流场作用下多尺度结构/材料一体化阻尼抑振仿生优化设计研究

With an urgent need of rapid and reliable vibration suppression for the components such as wing rudder and propeller in aviation and navigation areas, a ultra wide-band and multidirectional vibration suppression mechanism research of owl’s flight feather under the flow field condition was explored and a biomimetic multi-scale optimization design method of damping components with structure/material integration was proposed, drawing lessons from the owl feathers for the unique mute flight characteristics. Firstly, morphological structures and viscoelastic properties of the owl feather branches were characterized and energy dissipation theory in micro-scale was studied for the material damping vibration mechanism investigation. Meanwhile, energy transmission and dissipation mechanism based on the cross-scale multiple grade branches was explored for the research of the structural damping vibration method and its wide-band characteristic. Then, through a systematic research of the synergy vibration suppression mechanism consisted of structural damping in macro-scale and material damping in micro-scale with the influence rule of the flow field, a damping vibration model with an integration of bionic structure and viscoelastic material considering flow field effect were investigated to break through the engineering application difficulty of poor feasibility of the structure imitation caused by the large material performance difference between the biological material and conventional material, poor homogeneity of the feather material. Finally, a multi-scale optimization design method for directional bionic damping vibration structures with frequency range controlled was studied and typical vibration suppression structures based on additive manufacture technology were manufactured and the test was performed. This project aims to provide a scientific design method and a theoretical basis for the application of the bionic vibration suppression technology in the vibration control field.

面向航空航海领域高端装备对翼舵、螺旋桨叶等部件快速可靠振动抑制的迫切需求，借鉴鸮类动物（猫头鹰）独有的静音飞行特性，探索鸮翼飞羽在流场作用下超宽频、多方向阻尼减振作用机制，提出一种多尺度结构/材料一体化阻尼抑振仿生优化设计方法。首先通过鸮羽分支形态、粘弹力学特性表征和微观耗能机理研究，揭示其材料阻尼抑振机制。同时开展鸮羽多级分支间能量传递耗散规律研究，探索其结构阻尼抑振原理和宽频抑振机制。然后系统研究宏观结构阻尼、微观材料阻尼协同抑振机制及环境流体的影响规律，建立虑及流场作用的仿生结构/粘弹材料一体化阻尼减振模型，解决生物材料较常规材料性能差异大、均一性差及结构复杂等导致仿制可行性低这一工程化应用难点。最后提出一种频带范围可控的定向仿生阻尼抑振结构的跨尺度优化设计方法，并基于增材制造技术实现典型抑振结构制造与测试。以上研究旨在为仿生技术在振动控制领域的应用提供一种科学的设计方法和理论支撑。

本项目针对目前机械装备中阻尼减振装置普遍存在的工作频域窄、负载激励、环境激励和基础干扰等耦合激励作用下减振性能较差等问题，借鉴鸮类动物（猫头鹰）独有的静音飞行特性，以鸮翼飞羽为仿生原型，探索其超宽频、多方向减振作用机制，并建立一种多尺度结构/材料一体化仿生阻尼抑振优化设计方法，以探索降低或抑制宽频振动的新原理和新技术。在鸮翼飞羽抑振机理研究方面：通过鸮羽分支（羽干、羽枝、羽小枝和羽纤枝）的几何形态和粘弹力学行为表征，研究基于生物材料粘弹性特征的材料阻尼耗能机制，为等效阻尼材料的设计提供理论依据。同时，通过探讨鸮羽跨尺度多级分支间的能量传递耗散规律，研究基于鸮羽跨尺度多级分叉型式的结构阻尼抑振机理，为宽频抑振结构的设计提供理论参考。在鸮翼飞羽仿生设计研究方面：以鸮翼飞羽致密皮质层和髓质多孔介质生物特点为启发，设计并研究了变密度多层梯度点阵型金属减振结构，解决了生物材料较常规材料性能差异大、均一性差及结构复杂等导致仿制可行性低这一工程化应用难点。在仿生点阵结构的动态性能研究方面，设计了三种点阵夹芯板结构，基于有限元分析研究了点阵芯体直径和面板厚度对夹芯板固有频率的影响规律。在仿生部件的制备方面，研究了面向点阵结构和栅格翼舵的金属增材制造工艺方法，建立了激光熔覆单道几何形貌和温度场演化的三维数值模拟。基于机器学习算法优化了激光熔覆工艺参数，并实现了304不锈钢多层梯度结构和仿生栅格翼舵的制备。采用试验与有限元分析相结合的方法研究了变密度多层梯度点阵型金属减振结构的吸能性能，并进一步研究了梯度率对多层梯度结构的力学性能和吸能影响分析。本项目的研究可为仿生技术在振动控制领域的应用提供一种科学的设计方法和理论支撑。