Composite perovskite piezoelectric ceramics of PMMN quaternary system were prepared by cold-pressing and solid-phase sintering. Piezoelectric modulus and density of the samples were measured after polarization. X-ray ...Composite perovskite piezoelectric ceramics of PMMN quaternary system were prepared by cold-pressing and solid-phase sintering. Piezoelectric modulus and density of the samples were measured after polarization. X-ray diffraction analysis and SEM were used to prove the result that the major phase of the piezoelectric ceramic spectimen based on PZT is PZT phase,which is tetragonal system and P-4mm space group.展开更多
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 ...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.展开更多
文摘Composite perovskite piezoelectric ceramics of PMMN quaternary system were prepared by cold-pressing and solid-phase sintering. Piezoelectric modulus and density of the samples were measured after polarization. X-ray diffraction analysis and SEM were used to prove the result that the major phase of the piezoelectric ceramic spectimen based on PZT is PZT phase,which is tetragonal system and P-4mm space group.
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)
文摘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.
