Zhang Qiang, Piao Shengchun, Chen Hongjuan
Acoustic Science and Technology Laboratory, Harbin Engineering University, Harbin 150001, China.
Acoustic Science and Technology Laboratory, Harbin Engineering University, Harbin 150001, China.
Ultrasonics. 2021 Jul;114:106428. doi: 10.1016/j.ultras.2021.106428. Epub 2021 Apr 2.
A theoretical model of the intermittent contact mechanism of linear piezoelectric actuator was proposed, in which the microscopic characteristics of the contact surfaces were taken into account. Greenwood-Williamson (GM) theory was involved for the first time to describe the microscopic characteristics of the contact surfaces in which the contact surfaces were considered as random rough surfaces that were composed of large amounts of asperities and the heights of the asperities conformed to a Gauss distribution. The developed theoretical model gives an insight into the influence of the microscopic properties, as well as the macroscopic and material properties on the output performance of the actuator, which may provide guidance for the design of such type of piezoelectric actuator. During the modeling, normal kinetic contact force, kinetic friction coefficient, friction force and steady-state output force of were obtained in sequence. And some simulations were carried out to analyze how factors such as the type of material, the roughness of the contact surface, the initial distance between the stator and the rotor, and the preload, et.al, affect the contact performance. A set of experiments were carried out to reveal the influence of surface roughness, material type and preload on the steady-state output thrust. The simulated results were found in good agreement with the experiment ones at most of the tested points. Finally, surface roughness of the stator and rotor were tested before and after the operation, which indicated that the rotor and stator had similar roughness after operation.
提出了一种线性压电致动器间歇接触机制的理论模型，其中考虑了接触表面的微观特性。首次引入格林伍德-威廉姆森（GM）理论来描述接触表面的微观特性，该理论将接触表面视为由大量微凸体组成的随机粗糙表面，且微凸体的高度符合高斯分布。所建立的理论模型深入探讨了微观特性以及宏观和材料特性对致动器输出性能的影响，可为这类压电致动器的设计提供指导。在建模过程中，依次获得了法向动接触力、动摩擦系数、摩擦力和稳态输出力。并进行了一些模拟，以分析材料类型、接触表面粗糙度、定子与转子之间的初始距离以及预载荷等因素如何影响接触性能。进行了一组实验，以揭示表面粗糙度、材料类型和预载荷对稳态输出推力的影响。发现在大多数测试点，模拟结果与实验结果吻合良好。最后，对定子和转子运行前后的表面粗糙度进行了测试，结果表明运行后转子和定子具有相似的粗糙度。
