A comparative study of piezoelectric unimorph and multilayer actuators as stiffness sensors via contact resonance  

作　　者：Ji Fu Fa-Xin Li 

机构地区：[1]State Key Laboratory for Turbulence and Complex System,College of Engineering, Peking University

出　　处：《Acta Mechanica Sinica》2016年第4期633-639,共7页力学学报（英文版）

基　　金：financial support of the National Natural Science Foundation of China (Grant11090331);Support from the Chinese National Programs for Scientific Instruments Research and Development (Grant 2012YQ03007502)

摘　　要：Piezoelectric bar-shaped resonators were proposed to act as hardness sensors in the 1960 s and stiffness sensors in the 1990 s based on the contact impedance method.In this work, we point out that both multilayer and unimorph（or bimorph） piezoelectric actuators could act as stiffness/modulus sensors based on the principle of mechanical contact resonance. First, the practical design and the performance of a piezoelectric unimorph actuator–based stiffness sensor were presented. Then the working principle of piezoelectric multilayer actuator–based stiffness sensors was given and verified by numerical investigation. It was found that for these two types of resonance-based sensors, the shift of the resonance frequency due to contact is always positive, which is different from that of the contact impedance method. Further comparative sensitivity study indicated that the unimorph actuator–based stiffness sensor is very suitable for measurement on soft materials, whereas the multilayer actuator–based sensor is more suitable for hard materials.Piezoelectric bar-shaped resonators were proposed to act as hardness sensors in the 1960 s and stiffness sensors in the 1990 s based on the contact impedance method.In this work, we point out that both multilayer and unimorph（or bimorph） piezoelectric actuators could act as stiffness/modulus sensors based on the principle of mechanical contact resonance. First, the practical design and the performance of a piezoelectric unimorph actuator–based stiffness sensor were presented. Then the working principle of piezoelectric multilayer actuator–based stiffness sensors was given and verified by numerical investigation. It was found that for these two types of resonance-based sensors, the shift of the resonance frequency due to contact is always positive, which is different from that of the contact impedance method. Further comparative sensitivity study indicated that the unimorph actuator–based stiffness sensor is very suitable for measurement on soft materials, whereas the multilayer actuator–based sensor is more suitable for hard materials.

关 键 词：piezoelectric stiffness multilayer actuator modulus hardness impedance shaped diamond verified 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]