Quantitative NDE of Advanced Composites Using Ultrasonic Velocity Measurements

1990 ◽  
Vol 112 (2) ◽  
pp. 218-222 ◽  
Author(s):  
R. A. Kline
Keyword(s):  
Ultrasonic Velocity ◽  
Composite Laminates ◽  
Isotropic Material ◽  
Numerical Procedure ◽  
Transversely Isotropic ◽  
Velocity Analysis ◽  
Velocity Measurements ◽  
Advanced Composites ◽  
Equation Solving ◽  
Quantitative Nde

In this work, the use of ultrasonic velocity analysis for the quantitative nondestructive evaluation of the mechanical properties of composite laminates is discussed. The composite laminate is modeled as a layer or set of layers of transversely isotropic material of known orientation. The method described utilizes velocity measurements for ultrasonic wave propagation at multiple angles of incidence. Since the equations are algebraically cumbersome, a numerical procedure employing a commercially available nonlinear equation solving subroutine is utilized. Applications to composite laminates are presented.

Ultrasonic velocity and anisotropy of hydrocarbon source rocks

Geophysics ◽  
1992 ◽  
Vol 57 (5) ◽  
pp. 727-735 ◽  
Author(s):  
Lev Vernik ◽  
Amos Nur
Keyword(s):  
Ultrasonic Velocity ◽  
Transversely Isotropic ◽  
Bedding Plane ◽  
Source Rocks ◽  
Small Scale ◽  
Velocity Measurements ◽  
Specific Distribution ◽  
Layer Composite ◽  
Confining Pressures ◽  
Intrinsic Anisotropy

An experimental study of the physical properties of black, kerogen‐rich shales, also including maturation analysis, scanning electron microscope (SEM) observations, and physical modeling, revealed fairly peculiar petrophysical parameters. Specifically, these rocks have very low porosity and density, but most importantly, both P and S ultrasonic velocities normal to bedding are extremely low, whereas they are much higher parallel to bedding, giving rise to a strong anisotropy even at high confining pressures. We found that these parameters primarily reflect kerogen content, microstructure, and maturation level of these rocks. We found also that microcracks inferred from ultrasonic velocity measurements occur only in mature shales. These microcracks are parallel to the bedding plane and further enhance strong intrinsic anisotropy, notably at low effective pressure. Our results show, that on a small scale, kerogen‐rich shales are transversely isotropic rocks and can be effectively modeled using the thin‐layer composite concept modified to account for the specific distribution of organic matter in the rock fabric.

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.

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