Multi-ferroic structural health monitoring systems and methods

• US 8,397,580 B2
• Filed: 09/16/2010
• Issued: 03/19/2013
• Est. Priority Date: 09/16/2010
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Georgeson, Gary E., Miller, Robert James
• Primary Examiner(s): Noori, Max
• Application Number:
  US12/883,354
• Publication Number:
  US 20120070668A1
• Time in Patent Office: 915 Days
• Field of Search: 737/60, 737/79, 738/626.9, 737/77, 737/90
• US Class Current: 73/760
• CPC Class Codes: B29C 65/4855 characterised by their physical properties, e.g. being electrically-conductive
• CPC Class Codes: B29C 65/4875 being spherical, e.g. particles or powders
• CPC Class Codes: B29C 65/489 being metals
• CPC Class Codes: B29C 65/8284 by the use of magnetic means
• CPC Class Codes: B29C 66/721 Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29K 2995/0008 Magnetic or paramagnetic
• CPC Class Codes: B29L 2031/3076 Aircrafts blades, propellers B29L2031/08
• CPC Class Codes: B64D 2045/0085 Devices for aircraft health monitoring, e.g. monitoring flutter or vibration
• CPC Class Codes: B64F 5/60 Testing or inspecting aircraft components or systems
• CPC Class Codes: G01B 7/24 using change in magnetic properties
• CPC Class Codes: G01L 1/12 by measuring variations in the magnetic properties of materials resulting from the application of stress
• CPC Class Codes: G01L 1/125 by using magnetostrictive means magnetostrictive sensors H10N35/101
• 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
• CPC Class Codes: G01M 5/0083 by measuring variation of impedance, e.g. resistance, capacitance, induction
• CPC Class Codes: G01M 5/0091 by using electromagnetic excitation or detection
• CPC Class Codes: G01R 33/098 comprising tunnel junctions, e.g. tunnel magnetoresistance sensors
• CPC Class Codes: G01R 33/1269 of molecules labeled with magnetic beads magnetic particles for bio assay G01N33/54326
• CPC Class Codes: G08C 17/02 using a radio link
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]

Abstract

A method for testing a multiple layer structure is described. The method includes monitoring strains experienced by strain sensitive, magnetic particles disbursed within an adhesive between a first layer and a second layer, and analyzing any changes in the strains experienced by the particles to determine an amount of damage or degradation to the structure.

Claims

1. A method for testing a multiple layer structure, said method comprising:

periodically interrogating a plurality of multiferroic sensors dispersed on a first surface of a first layer of the structure to monitor strains experienced by strain sensitive, magnetic particles dispersed within an adhesive between a second surface of the first layer and a second layer; and

analyzing any changes in the strains experienced by the particles to determine an amount of damage or degradation to the structure.

2. The method according to claim 1 wherein analyzing any changes in the strains comprises analyzing changes in the responses to interrogation.

3. The method according to claim 1 wherein periodically interrogating multiferroic sensors comprises interrogating individual multiferroic sensors using RFID.

4. The method according to claim 1 further comprising dispersing the individual multiferroic sensors to provide overlapping coverage for the strain sensitive, magnetic particles.

5. The method according to claim 1 further comprising dispersing the strain sensitive, magnetic particles at least 0.01 inch apart in the adhesive throughout an area of the structure to be monitored.

6. The method according to claim 1 wherein monitoring strains comprises at least one of sensing a magnetization level of the magnetic particles and sensing a magnetic permeability of the magnetic particles.

7. The method according to claim 1 further comprising monitoring strains experienced by strain sensitive, magnetic particles dispersed throughout the multiple layer structure.

8. The method according to claim 7 further comprising comparing the monitored strains with a baseline to inspect for manufacturing defects in the multiple layer structure.