METHOD AND APPARATUS FOR LESS DESTRUCTIVE EVALUATION AND MONITORING OF A STRUCTURE

• US 20140309950A1
• Filed: 04/10/2014
• Published: 10/16/2014
• Est. Priority Date: 04/12/2013
• Status: Active Grant

• Current Assignee: Acellent Technologies, Inc.
• Original Assignee: Acellent Technologies, Inc.
• Inventors: CHANG, Fu-Kuo, LI, Irene, JANAPATI, Vishnuvardhan, LEE, Sang Jun
• Granted Patent: US 10,908,036 B2
• Time in Patent Office: Days
• US Class Current: 702/35
• CPC Class Codes: G01L 1/16 using properties of piezoelectric devices
• CPC Class Codes: G01M 5/0033 by determining damage, crack or wear
• CPC Class Codes: G01M 5/0066 by exciting or detecting vibration or acceleration vibration testing of structures G01M7/00

Abstract

Methods and apparatuses for monitoring a first structure at least partially according to properties of a second structure. One such method comprises determining a first relationship between a first variable and a second variable, wherein the first variable represents sizes of actual damage to the second structure, and the second variable represents sizes of simulated damage on the second structure; determining a second relationship between a third variable and a fourth variable, wherein the third variable represents sizes of simulated damage on the first structure, and the fourth variable represents values of a damage index determined for the simulated damage on the first structure; and determining an estimate of damage to the first structure according to the first and second relationships.

Claims

1. A structural health monitoring method, the method comprising:

for a second structure representative of a first structure, determining a first relationship between sizes of simulated damage on the second structure and values of a damage index determined for the simulated damage;

determining a second relationship between sizes of actual damage to the second structure and values of the damage index determined for the actual damage;

from the first and second relationships, determining a third relationship between the sizes of actual damage to the second structure and the sizes of simulated damage on the second structure; and

determining a fourth relationship between sizes of simulated damage on the first structure and values of the damage index determined for the simulated damage on the first structure.

2. The method of claim 1, further comprising:

monitoring the first structure so as to determine at least one value of the damage index for actual damage to the first structure;

substituting the at least one value of the damage index for actual damage to the first structure for the corresponding values of the damage index determined for the simulated damage of the fourth relationship, so as to determine corresponding values of the sizes of simulated damage on the first structure;

substituting the corresponding values of the sizes of simulated damage on the first structure for the corresponding values of the sizes of simulated damage on the second structure of the third relationship, so as to determine corresponding values of the sizes of actual damage to the second structure, and so as to thereby approximate the corresponding values of the sizes of actual damage to the second structure as one or more sizes of the actual damage to the first structure.

3. The method of claim 1, wherein the simulated damage on the second structure comprises damage simulators of differing sizes, each coupled to the second structure;

and wherein the simulated damage on the first structure comprises damage simulators of differing sizes, each coupled to the first structure.

4. The method of claim 3, wherein the damage simulators comprise rigid devices each having a first elongated flat side having a first length representing a length of a simulated crack, the flat side having a pointed end representing a tip of the simulated crack.

5. The method of claim 1, wherein:

the first relationship is a first curve fit to the sizes of simulated damage on the second structure;

the second relationship is a second curve fit to the sizes of actual damage to the second structure;

the third relationship is a third curve fit to the sizes of actual damage to the second structure; and

the fourth relationship is a fourth curve fit to the sizes of simulated damage on the first structure.

6. The method of claim 5, wherein at least one of the first, second, third, and fourth curves is a first degree polynomial.

7. The method of claim 5, wherein at least one of the first, second, third, and fourth curves is a power curve.

8. The method of claim 1, further comprising determining a minimum size from among the sizes of simulated damage on the first structure, the minimum size being a threshold damage size below which a corresponding size of actual damage to the first structure is disregarded.

9. A method of monitoring a first structure at least partially according to properties of a second structure, the method comprising:

determining a first relationship between a first variable and a second variable, wherein the first variable represents sizes of actual damage to the second structure, and the second variable represents sizes of simulated damage on the second structure;

determining a second relationship between a third variable and a fourth variable, wherein the third variable represents sizes of simulated damage on the first structure, and the fourth variable represents values of a damage index determined for the simulated damage on the first structure; and

determining an estimate of damage to the first structure according to the first and second relationships.

10. The method of claim 9, wherein the determining an estimate of damage to the first structure further comprises:

approximating values of the damage index determined from a monitoring of the first structure as corresponding values of the fourth variable, so as to determine from the second relationship corresponding values of the third variable;

approximating the corresponding values of the third variable as corresponding values of the second variable, so as to determine from the first relationship corresponding values of the first variable; and

approximating the corresponding values of the first variable as sizes of actual damage to the first structure.

11. The method of claim 9, wherein the simulated damage on the second structure comprises damage simulators of differing sizes, each coupled to the second structure;

and wherein the simulated damage on the first structure comprises damage simulators of differing sizes, each coupled to the first structure.

12. The method of claim 11, wherein the damage simulators comprise rigid devices each having a first elongated flat side having a first length representing a length of a simulated crack, the flat side having a pointed end representing a tip of the simulated crack.

13. The method of claim 9, further comprising determining a minimum size from among the sizes of simulated damage on the first structure, the minimum size being a threshold damage size below which a corresponding size of actual damage to the first structure is disregarded.

14. A structural health monitoring system for monitoring a first structure at least partially according to properties of a second structure, the system comprising:

a controller; and

one or more memories storing data corresponding to a first relationship between a first variable and a second variable, and a second relationship between a third variable and a fourth variable;

wherein the first variable represents sizes of actual damage to the second structure, and the second variable represents sizes of simulated damage on the second structure;

wherein the third variable represents sizes of simulated damage on the first structure, and the fourth variable represents values of a damage index determined for the simulated damage on the first structure; and

wherein the controller is configured to determine an estimate of actual damage to the first structure according to the stored data corresponding to the first and second relationships.

15. The system of claim 14, wherein the controller is further configured to:

approximate values of the damage index determined from a monitoring of the first structure as corresponding values of the fourth variable, so as to determine from the second relationship corresponding values of the third variable;

approximate the corresponding values of the third variable as corresponding values of the second variable, so as to determine from the first relationship corresponding values of the first variable; and

approximate the corresponding values of the first variable as sizes of actual damage to the first structure.

16. The system of claim 14, wherein the one or more memories further store a minimum size from among the sizes of simulated damage on the first structure, the minimum size being a threshold damage size below which a corresponding size of the estimated actual damage to the first structure is disregarded.

17. One or more non-transitory computer-readable memories, the memories collectively storing data and collectively further storing instructions for carrying out a method:

the data comprising data corresponding to a first relationship between a first variable and a second variable, and a second relationship between a third variable and a fourth variable; and

the method comprising determining an estimate of actual damage to the first structure according to the stored data corresponding to the first and second relationships;

wherein the first variable represents, for a first structure representative of a second structure, sizes of actual damage to the second structure, and the second variable represents sizes of simulated damage on the second structure; and

wherein the third variable represents sizes of simulated damage on the first structure, and the fourth variable represents values of a damage index determined for the simulated damage on the first structure.

18. The memories of claim 17, wherein the method further comprises:

approximating values of the damage index determined from a monitoring of the first structure as corresponding values of the fourth variable, so as to determine from the second relationship corresponding values of the third variable;

approximating the corresponding values of the third variable as corresponding values of the second variable, so as to determine from the first relationship corresponding values of the first variable; and

approximating the corresponding values of the first variable as sizes of actual damage to the first structure.

19. The memories of claim 17, wherein the data further comprises data corresponding to a minimum size from among the sizes of simulated damage on the first structure, the minimum size being a threshold damage size below which a corresponding estimated size of actual damage to the first structure is disregarded.