纤维角度对变角度层合板减振性能的影响

自动铺丝技术可以实现复杂曲率曲线铺放，可极大提高角度设计的自由度。本文以改善复合材料层合板动态特性为目的，对变角度层合板的减振性能进行了研究分析。首先对不同角度变化变角度层合板进行自由衰减试验，研究了纤维角度变化与变角度层合板阻尼比的关系。然后对含相应角度变角度夹层板进行随机试验，研究了层合板随机激励条件下的振动响应，并采用共振峰处传递函数(Transition function，TF)和拾振点加速度总均方根(Root mean square，RMS)两种指标评价减振效果。结果表明:层合板阻尼比在纤维变化角度为±<45|60>时最大，纤维变化角度为±<73|88>时最小。基于RMS减振评价指标，±<45|60>夹层板较传统直线板减振性能提高27.13%；基于共振峰TF减振评价指标，纤维角度变化对不同共振峰减振效果规律差异明显。研究表明，变角度层合板减振性能明显优于传统直线层合板，相关实验结果将对变角度层合板减振设计及优化提供一定的参考意义。 

Influences of fiber angle on the vibration damping performance of variable angle laminates

With the development of automated fiber placement technology, it is possible to lay complex curves which greatly increase the freedom of angle design. In this paper, with the purpose of improving the dynamic characteristics of composite laminates, the vibration damping performance of variable angle laminates was studied and analyzed. Firstly, the free attenuation experiment was carried out to study the relationship between the change of fiber angle and damping ratio of variable angle laminates. Then, the vibration response of variable angle laminates under random excitation was studied by random experiments. The transition function (TF) at the formant and the root mean square (RMS) of the acceleration at the pick-up point of vibration were used to evaluate the effect of vibration reduction. The results show that the damping ratio of laminates is the largest when the fiber angle is ±<45|60> and the least when the fiber angle is ±<73|88>. Based on the vibration reduction evaluation index of RMS, the vibration reduction performance of ±<45|60> sandwich laminate is 27.13% higher than the traditional linear laminate; Based on the formant vibration reduction evaluation index of TF, the vibration reduction effect of different formants is obviously different with the fiber change. The results show that the vibration reduction performance of the variable angle laminates is obviously better than that of the traditional linear laminates. The relevant experimental results will be helpful for the design and optimization of vibration reduction of variable angle laminates.