基于新型电涡流阻尼器的大飞机垂尾装配界面精加工振动抑制

大飞机垂尾装配界面是由钛合金制成的大型结构件，由于结构刚度低，在精加工时易产生振动、回弹变形和让刀等现象，对其精加工质量造成严重影响。为此，基于电磁感应原理设计了一款新型电涡流阻尼器用于抑制装配界面精加工中的多模态振动。首先，介绍了阻尼器的结构，并建立了其阻尼特性的理论模型。然后，基于该模型分别研究了不同磁极厚度、导体厚度和磁极数等对阻尼器阻尼特性的影响，并确定了阻尼器关键零组件的材料及几何参数。基于此，建立了装配界面抑制系统的动力学模型，并通过数值分析和有限元仿真方法得到了装配界面振动速度与阻尼器阻尼特性的变化规律。最后，通过动力学测试和切削实验对阻尼器的抑振性能进行了验证。锤击测试结果表明该阻尼器能明显提高装配界面抑振系统的阻尼比和等效刚度，阻尼比最大能提高2.17倍，等效刚度最大能提高1.65倍，能大幅衰减装配界面在冲击激励下产生的自由振动。切削实验结果表明该阻尼器能显著提升装配界面精加工过程的稳定性，装配界面时域信号的振动幅值最大能降低64.4%。通过对比实验结果得知双阻尼器配置对装配界面的抑振效果更好，能明显提高其动态可加工性，工艺参数轴向切深能提高至2.0 mm，主轴转速可提升至500 r/min，这为保证和提高装配界面的精加工质量提供了一种简单可行的解决方案。

Vibration attenuation for finishing assembly interfaces of vertical tail section of large aircraft based on novel eddy current damper

The assembly interface of the vertical tail section of large aircraft is a large thin-walled structure made of titanium alloy. Due to the low structural rigidity, it is prone to machining vibration, rebound deformation, and undercutting in the process of finishing, which seriously impacts the final finishing quality. To address these problems, a novel eddy current damper is designed based on the principle of electromagnetic induction to suppress the multi-mode vibration of the assembly interface. Firstly, the geometric structure of the damper is introduced. Then the damping performance model of the damper is established. Secondly, the effects of various thicknesses of magnetic pole, thicknesses of conductor, and numbers of magnetic poles on the damper's damping are respectively studied. And the reasonable material and the geometric parameters of key damper components are determined based on the damping performance model. Thirdly, the dynamic model of the suppression system of the assembly interface is established. Then the relationship between the vibration velocity and the damping performance of the damper is obtained through numerical analysis and finite element simulation methods. Finally, the working performance of the damper is validated via dynamic tests and cutting experiments. The dynamic tests results show the damper can improve the damping ratio and the structural stiffness of the assembly interface by 2.17 and 1.65 times respectively, greatly attenuate the free vibration of the assembly interface. The cutting experiment results illustrate the damper can increase the finishing stability of the assembly interface, such as, the vibration amplitude of the assembly interface can be reduced by 64.4% in the time domain, which shows a good vibration suppression effect. The comparison of the results shows that the configuration of double dampers possesses a better function of vibration suppression to improve the dynamic machinability of the assembly interface. That is, the axial cutting depth and the spindle speed can be respectively increased to 2.0 mm and 500 r/min, providing a suitable and feasible approach for ensuring the finishing quality of the assembly interface.