scholarly journals Dynamic Non-Destructive Evaluation of Piezoelectric Materials to Verify on Accuracy of Transversely Isotropic Material Property Measured by Resonance Method

2020 ◽  
Vol 10 (15) ◽  
pp. 5072
Author(s):  
Yu-Hsi Huang ◽  
Chien-Yu Yen ◽  
Tai-Rong Huang
Keyword(s):  
Material Property ◽  
Isotropic Material ◽  
Piezoelectric Materials ◽  
Resonance Method ◽  
Transversely Isotropic ◽  
Piezoelectric Ceramics ◽  
Resonant Frequencies ◽  
Material Constants ◽  
Non Destructive ◽  
Extension Length

In many engineering applications of piezoelectric materials, the design and prediction of the dynamic characteristics depends on the anisotropic electromechanical material property. Through collecting the complete formula in literature and listing all the prepared specimens, transversely isotropic material constants were obtained and verified by dynamic non-destructive evaluation in the paper. The IEEE (Institute of Electrical and Electronics Engineers) resonance method was applied to measure and calculate the orthotropic material constants for piezoelectric ceramics. Five specimens need to be prepared for the measurements using an impedance analyzer, in order to obtain the resonant and anti-resonant frequencies from the modes of thickness extension, length-extension, thickness-shear extension, length-thickness extension, and radial extension. The frequencies were substituted into the formulas guided on the IEEE standard to determine the elastic, dielectric, and piezoelectric constants. The dynamic characteristics of soft and hard piezoelectric ceramics in the results from the finite element method (FEM), which is analyzed from the anisotropic material constants of the resonance method, were verified with the mode shapes and natural frequencies found by experimental measurements. In self-heating, considered as operating on resonant frequencies of piezoelectric material, the resonant frequency and corresponding mode shape calculated by the material constants from resonance method in FEM are more accurate than the material property provided by the manufacturer and literature. When the wide-bandwidth frequency is needed to design the application of piezoelectric ceramics, this study completely provided the measurement method and dynamic verification for the anisotropic electromechanically material property.

Rapid Non-Destructive Testing of Ceramic Multilayer Capacitors by a Resonance Method

1988 ◽  
Vol 142 ◽  
Author(s):  
O. Boser ◽  
P. Kellawon ◽  
R. Geyer
Keyword(s):  
Acoustic Waves ◽  
High Speed ◽  
Piezoelectric Materials ◽  
Resonance Method ◽  
Test Method ◽  
Test Set ◽  
Speed Test ◽  
Multilayer Capacitors ◽  
Set Up ◽  
Non Destructive

AbstractA rapid non-destructive test method for ceramic multilayer capacitors made from piezoelectric materials such as barium titanate or lead containing materials is described and evaluated. The test method is based on the internal excitation of standing acoustic waves in the capacitors. The standing waves are severely dampened by defects such as delaminations and pores. An undampened resonance is a good indication of a defect free ceramic multilayer capacitor. This finding was used in a nondestructive test set-up to evaluate about 1,000 capacitors. The test set-up has the potential to test over 100,000 capacitors an hour. Through metallographic (cross section) examination a sorting accuracy of 2% false accepts and 8% false rejects was determined for the high speed test set-up.

THE ANALYSIS OF DYNAMICAL RESPONSE OF TRANSVERSELY ISOTROPIC MATERIAL UNDER BLASTING LOAD

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1443-1448
Author(s):  
YUE-XIU WU ◽  
QUAN-SHENG LIU
Keyword(s):  
Isotropic Material ◽  
Peak Velocity ◽  
Transversely Isotropic ◽  
Normal Direction ◽  
Dynamical Response ◽  
Transversely Isotropic Material ◽  
Peak Acceleration ◽  
Loading Direction ◽  
Blasting Load ◽  
Explosion Load

To understand the dynamic response of transversely isotropic material under explosion load, the analysis is done with the help of ABAQUS software and the constitutive equations of transversely isotropic material with different angle of isotropic section. The result is given: when the angle of isotropic section is settled, the velocity and acceleration of measure points decrease with the increasing distance from the explosion borehole. The velocity and acceleration in the loading direction are larger than those in the normal direction of the loading direction and their attenuation are much faster. When the angle of isotropic section is variable, the evolution curves of peak velocity and peak acceleration in the loading direction with the increasing angles are notching parabolic curves. They get their minimum values when the angle is equal to 45 degree. But the evolution curves of peak velocity and peak acceleration in the normal direction of the loading direction with the increasing angles are overhead parabolic curves. They get their maximum values when the angle is equal to 45 degree.

scholarly journals Elastic-plastic transition stresses in a transversely isotropic thick-walled cylinder subjected to internal pressure and steady-state temperature

2009 ◽  
Vol 13 (4) ◽  
pp. 107-118 ◽  
Author(s):  
Thakur Pankaj
Keyword(s):  
Steady State ◽  
Internal Pressure ◽  
Isotropic Material ◽  
Internal Surface ◽  
Transversely Isotropic ◽  
Percentage Increase ◽  
Transversely Isotropic Material ◽  
Elastic Plastic ◽  
Steady State Temperature ◽  
Walled Cylinder

Elastic-plastic transitional stresses in a transversely isotropic thick-walled cylinder subjected to internal pressure and steady-state temperature have been derived by using Seth's transition theory. The combined effects of pressure and temperature has been presented graphically and discussed. It has been observed that at room temperature, thick-walled cylinder made of isotropic material yields at a high pressure at the internal surface as compared to cylinder made of transversely isotropic material. With the introduction of thermal effects isotropic/transversely isotropic cylinder yields at a lower pressure whereas cylinder made of isotropic material requires less percentage increase in pressure to become fully-plastic from its initial yielding as compared to cylinder made of transversely isotropic material.

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