Determination of remaining useful life of gas turbine blade

• US 7,555,951 B2
• Filed: 05/24/2006
• Issued: 07/07/2009
• Est. Priority Date: 05/24/2006
• Status: Expired due to Fees

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Chougule, Hasham H., Ganguli, Ranjan, Viswanathan, Sundararajan, Shadman, Andleeb, Sainudeen, Rafeek
• Primary Examiner(s): Williams; Hezron
• Assistant Examiner(s): SAINT SURIN, JACQUES M
• Application Number:
  US11/439,546
• Publication Number:
  US 20070272018A1
• Time in Patent Office: 1,140 Days
• Field of Search: 735/79, 736/02, 735/93, 736/59, 736/60, 736/62, 737/86, 737/99, 702 34- 36, 702/56
• US Class Current: 73/579
• CPC Class Codes: G01H 1/006 of the rotor of turbo machines
• CPC Class Codes: G01H 1/14 Frequency

Abstract

A system may be used to indicate a need for replacement of a vibrating structure and includes a sensor, an indicator, and a processor. The sensor senses a frequency of vibration of the vibrating structure. The indicator is controlled to provide an indication of the need for replacement of the vibrating structure. The processor compares the frequency of vibration of the vibrating structure to data that relates the vibration frequency of the vibrating structure to fatigue damage of the vibrating structure, and controls the indicator based on the comparison.

Claims

1. A system for indicating a need for replacement of a vibrating structure comprising:

a sensor arranged to sense a frequency of vibration of the vibrating structure;

an indicator that is controlled to provide an indication of the need for replacement of the vibrating structure; and

,

a processor that compares the sensed frequency of vibration of the vibrating structure to a reference frequency that relates the vibration frequency of the vibrating structure to fatigue damage of the vibrating structure and controls the indicator when the sensed frequency compares unfavorably with the reference frequency.

2. The system of claim 1 wherein the vibrating structure comprises a turbine blade.

3. The system of claim 1 further comprising a memory that stores the reference frequency.

4. The system of claim 1 wherein the vibrating structure comprises a turbine blade, and wherein the system further comprises a memory that stores the reference frequency.

5. A method comprising:

generating a model of a vibrating structure;

generating a fatigue damage model for the vibrating structure;

modifying the model of the vibrating structure based on the fatigue damage model;

determining from the modified model at least one frequency of vibration that corresponds to a predetermined amount of fatigue damage; and

,

storing the at least one frequency of vibration in a memory of a system to be used to provide a notification of when the vibrating structure should be replaced.

6. The method of claim 5 wherein the modifying of the model of the vibrating structure based on the fatigue damage model comprises:

determining Young'"'"'s modulus from the fatigue damage model; and

,

inserting the Young'"'"'s modulus into the blade model.

7. The method of claim 5 wherein the determining from the modified model of at least one frequency of vibration that corresponds to a predetermined amount of fatigue damage comprises:

computing a stiffness and a mass from the modified model; and

,

determining the at least one frequency of vibration from the stiffness and the mass.

8. The method of claim 7 wherein the modifying of the model of the vibrating structure based on the fatigue damage model comprises:

determining Young'"'"'s modulus from the fatigue damage model; and

,

inserting the Young'"'"'s modulus into the blade model.

9. The method of claim 5 wherein the vibrating structure comprises a turbine blade.

10. The method of claim 9 wherein the modifying of the model of the vibrating structure based on the fatigue damage model comprises:

determining Young'"'"'s modulus from the fatigue damage model; and

,

inserting the Young'"'"'s modulus into the blade model.

11. The method of claim 9 wherein the determining from the modified model of at least one frequency of vibration that corresponds to a predetermined amount of fatigue damage comprises:

computing a stiffness and a mass from the modified model; and

,

determining the at least one frequency of vibration from the stiffness and the mass.

12. The method of claim 11 wherein the modifying of the model of the vibrating structure based on the fatigue damage model comprises:

determining Young'"'"'s modulus from the fatigue damage model; and

,

inserting the Young'"'"'s modulus into the blade model.

16. The method of claim 5 wherein the modifying of the model of the vibrating structure based on the fatigue damage model comprises:

determining Young'"'"'s modulus from the fatigue damage model; and

,

inserting the Young'"'"'s modulus into the blade model.

13. A computer implemented method comprising:

generating a model of a vibrating structure;

generating a fatigue damage model for the vibrating structure;

modifying the model of the vibrating structure based on the fatigue damage model; and

,

determining from the modified model at least one frequency of vibration that corresponds to a predetermined amount of fatigue damage.

14. The method of claim 13 wherein the modifying of the model of the vibrating structure based on the fatigue damage model comprises:

determining Young'"'"'s modulus from the fatigue damage model; and

,

inserting the Young'"'"'s modulus into the blade model.

15. The method of claim 13 wherein the determining from the modified model of at least one frequency of vibration that corresponds to a predetermined amount of fatigue damage comprises:

computing a stiffness and a mass from the modified model; and

,

determining the at least one frequency of vibration from the stiffness and the mass.

17. The method of claim 13 wherein the vibrating structure comprises a turbine blade.

18. The method of claim 17 wherein the modifying of the model of the vibrating structure based on the fatigue damage model comprises:

determining Young'"'"'s modulus from the fatigue damage model; and

,

inserting the Young'"'"'s modulus into the blade model.

19. The method of claim 17 wherein the determining from the modified model of at least one frequency of vibration that corresponds to a predetermined amount of fatigue damage comprises:

computing a stiffness and a mass from the modified model; and

,

determining the at least one frequency of vibration from the stiffness and the mass.

20. The method of claim 19 wherein the modifying of the model of the vibrating structure based on the fatigue damage model comprises:

determining Young'"'"'s modulus from the fatigue damage model; and

,

inserting the Young'"'"'s modulus into the blade model.