scholarly journals Reflection of transient plane step-stress waves: Some considerations of orthotropy and thermoelasticity

2011 ◽  
Vol 6 (1-4) ◽  
pp. 87-104
Author(s):  
Louis Brock
Keyword(s):  
Stress Waves ◽  
Plane Step

scholarly journals Design and Analysis of a Novel Piezoceramic Stack-based Smart Aggregate

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6438
Author(s):  
Guangtao Lu ◽  
Xin Zhu ◽  
Tao Wang ◽  
Zhiqiang Hao ◽  
Bohai Tan
Keyword(s):  
Resonance Frequency ◽  
Electromechanical Coupling ◽  
Structural Parameters ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Stress Waves ◽  
Parallel Connection ◽  
Smart Aggregate ◽  
In Series ◽  
Piezoelectric Wafers

A novel piezoceramic stack-based smart aggregate (PiSSA) with piezoceramic wafers in series or parallel connection is developed to increase the efficiency and output performance over the conventional smart aggregate with only one piezoelectric patch. Due to the improvement, PiSSA is suitable for situations where the stress waves easily attenuate. In PiSSA, the piezoelectric wafers are electrically connected in series or parallel, and three types of piezoelectric wafers with different electrode patterns are designed for easy connection. Based on the theory of piezo-elasticity, a simplified one-dimensional model is derived to study the electromechanical, transmitting and sensing performance of PiSSAs with the wafers in series and parallel connection, and the model was verified by experiments. The theoretical results reveal that the first resonance frequency of PiSSAs in series and parallel decreases as the number or thickness of the PZT wafers increases, and the first electromechanical coupling factor increases firstly and then decrease gradually as the number or thickness increases. The results also show that both the first resonance frequency and the first electromechanical coupling factor of PiSSA in series and parallel change no more than 0.87% as the Young’s modulus of the epoxy increases from 0.5 to 1.5 times 3.2 GPa, which is helpful for the fabrication of PiSSAs. In addition, the displacement output of PiSSAs in parallel is about 2.18–22.49 times that in series at 1–50 kHz, while the voltage output of PiSSAs in parallel is much less than that in parallel, which indicates that PiSSA in parallel is much more suitable for working as an actuator to excite stress waves and PiSSA in series is suitable for working as a sensor to detect the waves. All the results demonstrate that the connecting type, number and thickness of the PZT wafers should be carefully selected to increase the efficiency and output of PiSSA actuators and sensors. This study contributes to providing a method to investigate the characteristics and optimize the structural parameters of the proposed PiSSAs.

Stress waves in layered rocks

1992 ◽  
Vol 92 (1-4) ◽  
pp. 175-181 ◽  
Author(s):  
P. Borejko ◽  
H. P. Rossmanith ◽  
Y. Z. Wei
Keyword(s):  
Stress Waves

Revisiting piezoelectric sensor calibration methods using elastodynamic stress waves

2021 ◽  
Author(s):  
Rui Wu ◽  
Paul Antony Selvadurai ◽  
Chaojian Chen ◽  
Omid Moradian
Keyword(s):  
Piezoelectric Sensor ◽  
Stress Waves ◽  
Sensor Calibration ◽  
Calibration Methods

Computer Simulation of ao Screw Dislocations in Ni3Al

1990 ◽  
Vol 213 ◽  
Author(s):  
T.A. Parthasarathy ◽  
D.M. Dimiduk ◽  
C. Woodward ◽  
D. Diller
Keyword(s):  
Computer Simulation ◽  
Screw Dislocation ◽  
Elastic Anisotropy ◽  
Elastic Interaction ◽  
Embedded Atom Method ◽  
Interaction Torque ◽  
Embedded Atom ◽  
Reduced Height ◽  
Plane Step ◽  
Simulation Results

ABSTRACTDissociation of the ao<110> screw dislocation in Ni3Al was studied using the embedded atom method of computer simulation. The dissociation occurred predominantly along the {111} plane, however, a {001}-plane step occurred in the APB at the center of the configuration. When a pair of ao/2<110> superpartials initially separated in the {111} plane was relaxed, the step formed once again but with a reduced height. When the pair was relaxed from larger distances the step was not formed. The results indicate that the elastic interaction “torque” due to elastic anisotropy is responsible for the formation of the {001} APB step. When a stress was applied to these dislocation configurations by simulation, results confirmed that the step in the APB and the octahedral cross-slipped-core dissociations can be significant barriers to glide of the screw dislocation.

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