Nonlinear ultrasonic testing for non-destructive measurement of longitudinal thermal stresses in solids

Patent metadata

Field	Value
Publication number	US-9989498-B2
Application number	US-201414766219-A
Country	US
Kind code	B2
Filing date	Feb 5, 2014
Priority date	Feb 6, 2013
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

Methods and apparatus, including computer program products, are provided for nonlinear ultrasonic testing. In one aspect there is provided a method, which may include generating at least one ultrasonic wave to enable the at least one ultrasonic wave to propagate through a solid; detecting the at least one ultrasonic wave propagating through the solid; and determining a stress of the solid based on at least one of an imaginary component of a wavenumber, a wave amplitude, a wave strength, a statistical moment in a time domain, or a statistical moment in a frequency domain of the at least one ultrasonic wave.

First claim

What is claimed:

1. A method comprising:
generating, by an ultrasonic generator, at least one ultrasonic wave to enable the at least one ultrasonic wave to propagate through a rail, the at least one ultrasonic wave including an ultrasonic Rayleigh wave propagating along the surface of the rail;
measuring, by a temperature sensor, a temperature of the rail;
detecting, by a detector, the at least one ultrasonic wave including the ultrasonic Rayleigh wave propagating through the rail, the detector enabling detection of a wave strength;
determining, based at least on the measured temperature and an extrema value of the wave strength, a neutral temperature of the rail, wherein the neutral temperature of the rail represents a corresponding temperature at which a thermal stress in the rail is about zero; and
providing, to a user interface, the determined neutral temperature to provide an indication of whether the rail is in compressive stress, tensile stress, or zero stress.

2. The method of claim 1 further comprising:
normalizing the wave strength in the frequency domain of the at least one ultrasonic wave.

3. The method of claim 1 , wherein the at least one ultrasonic wave comprises an ultrasonic guided wave propagating along a predominant direction of the rail.

4. The method of claim 1 , wherein the at least one ultrasonic wave comprises an ultrasonic longitudinal wave and/or an ultrasonic shear wave propagating in one or more directions in the rail.

5. An apparatus comprising:
an ultrasonic generator configured to at least generate at least one ultrasonic wave to enable the at least one ultrasonic wave to propagate through a rail, the at least one ultrasonic wave including an ultrasonic Rayleigh wave propagating along the surface of the rail;
a detector configured to at least detect the at least one ultrasonic wave including the ultrasonic Rayleigh wave propagating through the rail, the detector enabling detection of a wave strength; and
at least one processor configured to at least
determine, based at least on a measured temperature and an extrema value of the wave strength, a neutral temperature of the rail, wherein the neutral temperature of the rail represents a corresponding temperature at which a thermal stress in the rail is about zero, and
provide, to a user interface, the determined neutral temperature to provide an indication of whether the rail is in compressive stress, tensile stress, or zero stress.

6. The apparatus of claim 5 , wherein the at least one processor is further configured to at least normalize the wave strength in the frequency domain of the at least one ultrasonic wave.

7. The apparatus of claim 5 , wherein the at least one ultrasonic wave comprises an ultrasonic guided wave propagating along a predominant direction of the rail.

8. The apparatus of claim 5 , wherein the at least one ultrasonic wave comprises an ultrasonic longitudinal wave and/or an ultrasonic shear wave propagating in one or more directions in the rail.

9. A non-transitory computer-readable medium including computer code which when executed by at least one processor circuitry provides operations comprising:
generating, by an ultrasonic generator, at least one ultrasonic wave to enable the at least one ultrasonic wave to propagate through a rail, the at least one ultrasonic wave including an ultrasonic Rayleigh wave propagating along the surface of the rail;
measuring, by a temperature sensor, a temperature of the rail;
detecting, by a detector, the at least one ultrasonic wave including the ultrasonic Rayleigh wave propagating through the rail, the detector enabling detection of a wave strength;
determining, based at least on the measured temperature and an extrema value of the wave strength, a neutral temperature of the rail, wherein the neutral temperature of the rail represents a corresponding temperature at which a thermal stress in the rail is about zero; and
providing, to a user interface, the determined neutral temperature to provide an indication of whether the rail is in compressive stress, tensile stress, or zero stress.

Assignees

• Univ California

Inventors

• Lanza Di Scalea Francesco
• Nucera Claudio

Classifications

• G01N2291/2634

  cylindrical from outside · CPC title

• G01M5/0025

  of elongated objects, e.g. pipes, masts, towers or railways (G01M5/0058 takes precedence) · CPC title

• G01M5/0041

  by determining deflection or stress · CPC title

• G01N2291/02491

  Materials with nonlinear acoustic properties · CPC title

• G01N2291/2623

  Rails; Railroads · CPC title