scholarly journals In-process Monitoring during Stamping of Thin Plate: Propagation Characteristics of Ultrasonic Waves in Cylindrical Stamping Dies

2019 ◽  
Vol 31 (10) ◽  
pp. 3129
Author(s):  
Naoto Hagino ◽  
Seiji Komiya ◽  
Junichi Endou ◽  
Masao Ishihama
Keyword(s):  
Thin Plate ◽  
Process Monitoring ◽  
Ultrasonic Waves ◽  
Propagation Characteristics ◽  
Stamping Dies

Effects of Briquettes with Different Crack Structures on Propagation Characteristics of Ultrasonic Waves under Wetting Conditions

2020 ◽  
Author(s):  
Gang Wang ◽  
Jinzhou Li ◽  
Huaixing Li ◽  
Zhiyuan Liu ◽  
Yanpei Guo ◽  
...  
Keyword(s):  
Particle Size ◽  
Ultrasonic Velocity ◽  
Bituminous Coal ◽  
Ultrasonic Attenuation ◽  
Crack Size ◽  
Ultrasonic Waves ◽  
Ultrasonic Frequency ◽  
Propagation Characteristics ◽  
Sample Mass ◽  
Velocity Increase

Abstract In order to examine the effect of briquettes with different crack structures on ultrasonic characteristics under different wetting conditions, a series of ultrasonic testing are carried out on briquettes at different wetting heights and the ultrasonic characteristics in these coal samples are explored. The results show that ultrasonic amplitude is positively correlated with the emission voltage, whereas ultrasonic frequency is negatively correlated with the emission voltage. Changes in both are closely related to the particle size and density. The ultrasonic velocity is positively correlated with the wetting degree. Sample mass has the greatest effect on the ultrasonic velocity, followed by particle size, and pressure has the smallest effect. At dry stage, ultrasonic velocity in gas coal is less than that in bituminous coal. The opposite is true in the fully wet state. The influence of crack thickness on ultrasonic velocity gradually increases with the wetting degree increasing. At dry stage, the velocity gradually increases with the crack dip increasing, while as the wetting height increasing, magnitude of velocity increase gradually decreases with the dip increasing. The ultrasonic attenuation in the briquettes reduces with the emission voltage enhancing. The attenuation decreases with sample particle size, crack thickness and crack size decreasing and with sample mass, pressure and crack dip increasing. The ultrasonic attenuation shows a trend of increase before decrease with the wetting height increasing. The attenuation of ultrasonic wave increases with wave velocity increasing for intact samples and shows a trend of increase before decrease for cracked samples.

scholarly journals Ultrasonic Properties of Plastically Deformed Ice

1975 ◽  
Vol 15 (73) ◽  
pp. 161-169 ◽  
Author(s):  
J. Tatibouet ◽  
R. Vassoille ◽  
J. Perez
Keyword(s):  
Plastic Deformation ◽  
Physical Properties ◽  
Sound Velocity ◽  
Single Crystals ◽  
Stress Waves ◽  
Ultrasonic Waves ◽  
Velocity Of Sound ◽  
Propagation Characteristics ◽  
Ultrasonic Properties ◽  
Crystalline Materials

AbstractMany authors have used propagation of ultrasonic waves in ice for glaciological studies. This propagation is characterized by the velocity of sound and by the attenuation of stress waves. In crystalline materials, these two characteristics depend on structural slate. In particular plastic deformation gives velocity and attenuation variations.We have measured the sound velocity and attenuation of ultrasonic waves in strained specimens of ice (single crystals and polycrystals). These measurements done between 100 and 273 K at a frequency of 5 MHz show that plastic deformation leads to an increase of attenuation arid an increase of velocity. Annealing treatments at 271 K cause recovery of propagation characteristics. The variation in attenuation can be interpreted by the theory of dislocations and this interpretation is supported by our data on the influence of frequency on this increase of attenuation induced by plastic deformation, but the theory of dislocations implies a decrease of modulus, i.e. of velocity, hence we must postulate that an added phenomenon screens the effect of dislocations. That phenomenon could be connected with ageing effects observed on different physical properties of ire and may be due to modification of protonic arrangement or creation of interstitials during plastic deformation. Thus our experiments show that it is necessary to be careful in using results determined from the propagation of ultrasonic waves in ice.

The directional propagation characteristics of elastic wave in two-dimensional thin plate phononic crystals

2007 ◽  
Vol 364 (3-4) ◽  
pp. 323-328 ◽  
Author(s):  
Jihong Wen ◽  
Dianlong Yu ◽  
Gang Wang ◽  
Honggang Zhao ◽  
Yaozong Liu ◽  
...  
Keyword(s):  
Elastic Wave ◽  
Thin Plate ◽  
Phononic Crystals ◽  
Two Dimensional ◽  
Propagation Characteristics

scholarly journals In-process Monitoring of Stamping Process of Thin Plate

2016 ◽  
Vol 57 (669) ◽  
pp. 983-990 ◽  
Author(s):  
Naoto HAGINO ◽  
Seiji KOMIYA ◽  
Junichi ENDOU ◽  
Masao ISHIHAMA
Keyword(s):  
Thin Plate ◽  
Process Monitoring ◽  
Stamping Process

THIN PLATE LAMB PROPAGATION RULE AND DISPERSION CURVE DRAWING BASED ON WAVE THEORY

2019 ◽  
Vol 26 (07) ◽  
pp. 1850222 ◽  
Author(s):  
MENG YANYU ◽  
YAN SHI
Keyword(s):  
Dispersion Curve ◽  
Thin Plate ◽  
Lamb Wave ◽  
Wave Theory ◽  
Wave Dispersion ◽  
Propagation Characteristics ◽  
Active Monitoring ◽  
Damage Degree ◽  
Text Mode ◽  
Propagation Rule

Based on the wave theory and propagation characteristics of Lamb wave in the thin plate, Lamb wave is excited by signal actuator in the thin plate and signal sensor is received in real time. Employing the superior features of dispersion curve produced the Lamb wave and combining the dichotomy iterative principle with MATLAB tools to solve Lamb wave dispersion equation, the propagation characteristics of the Lamb wave in the thin plate are plotted. It is verified that the excited Lamb wave has multimode characteristics in a certain thickness, and the different modes are related to the frequency-thickness. The wavelength-thickness ratio is defined to simplify the calculation and provide convenience for the frequency bandwidth interception of Lamb wave. The results of the theoretical analysis show that the propagation multimode of Lamb and the distribution characteristics of dispersion curve can effectively simulate the transmission information of damage signal-excited thin plate, and identify damage region and determine the damage degree by [Formula: see text] and [Formula: see text] mode. The experimental results indicate that the established method to determine damage degree of thin plate attached PZT transducers based on Lamb wave active monitoring technology can achieve a certain precision, and can make a rough quantitative recognition of damage position.

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