METHOD AND APPARATUS FOR NONDESTRUCTIVE EVALUATION AND MONITORING OF MATERIALS AND STRUCTURES

• US 20090204344A1
• Filed: 10/14/2008
• Published: 08/13/2009
• Est. Priority Date: 02/07/2008
• Status: Active Grant

• Current Assignee: California Institute of Technology, University Of Pittsburgh (University of Pittsburgh of The Commonwealth System of Higher Education)
• Original Assignee: California Institute of Technology
• Inventors: Daraio, Chiara, Rizzo, Piervincenzo
• Granted Patent: US 8,327,709 B2
• Time in Patent Office: Days
• US Class Current: 702/39
• CPC Class Codes: G01N 29/045 by imparting shocks to the workpiece and detecting the vibrations or the acoustic waves caused by the shocks measuring resonant frequency G01H13/00; measuring strength properties by application of mechanical stress G01N3/00
• CPC Class Codes: G01N 29/2431 using other means for acoustic excitation, e.g. heat, microwaves, electron beams sound producing devices not otherwise provided for G10K15/04
• CPC Class Codes: G01N 29/2437 Piezoelectric probes
• CPC Class Codes: G01N 29/341 with time characteristics
• CPC Class Codes: G01N 29/343 pulse waves, e.g. particular sequence of pulses, bursts

Abstract

A method and apparatus for nondestructive evaluation (NDE) of structures and materials using a highly nonlinear medium for the generation and detection of one or multiple highly nonlinear pulses (or highly nonlinear waves) impinging on a material or structure. The apparatus includes pulse exciters that induce the propagation of highly nonlinear, weakly nonlinear or linear stress waves in the material, system, or structure to be inspected and/or detectors for the observation and the detection of the output waves from the material/structure being tested. The NDE method includes the use of the tunable highly nonlinear apparatus as impulse exciter alone, or in combination with an accelerometer or a nonlinear sensor to detect the outgoing pulse.

Claims

1. A method for performing an inspection of an element or structure comprising:

generating one or more highly nonlinear waves;

directing the one or more highly nonlinear waves into the element or structure to be inspected; and

,

detecting pulses deriving from the waves directed into the element or structure after the waves have propagated through at least a portion of the element or structure to be inspected.

2. The method according to claim 1, wherein generating highly nonlinear waves comprises directing a pulse or pulses into a chain of spherical particles, wherein each particle in the chain of spherical particles is in linear contact with adjacent particles in the chain.

3. The method according to claim 2, wherein the particles in the chain of particles are linearly constrained and are compressed in the linear direction.

4. The method according to claim 3, wherein a desired wavelength, speed, number of pulses, and/or amplitude of the highly nonlinear wave generated by the chain of particles is controlled by selection of one or more of the following:

number of particles in the chain of particles;

size or sizes of particles in the chain of particles;

material comprising the particles; and

amount of static precompression.

5. The method according to claim 2, wherein at least one particle in the chain of particles comprises at least one of the following detection elements:

a wave detection element;

a pressure detection element;

an acceleration detection element, or a displacement detection element.

6. The method according to claim 1, wherein the one or more highly nonlinear waves comprise one or more highly nonlinear solitary waves.

7. A system for inspecting an element or structure comprising:

a highly nonlinear wave actuator, wherein the actuator is configurable to impinge highly nonlinear pulses to the element or structure to be inspected, and

a pulse detector configurable to detect pulses from the actuator propagating through at least a portion of the element or structure to be inspected.

8. The system according to claim 7, wherein the highly nonlinear wave actuator comprises:

a chain of spherical particles and

a striking apparatus configured to strike a first particle in the chain of particles.

9. The system according to claim 8, wherein the highly nonlinear wave actuator further comprises a precompression apparatus configured to apply a compressive force along a linear direction of the chain of spherical particles.

10. The system according to claim 8, at least one particle in the chain of particles comprises at least one of the following detection elements:

a wave detection element;

a pressure detection element;

an acceleration detection element, or a displacement detection element.

11. The system according to claim 7 further comprising a processor configured to receive generated pulse data from the highly nonlinear wave actuator and configured to receive received pulse data from the pulse detector, wherein the processor compares the received pulse data with the generated pulse data to determine inspection results.

12. The system according to claim 7, wherein the highly nonlinear wave actuator generates one or more highly nonlinear solitary waves.

13. A method for performing an inspection of an element or structure comprising:

generating an inspection pulse;

directing the inspection pulse into the element or structure to be inspected;

directing the inspection pulse after it has propagated through at least a portion of the element or structure to be inspected into a nonlinear receiver; and

detecting the inspection pulse after it has propagated through at least a portion of the nonlinear receiver.

14. The method according to claim 13 wherein the nonlinear receiver comprises a chain of spherical particles, wherein each particle in the chain of spherical particles is in linear contact with adjacent particles in the chain.

15. The method according to claim 14, wherein the particles in the chain of particles are linearly constrained and are compressed in the linear direction.

16. The method according to claim 14, wherein detecting the inspection pulse comprises detecting the inspection pulse with at least one particle in the chain of particles comprising at least one of the following detection elements:

a wave detection element;

a pressure detection element;

an acceleration detection element, or a displacement detection element.

17. The method according to claim 14, wherein detecting the inspection pulse comprises directing the inspection pulse into an end of the chain of particles adjacent to the element or structure to be inspected and detecting the inspection pulse at an end of the chain of particles opposite to the end adjacent to the element or structure to be inspected.

18. A system for inspecting an element or structure comprising:

a pulse actuator, wherein the actuator is configurable to apply pulses to the element or structure to be inspected, and

a nonlinear receiver configurable to detect pulses from the actuator propagating through at least a portion of the element or structure to be inspected.

19. The system according to claim 18, wherein the nonlinear receiver comprises a chain of spherical particles, wherein each particle in the chain of spherical particles is in linear contact with adjacent particles in the chain.

20. The system according to claim 19, wherein the particles in the chain of particles are linearly constrained and are compressed in the linear direction.

21. The system according to claim 19, wherein at least one particle in the chain of particles comprises at least one of the following detection elements:

a wave detection element;

a pressure detection element;

an acceleration detection element, or a displacement detection element.

22. The system according to claim 19, wherein the nonlinear receiver comprises at least one detection element disposed at an end of the chain of particles, wherein the detection element comprises at least one of the following detection elements:

a wave detection element;

a pressure detection element;

an acceleration detection element, or a displacement detection element.