Bondline embedded current sensor

• US 9,267,906 B2
• Filed: 07/21/2014
• Issued: 02/23/2016
• Est. Priority Date: 04/12/2011
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Anway, Carol E., Robb, Andrew M., Ihn, Jeong-Beom
• Primary Examiner(s): Desta, Elias
• Application Number:
  US14/337,095
• Publication Number:
  US 20140327433A1
• Time in Patent Office: 582 Days
• US Class Current: 1/1
• CPC Class Codes: B29C 65/483 Reactive adhesives, e.g. chemically curing adhesives
• CPC Class Codes: B29C 65/4835 Heat curing adhesives
• CPC Class Codes: B29C 65/5021 being multi-layered
• CPC Class Codes: B29C 65/5028 being textile in woven or non-woven form
• CPC Class Codes: B29C 65/5057 positioned between the surfaces to be joined B29C65/5035 takes precedence
• CPC Class Codes: B29C 65/8276 by the use of electric means
• CPC Class Codes: B29C 65/8284 by the use of magnetic means
• CPC Class Codes: B29C 65/8292 by the use of ultrasonic, sonic or infrasonic waves
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/45 Joining of substantially the whole surface of the articles methods or apparatus for laminating B32B37/00
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/721 Fibre-reinforced materials B29C66/729 takes precedence
• CPC Class Codes: B29C 66/7212 characterised by the composition of the fibres
• CPC Class Codes: B29C 66/72141 Fibres of continuous length
• CPC Class Codes: B29C 66/72143 Fibres of discontinuous lengths
• CPC Class Codes: B29C 66/7392 characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/7394 characterised by the material of at least one of the parts being a thermoset
• CPC Class Codes: B29C 66/73941 characterised by the materials of both parts being thermosets
• CPC Class Codes: B29K 2023/00 Use of polyalkenes or derivatives thereof as moulding material
• CPC Class Codes: B29K 2027/12 : containing fluorine
• CPC Class Codes: B29K 2063/00 : Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 : Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/206 : Meshes, lattices or nets
• CPC Class Codes: B29K 2277/10 : Aromatic polyamides [Polyaramides] or derivatives thereof
• CPC Class Codes: B29K 2301/00 : Use of unspecified macromolecular compounds as reinforcement use of unspecified rubbers B29K2221/00
• CPC Class Codes: B29K 2305/00 : Use of metals, their alloys or their compounds, as reinforcement
• CPC Class Codes: B29K 2307/02 : Boron
• CPC Class Codes: B29K 2307/04 : Carbon
• CPC Class Codes: B29K 2309/02 : Ceramics
• CPC Class Codes: B29K 2309/08 : Glass
• CPC Class Codes: B29L 2031/3076 : Aircrafts blades, propellers B29L2031/08
• CPC Class Codes: B29L 2031/3079 : Cockpits, canopies
• CPC Class Codes: B29L 2031/3082 : Fuselages
• CPC Class Codes: B29L 2031/3085 : Wings
• CPC Class Codes: B64C 2001/0072 : from composite materials
• CPC Class Codes: B64C 3/20 : Integral or sandwich constructions
• CPC Class Codes: B64D 2045/0085 : Devices for aircraft health monitoring, e.g. monitoring flutter or vibration
• CPC Class Codes: B64D 45/00 : Aircraft indicators or protectors not otherwise provided for camouflage F41H3/00
• CPC Class Codes: F16B 11/006 : by gluing gluing of plastics material B29C65/48
• CPC Class Codes: G01M 5/0033 : by determining damage, crack or wear
• 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: G01N 27/025 : a current being generated within the material by induction
• CPC Class Codes: G01N 27/026 : Dielectric impedance spectroscopy electrochemical impedance spectroscopy for measuring corrosion G01N17/02
• CPC Class Codes: G01N 27/20 : Investigating the presence of flaws
• CPC Class Codes: Y02T 50/40 : Weight reduction

Abstract

A system for monitoring electrical current passing through a cured bondline may include a current sensor network embedded in an adhesive layer of the cured bondline. The current sensor network may include a plurality of inductive coils and a plurality of current sensor nodes electrically interconnecting the inductive coils to form a plurality of current sensor loops generating induced current in response to a magnetic field associated with an electrical current passing through the adhesive layer. The current sensor nodes may generate current signals representative of the induced current. The current sensor network may include a digital data communications network located external to the cured bondline and receiving the current signals from the current sensor nodes and detecting and monitoring electrical current passing through the cured bondline based on the current signals.

Claims

1. A system for monitoring electrical current passing through a cured bondline of a bonded joint, the system comprising:

a current sensor network embedded in an adhesive layer of a cured bondline of a structural assembly, including;

a plurality of inductive coils; and

a plurality of current sensor nodes electrically interconnecting the inductive coils to form a plurality of current sensor loops generating induced current in response to a magnetic field associated with an electrical current passing through the adhesive layer, the current sensor nodes generating current signals representative of the induced current;

a digital data communications network located external to the cured bondline and receiving the current signals from the current sensor nodes and detecting and monitoring electrical current passing through the cured bondline based on the current signals.

2. The system of claim 1, wherein:

the adhesive layer comprises an epoxy adhesive, a polyurethane adhesive, and/or an acrylic adhesive.

3. The system of claim 1, wherein:

the structural assembly comprises a first structure formed of composite material, metallic material, or a combination thereof, bonded at the cured bondline to a second structure made of composite material, metallic material, or a combination thereof.

4. The system of claim 1, wherein:

the current sensor nodes are arranged such that the current sensor loops form a grid pattern in the cured bondline.

5. The system of claim 1, wherein:

at least some of the inductive coils are oriented generally orthogonally relative to one another such that at least one of the current sensor loops has a square shape defined by an inductive coil on each of four sides of the current sensor loop and having a current sensor node at each corner.

6. The system of claim 1, wherein:

the digital data communications network includes a data retrieval system and a data processing system;

the data retrieval system including one or more current integrators electrically connected to the current sensor nodes and integrating the induced current over time and generating one or more output signals; and

the data processing system determining a total electrical charge passing through the cured bondline based on the output signals.

7. The system of claim 1, wherein:

the inductive coils have an inductive coil height of no greater than approximately 0.020 inch, the inductive coil height being less than a bondline thickness of the cured bondline.

8. The system of claim 1, wherein:

the inductive coils have a flattened cross-sectional shape and an inductive coil height that is less than an inductive coil width.

9. The system of claim 8, wherein:

the flattened cross-sectional shape is a rectangular cross-sectional shape or an oval cross-sectional shape when the inductive coil is viewed from an end along a lengthwise direction of the inductive coil.

10. An aircraft, comprising:

a structural assembly including at least one bonded joint having an adhesive layer in a cured bondline bonding a first structure to a second structure;

a current sensor network embedded in an adhesive layer of the cured bondline, including;

a plurality of inductive coils generating induced current in response to a magnetic field associated with an electrical current passing through the adhesive layer; and

a plurality of current sensor nodes electrically interconnecting the inductive coils to form a plurality of current sensor loops, the current sensor nodes generating current signals representative of the induced current; and

a digital data communications network located external to the cured bondline and receiving the current signals from the current sensor network and detecting and monitoring electrical current passing through the cured bondline based on the current signals.

11. A method for monitoring electrical current passing through a cured bondline, comprising:

passing an electrical current through an adhesive layer of a cured bondline of a structural assembly, the electrical current having a magnetic field associated therewith, the adhesive layer containing a current sensor network including a plurality of inductive coils electrically interconnected at a plurality of current sensor nodes and forming a plurality of current sensor loops;

inducing an induced current in the current sensor loops in response to the magnetic field;

generating, at the current sensor nodes, current signals representative of the induced current;

transmitting the current signals to a digital data communications network located external to the cured bondline;

detecting and monitoring the electrical current using the digital data communications network based on the current signals.

12. The method of claim 11, wherein the step of detecting and monitoring the electrical current includes:

determining a relative magnitude of the electrical current passing through the adhesive layer based upon the current signals at the current sensor nodes; and

determining a distribution of the electrical current passing through the adhesive layer based upon the relative magnitude of the current signals.

13. The method of claim 11, wherein:

the electrical current is a result of a lightning strike on an aircraft containing the structural assembly.

14. The method of claim 11, wherein the steps of transmitting the current signals and detecting and monitoring the electrical current include:

transmitting the current signals from the current sensor nodes to one or more current integrators;

integrating, using the current integrators, the induced current over time to form output signals representative of the current signals; and

determining a total electrical charge passing through the cured bondline based on the output signals.

15. The method of claim 11, wherein the step of monitoring the electrical current include:

determining an electrical current profile of the electrical current passing through the adhesive layer.

16. The method of claim 11, wherein:

the adhesive layer comprises an epoxy adhesive, a polyurethane adhesive, and/or an acrylic adhesive.

17. The method of claim 11, wherein:

the structural assembly comprises a first structure formed of composite material, metallic material, or a combination thereof, bonded at the cured bondline to a second structure made of composite material, metallic material, or a combination thereof.

18. The method of claim 11, wherein:

the current sensor nodes are arranged such that the current sensor loops form a grid pattern in the cured bondline.

19. The method of claim 11, wherein:

the inductive coils have an inductive coil height of no greater than approximately 0.020 inch, the inductive coil height being less than a bondline thickness of the cured bondline.

20. The method of claim 11, wherein:

the inductive coils have a flattened cross-sectional shape such that an inductive coil height is less than an inductive coil width.