不同边界条件和应变振幅对各向异性层合阻尼结构内耗的影响

制备了由纤维增强树脂复合材料层与黏弹阻尼材料层交替层合的7层各向异性层合阻尼结构, 借助动态热机械分析仪(DMA Q800)首次考察了不同的结构应变振幅和不同的边界条件对该结构内耗温度频率特性的影响, 为新型减振降噪阻尼结构的理论分析与应用提供相应的实验研究依据。结果表明: 在不同的边界条件和常温(25℃)下, 各向异性层合阻尼结构的内耗都随着结构应变振幅的增加而减少, 且结构内耗峰所对应的温度随应变振幅的增加而向低温方向移动; 当结构应变振幅相同时, 单悬臂梁模式下的结构内耗最高, 双悬臂梁模式下次之, 三点弯曲模式下最低。 

Influence of different boundary conditions and strain amplitudes on the structural internal friction of anisotropic laminated damped structures

The seven layer laminated structures which are alternatively laminated by fiber reinforced composite layers and viscoelastic damping layers were prepared for providing experimental evidence for new type damping structural theory analysis and its application of vibration and noise control, and the influence of different strain amplitudes and boundary conditions on the temperature and frequency characteristics of the structural internal friction were investigated with a dynamic mechanical analyzer (DMA Q800)for the first time. The experimental results show that the structural internal friction decreases with the increasing of structural strain amplitudes under different boundary conditions at 25℃, and the temperature corresponding to the structural internal frictions peak moves towards the low-temperature with increasing the strain amplitudes. The internal frictions are maximum and second-maximum values under the single cantilever model and the double cantilever model, respectively, and the internal friction is the lowest under the 3-point bending model with the same structural strain amplitudes.