Parametric studies of composite material properties influence on dispersion curves of Lamb waves

2020 ◽  
Author(s):  
Pawel Kudela ◽  
Piotr Fiborek ◽  
Maciej Radzienski ◽  
Tomasz Wandowski
Keyword(s):  
Composite Material ◽  
Material Properties ◽  
Lamb Waves ◽  
Dispersion Curves ◽  
Parametric Studies

Dielectric and Mechanical Loading Effects of a Fluid on Lamb Waves Propagating in an Immersed Piezoelectric Plate

2005 ◽  
Vol 21 (3) ◽  
pp. 179-186 ◽  
Author(s):  
C.-H. Yang ◽  
Y.-A. Lai
Keyword(s):  
Lamb Waves ◽  
Piezoelectric Plate ◽  
Dispersion Curves ◽  
Partial Wave Analysis ◽  
Theoretical Treatment ◽  
Fluid Loading ◽  
Wave Analysis ◽  
Sensor Applications ◽  
Dielectric Loading ◽  
Loading Effects

AbstractThis research is focused on exploring the fluid loading effects on the dispersion curves of Lamb modes propagating in a piezoelectric plate. A theoretical treatment based on a partial wave analysis is developed to model the dispersion curves of Lamb modes propagating in an X-LiNbO3 plate loaded by a fluid with combined mechanical/dielectric properties. In particular, the mode-shifting characteristics caused by the fluid loading as a function of the propagation orientation are illustrated with numerical examples. Finally, for the case of water as an immersing fluid, individual attributions of the mechanical and dielectric loading effects causing the mode-shifting are analyzed. It is found that the dielectric loading effect dominates the mode-shifting while the mechanical density loading can be neglected while Lamb waves propagate in an X-LiNbO3 plate immersing in water. The current results provides useful information for the applications of acoustic plate mode (APM) devices used in liquid sensor applications.

Noncontact Evaluation of Defects in Thin Plate With Multimodes Lamb’s Waves and Wavelet Transform

2002 ◽  
Author(s):  
Morimasa Murase ◽  
Koichiro Kawashima
Keyword(s):  
Group Velocity ◽  
Thin Plate ◽  
Wavelet Transformation ◽  
Velocity Dispersion ◽  
Lamb Waves ◽  
Group Velocity Dispersion ◽  
Dispersion Curves ◽  
Contact Method ◽  
Intact Specimen ◽  
Time Frequency

Multimode’s Lamb waves in aluminum plates with various defects were excited by a Q-switched Nd:YAG laser. The Lamb waves past through the defects were received a laser interferometer. The received signals of the Lamb waves are processed by the wavelet transformation. The wavelet transformation is generally shown on the time-frequency domain. By dividing a propagation distance by the time, the group velocities are identified. In this way, group velocity dispersion maps of multimode’s Lamb waves are constructed with the received temporal signals. By changing the shape of the mother wavelet, Gabor function, we can identify the dispersion curves of the higher mode Lamb waves. The group velocity dispersion maps of a intact specimen agree well on theoretical dispersion curves of S0, A0, S1, A1, S2, A2, and A3 modes. The difference between the dispersion maps of the intact specimen and that with defects clearly visualizes the existence of defects. This non-contact method is effective for inspecting various defects in thin plate structures.

Influence of Rubber Particle Size on Functional Properties of a Composite Material Based on Scrap Tires and a Polymer Binder

2020 ◽  
Vol 850 ◽  
pp. 107-111
Author(s):  
Laimonis Mālers ◽  
Agnija Cirvele
Keyword(s):  
Particle Size ◽  
Composite Material ◽  
Functional Properties ◽  
Material Properties ◽  
Rubber Particle ◽  
Polymer Binder ◽  
Scrap Tires ◽  
Elongation At Break ◽  
Rubber Particles ◽  
Purposeful Selection

Functional properties of composite material based on mechanically grinded scrap tires with different particle size of fractioned crumb and polyurethane type polymer binder were investigated to estimate influence of rubber particles size and content on composite material properties (Shore C hardness, compressive stress at 10 % deformation, tensile strength, elastic modulus and elongation at break, apparent density). Optimization possibilities of composite material consisting of rubber particles with different sizes or fractions were investigated. The obtained results show that variation of composition of the composite material by changing size of rubber granulate have definite influence on selected properties of the material. Purposeful selection and mutual combination of rubber particles size included in material can ensure desirable and predictable mechanical properties of composite material.

scholarly journals Advanced Composite Fan Blade Flight Evaluation Program

1976 ◽  
Author(s):  
M. H. Chopin
Keyword(s):  
Composite Material ◽  
Air Force ◽  
Material Properties ◽  
Metal Matrix ◽  
Matrix Composites ◽  
Basic Design ◽  
Turbine Engine ◽  
Advanced Composite ◽  
Advanced Composite Materials ◽  
Fan Blade

The preparation for and conduct of the first flight by the U. S. Air Force of a turbine engine fan stage fabricated of advanced composite materials is discussed. Composite material properties and basic design philosophy is presented along with preliminary flight evaluation results. This is the first application of filamentary-reinforced metal matrix composites to a turbine engine structural component.

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