发射段阻尼环对飞轮轮体振动放大的黏弹性阻尼动力吸振抑振机理分析和实验研究

飞轮在发射段由于受到安装界面的振动与冲击,会发生振动放大现象,为抑制该振动放大,工程界提出了采用阻尼环的抑制方式。但是针对阻尼环抑振机理的研究显见公开文献发表。针对此问题,基于有限元法建立了理论模型,对发射段飞轮轮体振动放大机制和阻尼环抑振机理进行了分析;为了优化黏弹性阻尼参数,建立了飞轮-阻尼环的等效多自由度模型,给出了最优阻尼的表达式。结果表明,飞轮结构的"拍动振型模态"是其在发射段的轴向共振放大模态,导致轮体结构发生挠性大变形;阻尼环能够有效减小飞轮挠性变形的机理主要有两个:一是阻尼环的某阶模态与飞轮结构"拍动振型模态"相互作用,阻尼环充当动力吸振器;二是通过黏弹性阻尼耗能。对安装阻尼环的飞轮进行了实验研究,通过频响函数对比验证了所揭示的机理。

Theoretical analysis and tests for mechanisms of viscoelastic damping ring as a dynamic absorber and vibration amplification of flywheel in launching phase

Flywheels have vibration amplification phenomena due to vibration and shock of its installation interface in launching phase. To suppress this vibration amplification, a damping ring as a vibration-suppressing form is proposed. However, there are few literatures about damping ring vibration-suppressing mechanism published. Here, aiming at this problem, the theoretical dynamic model was established based on the finite element method to analyze a flywheel’ vibration amplification mechanism and damping ring’s vibration-suppressing one. To optimize damping ring’s viscoelastic damping parameters, an equivalent multi-DOF model for flywheel and damping ring was built to deduce the expression for optimal damping. The analysis results showed that flywheel structure’s “flapping vibration mode” is the one generating its axial resonance amplification in launching phase to cause flywheel’s large flexible deformation;damping ring has two working mechanisms of acting as a dynamic absorber to cause its one vibration mode interacting with flywheel’s flapping vibration mode, and its energy dissipation using viscoelastic damping. Tests were conducted on a flywheel installed with a damping ring. Through comparing the frequency response function obtained by theoretical analysis and that acquired with tests, the two mechanisms were verified.