber,and its main function was to enlarge the deformation of damping layer.The modal vibration of the first three orders of the cantilever beam treated with the composite damping materials was reduced by 8%~52%,and the composite loss factors were increased by 2~3 times.The vibration was further reduced when the density of the foam increased.It was concluded that the structural vibration could be effectively reduced by treated with stand off composite damping material,and the vibration re duction performance would be improved with the foam density appropriately increased.