scholarly journals Wave Propagation Methods for Determining Stiffness of Geomaterials

10.5772/48562 ◽  
2012 ◽  
Author(s):  
Auckpath Sawangsuriya
Keyword(s):  
Wave Propagation ◽  
Propagation Methods

A novel wave propagation method for measuring viscoelastic properties of pre-strained materials

2021 ◽  
pp. 1-19
Author(s):  
Pierre Lemerle
Keyword(s):  
Wave Propagation ◽  
Viscoelastic Properties ◽  
Time History ◽  
Main Concept ◽  
Frequency Dependent ◽  
Damping Characteristics ◽  
History Of ◽  
Propagation Methods ◽  
The Time Domain ◽  
Waveform Pattern

Abstract Viscoelastic materials are widely used for vibroacoustic solutions due to their ability to mitigate vibration and sound. Wave propagation methods are based on the measurement of the waveform pattern of a transitory pulse in one-dimensional structures. The time evolution of the pattern can be used to deduce the material elasticity and damping characteristics. The most popular propagation methods, namely Hopkinson bar methods, assume no dispersion, i.e. the complex elasticity modulus is not frequency-dependent. This is not significant for resilient materials such as elastomers. More recent approaches have been developed to measure frequency-dependent properties from a pulse propagating in a slender bar. We showed in previous works how to adapt these techniques for shorter samples of materials, representing a real advance, as extrusion is a cumbersome process for many materials. The main concept was to reconstruct the time history of the wave propagating in a composite structure composed of a long incident bar made of a known material and extended by a shorter sample bar. Then the viscoelastic properties of the sample material were determined in the frequency domain within an inverse method held in the time domain. In industry, most isolation solutions using mounts or bushings must support structural weights. This is why it is particularly interesting to know the viscoelastic properties of the material in stressed state. Here, we show how to overcome this challenging issue. The theoretical framework of the computational approach is detailed and the method is experimentally verified.

2416 Predicting thermal conductivity of Si solid with molecular dynamics : comparison of non-equilibrium and wave-propagation methods

2013 ◽  
Vol 2013.26 (0) ◽  
pp. _2416-1_-_2416-2_
Author(s):  
Ryosuke KIMURA ◽  
Shuji OGATA ◽  
Ryo KOBAYASHI ◽  
Tomoyuki TAMURA ◽  
Takahisa KONO ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Wave Propagation ◽  
Propagation Methods ◽  
Non Equilibrium

A Comparative Study of Wave Excitation in Plates Using Piezoelectric Transducers Operating at Different Modes

2019 ◽  
Vol 969 ◽  
pp. 128-133 ◽  
Author(s):  
Mohammed Aslam ◽  
Praveen Nagarajan ◽  
Mini Remanan
Keyword(s):  
Wave Propagation ◽  
Lamb Waves ◽  
Primary Objective ◽  
Plate Structures ◽  
Detection Techniques ◽  
Catastrophic Failures ◽  
Different Types ◽  
Propagation Methods ◽  
Lamb Wave Propagation ◽  
Shear Horizontal

Structural health monitoring (SHM) and damage detection techniques have recently gained attention in various fields of engineering for preventing catastrophic failures. Among different SHM techniques, Lamb wave propagation methods are widely used as these waves can propagate large distance from a single source. Piezoelectric (PZT) transducers are used here as actuators and sensors to generate and receive wave signals. Most of the studies conducted on wave propagation in plates are by use of conventional d31 mode piezoelectric transducer. However, so far very few studies have been done using other types of PZT transducers. The primary objective of this paper is to determine and study the wave responses in a thin plate using different types of PZT transducers. The results indicate that the d31 and d33 type transducers generate Lamb waves, whereas d24 and d15 type transducers generate shear horizontal waves in two orthogonal directions. The study indicates that each of the transducers has its own directional property. The present study will be helpful for the application of Lamb waves and shear horizontal waves in plate structures

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