基于靶能量传递的非线性动量轮吸振器研究

The micro-vibration from momentum wheels (MWs), as the one of main distrubances, has restricted the effective use of high sensitive payloads in the satellite. In order to suppress the low-frequency line spectrum from MWs, the nonlinear tuned vibration absorber (NOVIB) based on passive nonlinear targeted energy transfer (TET) mechanism is developed. The proposed NOVIB is to be attached on the supporting plate of momentum wheels assembly (MWA), aiming to attenuate the line spectrum introduced by MWs in operation. This project will set up the governing equation of discrete multi-degree-of-freedom dynamic model of NOVIB, MWs-MWA and satellite structural part by taking into account of the gyroscopic effect of MWs; the frequency-energy topological structure can be obtained by solving the periodic orbit solutions of the undamped system; and the time-series motion responses, as well as instantaneous energy transfer in the system can be acquired by solving the damped system. Based on the fundamental theories of NOVIB and the frequency-energy topological structure of the system, the project will developed the effective analysis methods for the designing by employing bifurcation analysis, and investigate the dynamic mechanism for TET, as well as analyze the necessary initial conditions to fulfill the TET and establish the design criteria for avoiding some of the response that are contrary to the design objectives. Essentially nonlinear stiffness elements by employing curved beams are advanced, designed and applied for on-orbit micro-vibration suppression of momentum wheels. Experimental studies are carried out to validate the TET mechanism phenonmenon and the effectiveness of the engineering application.

动量轮运转产生的微振动是影响星载有效载荷工作性能的主要干扰源之一。针对动量轮的低频线谱干扰，提出基于靶能量传递的非线性动力吸振器，布置于动量轮组件的支撑平台，对动量轮在轨运行产生的干扰进行吸振。考虑动量轮旋转时的陀螺效应，建立非线性动力吸振器和动量轮-支撑平台-卫星结构耦合的离散多自由度系统动力学模型，通过求解无阻尼系统的周期解得到系统的频率-能量谱图，通过求解阻尼系统的运动时程响应得到系统响应和能量的传递情况。基于非线性动力吸振的基本理论和系统的能量-频率图，发展通过分岔分析对非线性动力吸振器进行设计的有效计算方法，揭示非线性动力吸振机理；分析能量在非线性耦合振子之间实现靶能量传递的条件，建立避免系统出现与设计目标相违背响应的准则。提出基于曲梁的本质非线性刚度实现方法，建立包含模拟扰源-吸振器系统的地面试验系统，验证所提出非线性吸振器的有效性和理论研究成果。

星上飞轮系统工作时产生的输出扰振是在轨航天器的主要振动源之一，将极大影响星上有效载荷的工作性能。本项目从理论分析和实验研究两个角度揭示了利用金属薄片梁构建的非线性动力吸振器发生靶能量传递机理和非线性刚度机理，取得了如下研究成果：.在理论上，分别建立了双边简支并联金属薄片梁和双边固支单根金属薄片梁作为非线性刚度元件的非线性吸振器系统动力学模型，获得了其非线性刚度输出特征及主要影响因素、在不同类型激励作用下系统动态响应特性，明确了其非线性刚度实现方式和激发靶能量传递的机制。.在实验上，通过飞轮安装在刚性边界和柔性边界上的振动实验，获得飞轮与支撑系统耦合的输出扰振特性；通过瞬态载荷和飞轮恒定转速产生的稳态载荷作用，获得安装非线性吸振器前后系统的响应特性；进而，发现了非线性吸振器的非线性振动特征和发生靶能量传递与初始输入能量之间的关系。.以上两方面的研究表明：（1）非线性吸振器可有效抑制飞轮输出扰振引起的振动响应；（2）非线性吸振器发生靶能量传递存在典型的阈值特征，通过调整初始输入能量和非线性吸振器设计参数均可激发靶能量传递；（3）采用金属薄片梁作为非线性刚度元件，其动态特性稳定，系统质量小。因此，所提出的非线性吸振器具有较好的工程应用价值。.此外，在本项目资助下，课题组在国内外期刊、会议共计发表学术论文11篇，其中EI期刊收录6篇；申请国家发明专利1项；培养硕士研究生1名；协助1名团队成员获评副高级职称。