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2017-04-18
13/966,172
2013-08-13
US 9,625,361 B1
2017-04-18
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John H Le
Sheridan Ross P.C.
2035-06-26
Smart Summary: Real-time measurement systems can help detect when fiber-reinforced composite materials start to develop microfractures due to compression. These microfractures can lead to serious failures in aircraft components made from these materials. To prevent this, surfaces of the materials can be coated to stop fluids and gases from entering the fractures. This coating reduces the chances of failure in the composite materials. Overall, these methods aim to enhance the safety and reliability of aircraft parts. đ TL;DR
Methods and apparatus are described to use real-time measurement systems to detect the onset of compression induced micro-fracturing of fiber-reinforced composite materials. Measurements are described to detect the onset of compression induced micro-fracturing of fiber-reinforced composite materials to prevent catastrophic failures of aircraft components containing such materials. Methods and apparatus are described to prevent fluids and gases from invading any compression induced microfractures by coating surfaces of fiber-reinforced materials to reduce the probability of failure of such fiber-reinforced materials.
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G01N3/08 » CPC main
Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
B64C1/26 » CPC further
Fuselages; Constructional features common to fuselages, wings, stabilising surfaces and the like Attaching the wing or tail units or stabilising surfaces
B64C2001/0072 » CPC further
Fuselages; Constructional features common to fuselages, wings, stabilising surfaces and the like; Fuselage structures substantially made from particular materials from composite materials
Y10T428/1369 » CPC further
Stock material or miscellaneous articles; Hollow or container type article [e.g., tube, vase, etc.]; Polymer or resin containing [i.e., natural or synthetic] Fiber or fibers wound around each other or into a self-sustaining shape [e.g., yarn, braid, fibers shaped around a core, etc.]
G01N15/08 IPC
Investigating characteristics of particles; Investigating permeability, pore-volume, or surface-area of porous materials Investigating permeability, pore-volume, or surface area of porous materials
G01L1/00 IPC
Measuring force or stress, in general
B64C1/00 IPC
Fuselages; Constructional features common to fuselages, wings, stabilising surfaces and the like
B64C1/00 IPC
Aircraft structures or fairings
Applicant claims priority for this application to U.S. Provisional Patent Application Ser. No. 61/849,968, filed on Feb. 6, 2013, that is entitled âAdditional Methods and Apparatus to Prevent Failures of Fiber-Reinforced Composite Materials Under Compressive Stresses Caused by Fluids and Gases Invading Microfractures in Materialsâ, an entire copy of which is incorporated herein by reference. (PPA-34)
Applicant claims priority for this application to U.S. Provisional Patent Application Ser. No. 61/849,585, filed on Jan. 29, 2013, that is entitled âProposed Modifications of Main and APU Lithium-Ion Battery Assemblies on the Boeing 787 to Prevent Fires: Add One Cell, Eliminate Groundloops, and Monitor Each Cell with Optically Isolated Electronicsâ, an entire copy of which is incorporated herein by reference. (PPA-101)
Applicant claims priority for this application to U.S. Provisional Patent Application Ser. No. 61/850,095, filed on Feb. 9, 2013, that is entitled âProposed Modifications of Main and APU Lithium-Ion Battery Assemblies on the Boeing 787 to Prevent Fires: Add One Cell, Eliminate Groundloops, and Monitor Each Cell with Optically Isolated ElectronicsâPart 2â, an entire copy of which is incorporated herein by reference. (PPA-102)
Applicant also claims priority for this application to U.S. Provisional Patent Application Ser. No. 61/850,774, filed on Feb. 22, 2013, that is entitled âProposed Modifications of Main and APU Lithium-Ion Battery Assemblies on the Boeing 787 to Prevent Fires: Add One Cell, Eliminate Groundloops, and Monitor Each Cell with Optically Isolated ElectronicsâPart 3â, an entire copy of which is incorporated herein by reference. (PPA-103)
The present application is a continuation-in-part (C.I.P) application of co-pending U.S. patent application Ser. No. 12/804,039, filed on Jul. 12, 2010, that is entitled âMethods and Apparatus to Prevent Failures of Fiber-Reinforced Composite Materials Under Compressive Stresses Caused by Fluids and Gases Invading Microfractures in the Materialsâ, an entire copy of which is incorporated herein by reference. Applicant claims priority to this co-pending U.S. patent application Ser. No. 12/804,039 filed on Jul. 12, 2010. (Composite-1)
Co-pending U.S. patent application Ser. No. 12/804,039 claimed priority to U.S. Provisional Patent Application No. 61/270,709, filed Jul. 10, 2009, that is entitled âMethods and Apparatus to Prevent Failures of Fiber-Reinforced Composite Materials Under Compressive Stresses Caused by Fluids and Gases Invading Microfractures in the Materialsâ, an entire copy of which is incorporated herein by reference. Applicant claims priority to this U.S. Provisional Patent Application No. 61/270,709, filed Jul. 10, 2009. (PPA-32)
Co-pending U.S. patent application Ser. No. 12/804,039 claimed priority to U.S. Provisional Patent Application No. 61/396,518, filed on May 29, 2010, that is entitled âLetter to Boeing Managementâ, an entire copy of which is incorporated herein by reference. Applicant claims priority to this U.S. Provisional Patent Application No. 61/396,518, filed May 29, 2010. (PPA-33)
Co-pending U.S. patent application Ser. No. 12/804,039 is a continuation-in-part (C.I.P.) application of U.S. patent application Ser. No. 12/583,240, filed on Aug. 17, 2009, that is entitled âHigh Power Umbilicals for Subterranean Electric Drilling Machines and Remotely Operated Vehiclesâ, an entire copy of which is incorporated herein by reference. Ser. No. 12/583,240 was published on Dec. 17, 2009 having Publication Number US 2009/0308656 A1, an entire copy of which is incorporated herein by reference. Ser. No. 12/583,240 issued as U.S. Pat. No. 8,353,348 B2 on Jan. 15, 2013, an entire copy of which is incorporated herein by reference. Applicant claims priority to this U.S. Patent Application Ser. No. 12/583,240. (Rig-5)
Ser. No. 12/583,240 is a continuation-in-part (C.I.P.) application of U.S. patent application Ser. No. 12/005,105, filed on Dec. 22, 2007, that is entitled âHigh Power Umbilicals for Electric Flowline Immersion Heating of Produced Hydrocarbonsâ, an entire copy of which is incorporated herein by reference. Ser. No. 12/005,105 was published on Jun. 26, 2008 having Publication Number US 2008/0149343 A1, an entire copy of which is incorporated herein by reference. Ser. No. 12/005,105 is now abandoned. Applicant claims priority to this U.S. patent application Ser. No. 12/005,105. (Rig-4)
Ser. No. 12/005,105 a continuation-in-part (C.I.P.) application of U.S. patent application Ser. No. 10/800,443, filed on Mar. 14, 2004, that is entitled âSubstantially Neutrally Buoyant and Positively Buoyant Electrically Heated Flowlines for Production of Subsea Hydrocarbonsâ, an entire copy of which is incorporated herein by reference. Ser. No. 10/800,443 was published on Dec. 9, 2004 having Publication Number US 2004/0244982 A1, an entire copy of which is incorporated herein by reference. Ser. No. 10/800,443 issued as U.S. Pat. No. 7,311,151 B2 on Dec. 25, 2007. Applicant claims priority to this U.S. patent application Ser. No. 10/800,443. (Rig-3)
Ser. No. 10/800,443 claimed priority from U.S. Provisional Patent Applications No. 60/455,657, No. 60/504,359, No. 60/523,894, No. 60/532,023, and No. 60/535,395. Applicant claims priority in the present application to these five Provisional Patent Applications, and an entire copy of each is incorporated herein by reference.
Ser. No. 10/800,443 is a continuation-in-part (C.I.P.) application of U.S. patent application Ser. No. 10/729,509, filed on Dec. 4, 2003, that is entitled âHigh Power Umbilicals for Electric Flowline Immersion Heating of Produced Hydrocarbonsâ, an entire copy of which is incorporated herein by reference. Ser. No. 10/729,509 was published on Jul. 15, 2004 having the Publication Number US 2004/0134662 A1, an entire copy of which is incorporated herein by reference. Ser. No. 10/729,509 issued as U.S. Pat. No. 7,032,658 B2 on Apr. 25, 2006, an entire copy of which is incorporated herein by reference. Applicant claims priority to this U.S. patent application Ser. No. 10/729,509. (Rig-2)
Ser. No. 10/729,509 claimed priority from various Provisional Patent Applications, including Provisional Patent Application Nos. 60/432,045, 60/523,894, 60/504359, 60/455,657 and 60/448,191. Applicant claims priority in the present application to these five Provisional Patent Applications, and an entire copy of each is incorporated herein by reference.
Ser. No. 10/729,509 is a continuation-in-part (C.I.P) application of U.S. patent application Ser. No. 10/223,025, filed Aug. 15, 2002, that is entitled âHigh Power Umbilicals for Subterranean Electric Drilling Machines and Remotely Operated Vehiclesâ, an entire copy of which is incorporated herein by reference. Ser. No. 10/223,025 was published on Feb. 20, 2003, having Publication Number US 2003/0034177 A1, an entire copy of which is incorporated herein by reference. Ser. No. 10/223,025 issued as U.S. Pat. No. 6,857,486 B2 on Feb. 22, 2005, an entire copy of which is incorporated herein by reference. Applicant claims priority to this U.S. patent application Ser. No. 10/223,025. (Rig-1)
Co-pending U.S. patent application Ser. No. 13/694,884, filed on Jan. 15, 2013, is a continuation-in-part (C.I.P.) application of U.S. patent application Ser. No. 12/583,240, filed on Aug. 17, 2009, that is entitled âHigh Power Umbilicals for Subterranean Electric Drilling Machines and Remotely Operated Vehiclesâ, an entire copy of which is incorporated herein by reference. Applicant does not claim priority to this co-pending U.S. patent application Ser. No. 13/694,884, filed on Jan. 15, 2013. (Rig-7)
This application relates to Provisional Patent Application No. 60/313,654 filed on Aug. 19, 2001, that is entitled âSmart Shuttle Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/353,457 filed on Jan. 31, 2002, that is entitled âAdditional Smart Shuttle Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/367,638 filed on Mar. 26, 2002, that is entitled âSmart Shuttle Systems and Drilling Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/384,964 filed on Jun. 3, 2002, that is entitled âUmbilicals for Well Conveyance Systems and Additional Smart Shuttles and Related Drilling Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/432,045, filed on Dec. 8, 2002, that is entitled âPump Down Cement Float Valves for Casing Drilling, Pump Down Electrical Umbilicals, and Subterranean Electric Drilling Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/448,191, filed on Feb. 18, 2003, that is entitled âLong Immersion Heater Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/455,657, filed on Mar. 18, 2003, that is entitled âFour SDCI Application Notes Concerning Subsea Umbilicals and Construction Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/504,359, filed on Sep. 20, 2003, that is entitled âAdditional Disclosure on Long Immersion Heater Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/523,894, filed on Nov. 20, 2003, that is entitled âMore Disclosure on Long Immersion Heater Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/532,023, filed on Dec. 22, 2003, that is entitled âNeutrally Buoyant Flowlines for Subsea Oil and Gas Productionâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/535,395, filed on Jan. 10, 2004, that is entitled âAdditional Disclosure on Smart Shuttles and Subterranean Electric Drilling Machinesâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/661,972, filed on Mar. 14, 2005, that is entitled âElectrically Heated Pumping Systems Disposed in Cased Wells, in Risers, and in Flowlines for Immersion Heating of Produced Hydrocarbonsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/665,689, filed on Mar. 28, 2005, that is entitled âAutomated Monitoring and Control of Electrically Heated Pumping Systems Disposed in Cased Wells, in Risers, and in Flowlines for Immersion Heating of Produced Hydrocarbonsâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/669,940, filed on Apr. 9, 2005, that is entitled âMethods and Apparatus to Enhance Performance of Smart Shuttles and Well Locomotivesâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/761,183, filed on Jan. 23, 2006, that is entitled âMethods and Apparatus to Pump Wirelines into Cased Wells Which Cause No Reverse Flowâ, an entire copy of which is incorporated herein by reference.
This application relates to Provisional Patent Application No. 60/794,647, filed on Apr. 24, 2006, that is entitled âDownhole DC to AC Converters to Power Downhole AC Electric Motors and Other Methods to Send Power Downholeâ, an entire copy of which is incorporated herein by reference.
The following applications are related to this application, but applicant does not claim priority from the following related applications.
This application relates to Ser. No. 09/375,479, filed Aug. 16, 1999, having the title of âSmart Shuttles to Complete Oil and Gas Wellsâ, that issued on Feb. 20, 2001, as U.S. Pat. No. 6,189,621 B1, an entire copy of which is incorporated herein by reference.
This application relates to Ser. No. 09/487,197, filed Jan. 19, 2000, having the title of âClosed-Loop System to Complete Oil and Gas Wellsâ, that issued on Jun. 4, 2002 as U.S. Pat. No. 6,397,946 B1, an entire copy of which is incorporated herein by reference.
This application relates to application Ser. No. 10/162,302, filed Jun. 4, 2002, having the title of âClosed-Loop Conveyance Systems for Well Servicingâ, that issued as U.S. Pat. No. 6,868,906 B1 on Mar. 22, 2005, an entire copy of which is incorporated herein by reference.
This application relates to application Ser. No. 11/491,408, filed Jul. 22, 2006, having the title of âMethods and Apparatus to Convey Electrical Pumping Systems into Wellbores to Complete Oil and Gas Wellsâ, that issued as U.S. Pat. No. 7,325,606 B1 on Feb. 5, 2008, an entire copy of which is incorporated herein by reference.
This application relates to application Ser. No. 12/012,822, filed Feb. 5, 2008, having the title of âMethods and Apparatus to Convey Electrical Pumping Systems into Wellbores to Complete Oil and Gas Wellsâ, that issued as U.S. Pat. No. 7,836,950 B2 on Nov. 23, 2010, an entire copy of which is incorporated herein by reference.
This application also relates to PCT Application Serial Number PCT/US00/22095, filed Aug. 9, 2000, having the title of âSmart Shuttles to Complete Oil and Gas Wellsâ, that has International Publication Number WO 01/12946 A1, that has International Publication Date of Feb. 22, 2001, that issued as European Patent No. 1,210,498 B1 on Nov. 28, 2007, an entire copy of which is incorporated herein by reference.
This application relates to PCT Patent Application Number PCT/US02/26066 filed on Aug. 16, 2002, entitled âHigh Power Umbilicals for Subterranean Electric Drilling Machines and Remotely Operated Vehiclesâ, that has the International Publication Number WO 03/016671 A2, that has International Publication Date of Feb. 27, 2003, that issued as European Patent No. 1,436,482 B1 on Apr. 18, 2007, an entire copy of which is incorporated herein by reference.
This application relates to PCT Patent Application Number PCT/US03/38615 filed on Dec. 5, 2003, entitled âHigh Power Umbilicals for Electric Flowline Immersion Heating of Produced Hydrocarbonsâ, that has the International Publication Number WO 2004/053935 A2, that has International Publication Date of Jun. 24, 2004, an entire copy of which is incorporated herein by reference.
This application relates to PCT Patent Application Number PCT/US2004/008292, filed on Mar. 17, 2004, entitled âSubstantially Neutrally Buoyant and Positively Buoyant Electrically Heated Flowlines for Production of Subsea hydrocarbonsâ, that has International Publication Number WO 2004/083595 A2 that has International Publication Date of Sep. 30, 2004, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 451,044, filed on Feb. 8, 1999, that is entitled âRE: âInvention DisclosureââDrill Bit Having Monitors and Controlled Actuatorsâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 458,978 filed on Jul. 13, 1999 that is entitled in part âRE: âINVENTION DISCLOSURE MAILED Jul. 13, 1999â, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 475,681 filed on Jun. 17, 2000 that is entitled in part âROV Conveyed Smart Shuttle System Deployed by Workover Ship for Subsea Well Completion and Subsea Well Servicingâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 496,050 filed on Jun. 25, 2001 that is entitled in part âSDCI Drilling and Completion Patents and Technology and SDCI Subsea Re-Entry Patents and Technologyâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 480,550 filed on Oct. 2, 2000 that is entitled in part âNew Draft Figures for New Patent Applicationsâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 493,141 filed on May 2, 2001 that is entitled in part âCasing Boring Machine with Rotating Casing to Prevent Sticking Using a Rotary Rigâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 492,112 filed on Apr. 12, 2001 that is entitled in part âSmart Shuttleâą Conveyed Drilling Systemsâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 495,112 filed on Jun. 11, 2001 that is entitled in part âLiner/Drainhole Drilling Machineâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 494,374 filed on May 26, 2001 that is entitled in part âContinuous Casting Boring Machineâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 495,111 filed on Jun. 11, 2001 that is entitled in part âSynchronous Motor Injector Systemâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 497,719 filed on Jul. 27, 2001 that is entitled in part âMany Uses for The Smart Shuttleâą and Well Locomotiveâąâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 498,720 filed on Aug. 17, 2001 that is entitled in part âElectric Motor Powered Rock Drill Bit Having Inner and Outer Counter-Rotating Cutters and Having Expandable/Retractable Outer Cutters to Drill Boreholes into Geological Formationsâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 499,136 filed on Aug. 26, 2001, that is entitled in part âCommercial System Specification PCP-ESP Power Section for Cased Hole Internal Conveyance Large Well Locomotiveâąâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 516,982 filed on Aug. 20, 2002, that is entitled âFeedback Control of RPM and Voltage of Surface Supplyâ, an entire copy of which is incorporated herein by reference.
This application relates to disclosure in U.S. Disclosure Document No. 531,687 filed May 18, 2003, that is entitled âSpecific Embodiments of Several SDCI Inventionsâ, an entire copy of which is incorporated herein by reference.
This application relates to U.S. Disclosure Document No. 572,723, filed on Mar. 14, 2005, that is entitled âElectrically Heated Pumping Systems Disposed in Cased Wells, in Risers, and in Flowlines for Immersion Heating of Produced Hydrocarbonsâ, an entire copy of which is incorporated herein by reference.
This application relates to U.S. Disclosure Document No. 573,813, filed on Mar. 28, 2005, that is entitled âAutomated Monitoring and Control of Electrically Heated Pumping Systems Disposed in Cased Wells, in Risers, and in Flowlines for Immersion Heating of Produced Hydrocarbonsâ, an entire copy of which is incorporated herein by reference.
This application relates to U.S. Disclosure Document No. 574,647, filed on Apr. 9, 2005, that is entitled âMethods and Apparatus to Enhance Performance of Smart Shuttles and Well Locomotivesâ, an entire copy of which is incorporated herein by reference.
This application relates to U.S. Disclosure Document No. 593,724, filed Jan. 23, 2006, that is entitled âMethods and Apparatus to Pump Wirelines into Cased Wells Which Cause No Reverse Flowâ, an entire copy of which is incorporated herein by reference.
This application relates to U.S. Disclosure Document No. 595,322, filed Feb. 14, 2006, that is entitled âAdditional Methods and Apparatus to Pump Wirelines into Cased Wells Which Cause No Reverse Flowâ, an entire copy of which is incorporated herein by reference.
This application relates to U.S. Disclosure Document No. 599,602, filed on Apr. 24, 2006, that is entitled âDownhole DC to AC Converters to Power Downhole AC Electric Motors and Other Methods to Send Power Downholeâ, an entire copy of which is incorporated herein by reference.
This application relates to the U.S. Disclosure Document that is entitled âSeals for Smart Shuttlesâ that was mailed to the USPTO on the Date of Dec. 22, 2006 by U.S. Mail, Express Mail Service having Express Mail Number EO 928 739 065 US, an entire copy of which is incorporated herein by reference.
Various references are referred to in the above defined U.S. Disclosure Documents. For the purposes herein, the term âreference cited in applicant's U.S. Disclosure Documentsâ shall mean those particular references that have been explicitly listed and/or defined in any of applicant's above listed U.S. Disclosure Documents and/or in the attachments filed with those U.S. Disclosure Documents. Applicant explicitly includes herein by reference entire copies of each and every âreference cited in applicant's U.S. Disclosure Documentsâ. In particular, applicant includes herein by reference entire copies of each and every U.S. Patent cited in U.S. Disclosure Document No. 452648, including all its attachments, that was filed on Mar. 5, 1999. To best knowledge of applicant, all copies of U.S. Patents that were ordered from commercial sources that were specified in the U.S. Disclosure Documents are in the possession of applicant at the time of the filing of the application herein.
Applications for U.S. Trademarks have been filed in the USPTO for several terms used in this application. An application for the Trademark âSmart Shuttleâąâ was filed on Feb. 14, 2001 that is Ser. No. 76/213,676, an entire copy of which is incorporated herein by reference. The term Smart ShuttleÂź is now a Registered Trademark. The âSmart Shuttleâą is also called the âWell Locomotiveâą â. An application for the Trademark âWell Locomotiveâąâ was filed on Feb. 20, 2001 that is Ser. No. 76/218,211, an entire copy of which is incorporated herein by reference. The term Well LocomotiveÂź is now a Registered Trademark. An application for the Trademark of âDownhole Rigâąâ was filed on Jun. 11, 2001 that is Ser. No. 76/274,726, an entire copy of which is incorporated herein by reference. An application for the Trademark âUniversal Completion Deviceâąâ was filed on Jul. 24, 2001 that is Ser. No. 76/293,175, an entire copy of which is incorporated herein by reference. An application for the Trademark âDownhole BOPâąâ was filed on Aug. 17, 2001 that is Ser. No. 76/305,201, an entire copy of which is incorporated herein by reference.
Accordingly, in view of the Trademark registrations and applications, the term âsmart shuttleâ is capitalized as âSmart Shuttleâ; the term âwell locomotiveâ is capitalized as âWell Locomotiveâ; the term âdownhole rigâ is capitalized as âDownhole Rigâ; the term âuniversal completion deviceâ is capitalized as âUniversal Completion Deviceâ; and the term âdownhole bopâ is capitalized as âDownhole BOPâ.
In addition, the following Trademarks are also used herein: âSubterranean Electric Drilling Machineâąâ abbreviated âSEDMâą.
Field of the Invention
The field of invention relates to methods and apparatus to prevent failures of fiber-reinforced composite materials under compressive stresses caused by fluids and gases invading microfractures in those materials.
Description of the Related Art
Catastrophic failures of fiber-reinforced composite materials have proven to be a problem in the oil and gas industries. Now, such fiber-reinforced composite materials have now been incorporated into critically important structural components of aircraft. Such structural components include but are not limited to the wing and the wing junction boxes of aircraft. Any catastrophic failure of fiber-reinforced wings and/or wing junction boxes or other structural components during flight would likely result in significant loss of life and the destruction of the aircraft.
A problem with composites is that they catastrophically delaminate under certain circumstances. For example please refer to the article entitled âOffshore oil composites: Designing in cost savingsâ by Dr. Jerry Williams, a copy of which appears in Attachment No. 3 to U.S. Provisional Patent Application No. 61/270,709, filed on Jul. 10, 2009, an entire copy of which is incorporated herein by reference. One notable quote is as follows: â . . . (the) failure modes are different for metals and composites: Compression failure modes for composites include delamination and shear crippling that involves microbuckling of the fibers.â
Based upon Dr. Williams' assessments, clearly compressive forces applied to composites can cause significant problems. Carbon fiber filaments are typically woven into a fabric material, which may be typically impregnated with epoxy resin. Such structures are then typically laminated and cured. On a microscopic level, and in compression, the carbon fibers can buckle. This in turn opens up what the applicant herein calls âmicrofracturesâ (or âmicrocracksâ) in larger fabricated parts which are consequently subject to invasion by fluids and gasses.
Because of the risk of catastrophic delamination of composites under compression, our firm, Smart Drilling and Completion, Inc., decided some time ago to use titanium or aluminum interior strength elements, and to surround these materials with fiber-reinforced composite materials to make certain varieties of umbilicals. For example, please see FIGS. 1A, 1B, and 1C in the U.S. Patent Application entitled âHigh Power Umbilicals for Subterranean Electric Drilling Machines and Remotely Operated Vehiclesâ, that is Ser. No. 12/583,240, filed Aug. 17, 2009, that was published on Dec. 17, 2009 as US 2009/038656 A1, an entire copy of which is incorporated herein by reference. Perhaps our firm will also include embedded syntactic foam materials so that the fabricated umbilicals are neutrally buoyant in typical drilling muds for its intended use in a borehole.
Reference is made to the front-page article in The Seattle Times dated Jun. 25, 2009 entitled â787 delay: months, not weeksâ, an entire copy of which is incorporated herein by reference. This article states in part, under the title of âLast months: testâ the following: âThis test produced delamination of the composite materialâseparation of the carbon-fiber layers, in small areas where the MHI wings join the structure box embedded in the center fuselage made by Fugi Heavy Industries (FHI) of Japan.â It should certainly be no news to those of at least ordinary skill in the art that this is a high stress area, and portions of these stresses will inevitably be compressive in nature.
Consequently, in such areas subject to compressive stresses, microfractures will allow, for example, water, water vapor, fuel, grease, fuel vapor, and vapors from burned jet fuel to enter these microfractures, that in turn, could cause a catastrophic failure of the wing and/or the wing junction boxâpossibly during flight. Similar catastrophic problems could arise at other locations including composite materials.
The counter-argument can be presented as follows: âbut, the military flies aircraft made from these materials all the time, and there is no problemâ. Yes, but, the military often keeps their planes in hangers, has many flight engineers regularly and continuously inspecting them, and suitably recoats necessary surfaces with many chemicals to protect the composites and to patch radar absorbing stealth materials. So, it may not be wise to extrapolate the âno problems in the military argumentâ to the exposure of wings and wing boxes in civil commercial aircraft, including those of the 787, to at least some substantial repetitive compressive forces that may also be simultaneously subject to long-term environmental contamination by ambient fluids and gases.
Reference is also made to the Jun. 24, 2009 summary article in the Daily Finance entitled âIs Boeing's 787 safe to flyâ?, by Peter Cohan, the one page summary copy of which appears in Attachment No. 4 to U.S. Provisional Patent Application No. 61/270,709 filed on Jul. 10, 2009, an entire copy of which is incorporated herein by reference. This article states in part: âComposites are lighter and stronger hence able to fly more fuel efficiently. But engineers don't completely understand how aircraft made of composite materials will respond to the stresses of actual flight. This incomplete understanding is reflected in the computer models they use to design the aircraft. The reason for the fifth delay is that the actual 787 did not behave the way the model predicted.â
The complete article entitled âIs Boeing's 787 safe to fly?â, in the Daily Finance, by Peter Cohan, dated Jun. 24, 2009, an entire copy of which is incorporated herein by reference, further states: âSpecifically, Boeing found that portions of the airframeâthose where the top of the wings join the fuselageâexperienced greater strain than computer models had predicted. Boeing could take months to fix the 787 design, run more ground tests and adjust computer models to better reflect reality.â This article continues: âAnd this is what raises questions about the 787's safety. If engineers continue to be surprised by the 787's response to real-world operating stresses, there is some possibility that the testing process might not catch all the potential problems with the design and construction of the aircraft.â
Significant problems have occurred in the past during the development of new airframes. For example, inadequate attention was paid the possibility of high stresses causing catastrophic metal fatigue during the development of the de Havilland Comet. High stresses were a surprise particularly around the square window corners. Such failure of adequate attention resulted in several notable crashes.
Another example is the explosive decompression in flight suffered by Aloha Airlines Flight 243. Water entering into an epoxy-aluminum bonded area caused the basic problem. Consequently, an epoxy resin failure between two laminated materials (in this case aluminum) has caused significant problems in the past.
An object of the invention is to provide methods and apparatus to use real-time measurement systems to detect the onset of compression induced micro-fracturing of fiber-reinforced composite materials.
Another object of the invention is to provide measurement means to detect the onset of compression induced micro-fracturing of fiber-reinforced composite materials to prevent catastrophic failures of aircraft components containing such materials.
Yet another object of the invention is to provide methods and apparatus to prevent fluids and gases from invading any compression induced microfractures through any coated surfaces of fiber-reinforced materials to reduce the probability of failure of such fiber-reinforced materials.
Another object of the invention is to provide a real time electronics system measurement means fabricated within a portion of an aircraft made of fiber-reinforced composite materials to detect the onset of compression induced micro-fracturing of the fiber-reinforced composite materials to prevent the catastrophic failure of the portion of the aircraft or portions of the aircraft proximate thereto.
Yet another object of the invention is to provide a real time electronics system measurement means to measure the differential resistivity of materials fabricated within a portion of an aircraft made of fiber-reinforced composite materials to detect the onset of compression induced micro-fracturing of the fiber-reinforced composite materials to prevent the catastrophic failure of the portion of the aircraft.
FIG. 1 shows an aircraft having substantial fiber-reinforced materials, such as a Boeing 787.
FIG. 2 shows an embodiment of how the right and left wings are attached to the center wing box, and an embodiment of the distribution of sensor array systems in a portion of the fiber-reinforced composite materials particularly subject to compressive stresses.
FIG. 3 shows the upper right wing connection apparatus of the embodiment of FIG. 2 which connects the upper right wing to the mating portion of the upper right center wing box.
FIG. 4 shows modifications to the upper right wing connection apparatus of the embodiment of FIG. 2 which connects the upper right wing to the mating portion of the upper center wing box.
FIG. 5 shows one embodiment of a real time electronics system measurement means fabricated within a portion of an aircraft made of fiber-reinforced composite materials to detect the onset of compression induced micro-fracturing.
FIG. 6 shows one embodiment of a real time electronics system measurement means particularly suited for a laboratory demonstration of the measurement principles applied in the embodiment shown in FIG. 5.
The fiber-reinforced wings and wing boxes of Boeing 787's are described very well in an article in The Seattle Times, dated Jul. 30, 2009, entitled âDouble trouble for Boeing 787 wingâ by Dominic Gates, that appears on the front page and on A8, an entire copy of which is incorporated herein by reference. That article provided several colored drawings showing the then existing wings and wing box assemblies, and the then proposed reinforcement of those assemblies.
Some aspects of FIGS. 1, 2, 3 and 4 herein are based on the information provided in that Jul. 30, 2009 article in The Seattle Times. Applicant is grateful for that information.
FIG. 1 shows an airplane 2 having substantial quantities of fiber-reinforced composite materials, that has a right wing 4 (when viewed standing in front of airplane 2), left wing 6, and center wing box 8. The wings and wing boxes are substantially fabricated from fiber-reinforced materials. In the Jul. 30, 2009 article, the airplane sketched was the Boeing 787. It should be appreciated that the inventions disclosed herein are not limited to the Boeing 787 nor to wings and wing boxes, but are applicable to any structure comprising fiber-reinforced materials.
FIG. 2 shows a cross section view of the center wing box 8 in fuselage 10, having its top skin 12 and bottom skin 14, its top stringers 16, and its bottom stringers 18. Wing 6 has its top wing skin 20, bottom wing skin 22, its top stringers 24, and its bottom stringers 26. Wing 4 has its top wing skin 28, its bottom wing skin 30, its top stringers 32, and bottom stringers 34. Left wing connection apparatus 36 connects the left wing 6 to the mating portion of the center wing box. Upper right wing connection apparatus 38 connects the right wing 4 to the mating portion of the center wing box.
FIG. 3 shows an expanded version of the upper right wing connection apparatus 38. Many of the various elements have already been identified above. In addition, the right-hand wall of the fuselage 40 is coupled to the center wing box 8 and to the right wing 4 by parts 42, 44, and 46. High stress points 48 and 50 were identified as being related to the failures of the wings and the center wing junction box during the tests described in the article dated Jul. 30, 2010.
In FIG. 4, the modifications described in the article dated Jul. 30, 2010 are shown. U-shaped cutouts in the stringers 52 and 54 are shown, along with the addition of fastener bolts 56 and 58. Element 38A shows an expanded version of the upper right wing connection apparatus that has been modified.
Referring again to FIG. 2, lower left-wing connection apparatus 100 and lower right-wing connection apparatus 102 are areas which are in substantial compression. So, in these areas, the fiber-reinforced materials are in substantial compression. Consequently, sensor array systems 104, 106, 108, and 110 are shown as being placed in areas subject to substantial compressive forces applied to the fiber-reinforced composite materials. These sensor array systems are monitored to determine if microfractures are being produced, and to determine if fluids and gases are invading any such microfractures in the materials.
Information from the sensor arrays are sent via wires such as 112 through wing box to fuselage connector 114 to monitoring instrumentation 116. That monitoring instrumentation may be in the fuselage, or external to the fuselage, or may be connected by a wireless communications link. Power to any measurement devices in the sensor array systems are provided by wires such as 112. By âsensor arrayâ is meant to include means to make a change to the materials (such as the conduction of electricity) and the measurement of a parameter (such as a change in resistance or resistivity of the materials).
To avoid fluid invasion problems, in several preferred embodiments, real-time measurement systems are described to detect the onset of compression induced micro-fracturing. So, not only would stress and strain be measured in live-time, but also whether or not fluids and gases have invaded the microfractures. In other preferred embodiments, the electrical resistivity between adjacent laminated sections is used as a convenient way to determine if there has been invasion of conductive fluids (such as salt water) into the microfractures. Extraordinarily precise differential measurements may be made of such resistivity, and the applicant has had many years of experience in such measurements during the development of the Through Casing Resistivity Tool. In other preferred embodiments, precise differential measurements are made in real-time of various dielectric properties that will allow the detection of non-conductive fluids and gases. In other embodiments, undue swelling of the composites are also directly measured with sensors that will give an advance indication of potential catastrophic failures due to fluid and/or gas invasion. In many embodiments, the sensors themselves are integrated directly into the composite materials during manufacture. In some embodiments, the existing carbon fibers already present may be used. Accordingly, there are many live-time measurements that we can use to prevent catastrophic failures.
Yet other embodiments of the invention provide inspection techniques based on measurements to determine invasion of fluids and gases into the composite materials is clearly needed.
A preferred embodiment of the invention describes a method to use real-time measurement systems to detect the onset of compression induced micro-fracturing of fiber-reinforced composite materials. In a preferred embodiment, the real-time measurement systems measure the electrical resistivity between different portions of the fiber-reinforced composite materials.
In selected embodiments, changes in time of electrical resistivity between different portions of the fiber-reinforced composite materials are used to determine the invasion of conductive fluids into the microfractures of the fiber-reinforced composite materials. In several preferred embodiments, fiber-reinforced composite materials comprise a portion of an umbilical in a subterranean wellbore that conducts electricity through insulated wires to an electric drilling machine. In other preferred embodiments, the fiber-reinforced composite materials comprise a portion of a Boeing 787 wing, 787 wing box assembly, and any combination thereof. The invention applies to fiber-reinforced composite materials used in any portion of an airplane.
In other preferred embodiments, the real-time measurement systems measure dielectric properties between different portions of fiber-reinforced composite materials.
In selected embodiments, changes in time of measured dielectric properties between different portions of the fiber-reinforced composite materials are used to determine the invasion of fluids and gases into the microfractures of said fiber-reinforced composite materials. In selected preferred embodiments, these methods are used to monitor fiber-reinforced composite materials that comprise a portion of an umbilical in a subterranean wellbore. In other selected embodiments, the methods and apparatus are used to monitor fiber-reinforced composite materials comprise a portion of a Boeing 787 wing, 787 wing box assembly, and any combination thereof, or any other portion of fiber-reinforced composite materials comprising any portion of an airplane.
Selected preferred embodiments of the invention provide methods and apparatus wherein substantial portions of the real-time measurement systems are fabricated within the fiber-reinforced composite materials. In selected preferred embodiments, changes in time of measured properties are used to determine the invasion of fluids and gases into the microfractures of the fiber-reinforced composite materials.
In selected embodiments, measurement means are provided to detect the onset of compression induced micro-fracturing of fiber-reinforced composite materials to prevent catastrophic failures of aircraft components containing such materials.
In other preferred embodiments, the measurement means further includes means to detect and measure the volume of fluids and gases that have invaded the microfractures in the fiber-reinforced composite materials.
In yet another preferred embodiment, methods and apparatus are provided to prevent fluids and gases from invading any compression induced microfractures of fiber-reinforced materials to reduce the probability of failure of such materials. Such methods and apparatus include special coating materials that coat fabricated fiber-reinforced materials, wherein such special materials are defined to be a coating material means. Such methods and apparatus further includes a coating material means is used to coat fiber-reinforced composite materials in visually inaccessible areas of airplanes. Such methods and apparatus further include special materials incorporated within the fiber-reinforced materials that are hydrophilic (tend to repel water). Such methods and apparatus further include special materials incorporated within the fiber-reinforced materials that absorb during a chemical reaction that produces a new portion of the matrix material in the fiber-reinforced composite material. Such methods and apparatus further includes special materials incorporated within the fiber-reinforced materials that absorb gases. Such methods and apparatus yet further includes self-healing substances designed to fill any such microfractures in the fiber-reinforced materials. Such methods and apparatus yet further include self-healing substances whereby at least one component of the matrix material used to make the fiber-reinforced composite material. Such matrix material may be comprised of at least an epoxy resin material and a hardener component. The self-healing substance may further include a hardener component designed to set-up slowly over a period in excess of one year.
Another preferred embodiment of the invention includes methods and apparatus wherein predetermined compressional stresses induce a chemical reaction within a special material fabricated within the fiber-reinforced composite material that prevents fluids and gases from invading any compression induced microfractures of fiber-reinforced materials to reduce the probability of failure of such materials. In several preferred embodiments, such predetermined compressional stresses induce a structural phase transition within a special material fabricated within the fiber-reinforced composite material that prevents fluids and gases from invading any compression induced microfractures of fiber-reinforced materials to reduce the probability of failure of such materials.
Further embodiments include methods and apparatus wherein at least a portion of the fiber-reinforced composite material is exposed to a relatively high-pressure inert gas which slowly diffuses through other portions of the fiber-reinforced composite material to prevent other fluids and gases from invading any compression induced microfractures of the fiber-reinforced material to reduce the probability of failure of the material. The inert gas can include dry nitrogen. Such methods and apparatus apply to any portion of a fiber-reinforced material that is comprised of at least one channel within said fiber-reinforce composite material.
Yet other preferred embodiments provide additional special fibers that are added during the manufacturing process of a standard fiber-reinforced composite material to make a new special fiber-reinforced material to prevent fluids and gases from invading any compression induced microfractures of said special fiber-reinforced material to reduce the probability of failure of said special fiber-reinforced material. Such special fibers include fibers comprised of titanium. Such special fibers include fibers comprised of any alloy containing titanium.
Other embodiments provide special fibers that are added during the manufacturing process of a standard fiber-reinforced composite material to make a new special fiber-reinforced material to reduce the probability of the formation of stress-induced microfractures in said material. Such special fibers include fibers comprised of titanium. Such special fibers include fibers comprised of any alloy containing titanium.
Other preferred embodiments provide methods and apparatus to isolate the wing boxes of composite aircraft from environmental liquids, such as water, and from environmental gases, such as jet exhaust to reduce the probability of failure of such materials. Such methods and apparatus include means to prevent fluids and gases from invading any compression induced microfractures through any coated surfaces of fiber-reinforced materials to reduce the probability of failure of such fiber-reinforced materials.
Other selected embodiments of the invention incorporate the relevant different types of physical measurements defined in U.S. Provisional Patent Application 61/270,709, filed Jul. 9, 2010, an entire copy of which is incorporated herein by reference. For example, such physical measurements include acoustic transmitters and receivers, ultrasonic transmitters and receivers, phased array ultrasonics, thermosonics, air coupled ultrasonics, acoustic resonance techniques, x-ray techniques, radiography, thermal wave imaging, thermography and shearography. These cited physical measurements, and selected additional physical measurements described in the References incorporated into this document, may be used to make the basic sensors of a real time electronics system measurement means fabricated within a portion of an aircraft made of fiber-reinforced composite materials to detect the onset of compression induced micro-fracturing of said fiber-reinforced composite materials to prevent the catastrophic failure of said portion of said aircraft.
Reference is made to the article entitled âNondestructive Inspection of Composite Structures: Methods and Practiceâ by David K. Hsu, 17th World Conference on Nondestructive Testing, 25-28 Oct. 2008, Shanghai, China, an entire copy of which is incorporated herein by reference. This is a review article of methods and apparatus to inspect composite materials and will be hereinafter abbreviated as Hsu, 2008.
Many non-destructive tests are reviewed, which include water- and air-coupled ultrasound bond testing, manual and automated tap testing, thermography, and shearography (hereinafter collectively, âstandard techniquesâ).
In the case of one of the mechanisms described herein, composite materials under compression in or near the wing box ingest or soak-up water, jet fuel, etc. and are subject to a catastrophic delimitation.
The interior portion of the wing box is very hard to access. Some portions subject to testing are deep into the wing, significant distances from the outer skin of the aircraft. The interior portion of the wing box is not subject to any external visual inspection from outside the aircraft. Nor will any of the âstandard techniquesâ noted above work to determine the failure mechanism described herein on an interior portion of the wing box from outside the aircraft.
An individual can access some areas of the interior portion of the wing box from inside the wing. There are crawl spaces. Some hand-held inspection tools, such as a hand-held tap tester, or hand-held acoustic device, could be used by an individual to inspect certain portions of the interior portion of the wing box. But, the sensitivity of these are severely limited.
In Section 4.3 of Hsu, 2008, the article talks about sensitivities . . . âas small as 3 mm (â âł) diameter can be detected . . . â. This is a pretty large hole and not sensitive enough to determine the presence or absence of microfractures of the type produced by the mechanism described herein.
In addition, reference is made to an article in USA Today, entitled âSigns of pre-existing fatigue found on Southwest aircraftâ, by Roger Yu, Apr. 4, 2011 (the âUSA Today Articleâ), an entire copy of which is incorporated herein by reference. The USA Today Article states in part:
The USA Today Article further states in part:
So, even after many years of flying, and after much study, the FAA concludes that they do not have a good way to determine what is going to happen on a given aircraft by using present inspection techniques. Please note the first above quote from the USA Today Article implies that cracks are to be expected. Furthermore, microcracks are apparently common in aluminumâwhich are, by analogy, just the type of microcracks in composites that can result in the failure mechanism described herein.
In the second above quote from the USA Today Article, microcracks may link up and grow very rapidly, a phenomenon which might be called âswarming of microcracksâ for the purposes herein. If such swarming occurs, and fluids such as water, jet fuel, etc. invade the structure, the composite can catastrophically fail within a short period of time. This is one mechanism described herein.
None of the âstandard techniquesâ noted above are adequate to monitor the failure mechanism described herein. However, resistivity measurements are cited herein as having the resolution to detect and monitor this problem.
Accordingly, another preferred embodiment of the invention is shown in FIG. 5. That FIG. 5 shows a Differential Form of a Four Point Resistivity Measurement generally identified with numeral 202. This type of measurement is particularly sensitive and immune to electromagnetic interference. Some engineers also call it a Four Point Resistance Measurement provided the physical dimensions are defined to turn the resistance measured into resistivity. The measurement is being performed on a material 204 that is a fiber-reinforced composite material such as that found in a wing or wing box of a Boeing 787. Such a fiber-reinforced material also includes materials identified as a carbon fiber-reinforced polymer material of the type used in an Airbus A350 wing or wing box. The material 204 has a surface that is defined as âSURFACE OF COMPOSITE UNDER TESTâ, which legend is defined in FIG. 5.
In FIG. 5, electrical current generation means 206 is used to generate electrical current identified with the legend I in FIG. 5. That electrical current I is passed between current conducting electrode A and current conducting electrode B through material 204, legends further identified on FIG. 5. The current conducting circuit shown is completed with insulated wire 208.
In FIG. 5, voltage measurement electrodes C, D, and E are in electrical contact with material 204, which legends are defined in FIG. 5. Current passing between current conducting electrodes A and B will generate a voltage difference V1 between voltage measurement electrodes C and D, which legend V1 is defined in FIG. 5. Current passing between current conducting electrodes A and B will also generate a voltage difference V2 between voltage measurement electrodes D and E, which legend V2 is defined in FIG. 5.
The voltages V1 and V2 are provided to the respective inputs 210, 212, and 214 of processing electronics 216. The inputs are not shown in FIG. 5 for clarity, but would be understood by those of skill in the art. Processing electronics 216 provides detection, amplification, logical processing, and other electronics to provide an output voltage V3, a legend identified in FIG. 5. The output voltage V3 is given by the following:
V3=S1·K1·(R2âR1)ââEquation 1.
In Equation 1, K1 is a proportionality constant that converts resistance to resistivity units appropriate for the geometry of the various defined electrodes in electrical contact with material 204. It should be noted that resistance is normally measured in ohms, and resistivity has the units of ohm-meters. The parameter S1 is an amplification factor sometimes helpful to overcome environmental noise.
Voltage V3 is proportional to the difference in resistance between R2 and R1. The difference in resistance can be measured to many decimal pointsâsix is typical. The inventor has previously done such measurements to an accuracy of eleven decimal places.
The voltage V3 is provided to an input of communications electronics module 218. The input 220 of communications module 218 and the insulated wire 222 carrying voltage V3 are not shown in FIG. 5 for the purposes of clarity but would be understood by those of skill in the art.
In the particular embodiment of the invention shown in FIG. 5, communications module 218 provides the data including V3 to a remote Receiver Unit (224ânot shown in FIG. 5) but understood by those of skill in the art. The communication module 218 provides the data via radio frequency communications 226 that is further identified with legend âDATA OUT=RFâ in FIG. 5.
Power supply 228 provides electrical power to electrical current generation means 206 via insulated wire 230. Power supply 228 also provides electrical power to processing module 216 via insulated wire 232 (numeral not shown in FIG. 5). Power supply 228 also provides electrical power to communications module 218 via insulated wire 233 (numeral not shown in FIG. 5).
In this particular preferred embodiment of the invention, power supply 228 obtains its power from an AC magnetic field identified by the legend âPOWER IN=60 HZ AC MAGNETIC FIELDâ in FIG. 5. In one embodiment, the AC Magnetic Field is provided by a remote Power Transmitter Unit 236 (which numeral is not shown in FIG. 5 but would be understood by a person of ordinary skill in the art). The AC Magnetic field generated by remote Power Transmitter Unit 236 is intercepted by insulated coil of wire 238. The changing AC Magnetic Field induces a voltage in the insulated coil of wire 238 and is used to provide electrical power to power supply 228. In several embodiments of the invention, a battery is included within power supply 228 to store energy received from the remote Power Transmitter Unit 236 that in turn may be used to power elements 206, 216 and 226 in FIG. 5 when the Power Transmitter Unit is not nearby (such as during flight of an aircraft).
The electronic elements, including the current conducting electrodes, the voltage measurement electrodes, elements 206, 216, 218, 228, 230, 238, any electrical conductors required, the remote Power Transmitter Unit 236, and remote Receiver Unit 224 are defined for the purposes herein as a real time electronics measurement system means 240 to provide Differential Four Point Resistivity Measurements of the material 204 under test. The various components of the electronics means 240 may be incorporated within the body of the material 204, or on a surface of the material âidentified by the legend previously described, or any combination thereof in various embodiments.
As stated before, the electrical current generation means 206 generates the electrical current identified with the legend I in FIG. 5. The electrical current I may be chosen to be DC, AC, DC plus AC, or may have an arbitrary function in time. There are advantages to each choice. Depending on the choice, the resulting voltages V1, V2, and V3 will be DC, AC, DC plus AC, or may have an arbitrary function in time.
DC current may be the simplest to implement, but may be subject to adverse noise problems. AC is a good choice, and phase sensitive detection methods may be used to enhance the signal and reduce the effect of any noise present. (For example, see Section 15.15 entitled âLock-in detectionâ in the book entitled âThe Art of Electronicsâ by Horowitz and Winfield identified in the References hereto.) The DC plus AC has some advantages of both. If the current is chosen to have an arbitrary function in time, signal averaging or âsignal stackingâ techniques may be used to enhance the signal and reduce the noise. (For example, see Section 15.13 entitled âSignal averaging and multichannel averagingâ in the book entitled âThe Art of Electronicsâ previously mentioned in this paragraph.)
In a particularly simple approach, the voltage from just one pair V1 can be measured to extract some information especially if combined with phase sensitive detection methods and or signal averaging methods as appropriate.
FIG. 6 shows an experimental arrangement 250 perhaps most suited in a laboratory environment to convey the principles related to the above defined measurement apparatus. A particular sample 252 is a COMPOSITE UNDER TEST, a legend defined in FIG. 6. The current supply 254 provides current I to current conducting electrodes A and B. Voltage measurement electrodes C, D, and E are in electrical contact with the COMPOSITE UNDER TEST 252. Differential amplifiers 256, 258, and 260 provide output voltage V3. In this case, the output voltage V3 is given by:
V3=S2·K2·(R2âR1)ââEquation 2.
In Equation 2, S2 is the appropriate proportionality constant that converts resistance to resistivity units, and S2 is the appropriate overall amplification of the system. FIG. 6 shows a laboratory version of a real time electronics system measurement means 262 to provide Differential Four Point Resistivity Measurements of the material 204 under test. Similar comments made in relation to FIG. 5 for using DC, AC, DC plus AC, and arbitrary waveforms also apply to the current I in FIG. 6.
It is appropriate to return again to FIG. 5. In one embodiment, the apparatus shown in FIG. 5 is a monolithic assembly in contact with the composite. In another embodiment, it is sealed against the surface of the composite under test. In yet another embodiment, it is simply epoxied in place. In another embodiment, an inspector applying a magnetic field from outside the skin of the aircraft, will prompt the device to measure V3 and those results are sent to a receiver box on the exterior of the aircraft (not shown). In another embodiment, the results are sent to a receiver box on the interior of the aircraft (not shown). In various different embodiments, the results can be sent to any selected location (not shown). Furthermore, from such a selected location, the results can be further relayed to other specific locations by suitable communications systems (not shown) as would be appreciated by those of skill in the art upon reading this disclosure.
So, the apparatus can be retrofitted onto a wing box of a 787 by a worker crawling through the crawl space. No extra wires are used to power the apparatus. The apparatus in FIG. 5 does have the sensitivity to detect changes in the microfractures within the composite and the presence of fluids such as water or jet fuel. Such monitoring can be used to prevent the catastrophic failure of composites within the wing box region of the 787. Similar comments apply to other composite structures within the 787 or other aircraft having composite structures such as the Airbus 350.
In yet other embodiments of the invention, it is not necessary to have the solenoid poweredâbattery combination. Rather, in analogy with some old-time wrist watches that needed no winding, a motion powered generator can be made a part of the apparatus shown in FIG. 5. For example, a small round magnet rolling around in a cavity surrounded with pick-up coils can be used to generate power and charge the battery.
Different embodiments of the apparatus in FIG. 5 can perform and store its measurements periodically. After the plane has landed, a hand-held Reader outside the aircraft can then send an RF signal to a receiver coil in the device to âStart Readâ. The RF transmitter can then send RF to the hand-held Reader that receives the data. The hand-held Reader can then be connected wirelessly to a remote computer. The Reader in this paragraph is another embodiment of the Receiver Unit described above.
In another embodiment of the invention, the apparatus shown in FIG. 5 is provided with cell phone-like receiver and transmitter capabilities. After the plane is parked, a call from an external computer to the on-board âcell phoneâ is used to âStart Readâ. Then, data is communicated to the computer that made the callâusing tone's for digits in one embodiment. Tones will work here in one embodiment because not much data is involved in particularly simple embodiments of the invention.
In yet another embodiment of the invention, and if the aircraft itself supports cell phone calls at any location world-wide, then the aircraft supported cell phone network can be used to âStart Readâ and to download the data seamlessly, anywhere in the world, all the time, any time. With such a network, the apparatus in FIG. 5 can be programmed to âwake upâ and send an alarm if the data shows there is a problem.
In yet other embodiments of the invention, similar comments apply to Wi-Fi networks or any other communication networks which aircraft support now and into the future.
For example, one preferred embodiment the following steps are executed:
a. select a portion of the wing box for monitoring;
b. epoxy the measurement apparatus to the portion of the wing box;
c. when the plane lands, the results will be automatically sent by auto-dialing to a cell phone number.
In yet other embodiments, the electrical power and the communications to the measurement apparatus may be made by conventional wiring to aircraft wiring bus. In such case, methods and apparatus defined in U.S. Provisional Patent Application Ser. No. 61/849,585, filed on Jan. 29, 2013 (PPA-101), and in U.S. Provisional Patent Application Ser. No. 61/850,095, filed on Feb. 9, 2013 (PPA-102), and in U.S. Provisional Patent Application Ser. No. 61/850,774, filed on Feb. 22, 2013 (PPA-103) may be used to minimize undesirable effects of Groundloops on the measurement apparatus. Entire copies of these three U.S. Provisional Patent Applications have been previously incorporated in their entirety herein by reference.
The following patents and published patent applications are related to fiber, reinforced and/or composite materials relevant to aircraft. Each is incorporated herein in its entirety by reference.
Each of the following non-patent references is related to the subject matter of the present application and each below identified reference is incorporated herein in its entirety by reference.
The book entitled âDevelopments in Fiber-Reinforced Polymer (Frp) Composites for Civil Engineeringâ, part of the Woodhead Publishing Series in Civil and Structural Engineering, by Nasim Uddin, ISBN 9780857092342.
The book entitled âFiber-Reinforced Composites: Materials, Manufacturing, and Designâ, by P. K. Mallick, © 2007, CRC Press.
The book entitled âStress Analysis of Fiber-reinforced Composite Materialsâ, by Michael W. Haywer, © 2008, Destech Publications, Inc. available through Powell's Books.
And finally, the book entitled âFatigue of Fiber-Reinforced Composites (Engineering Materials and Processesâ, by Anastasios P. Vassilopoulos, © 2011, Springer Publishers.
While the above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as exemplification of preferred embodiments thereto. As have been briefly described, there are many possible variations. Accordingly, the scope of the invention should be determined not only by the embodiments illustrated, but by any appended claims and their legal equivalents that will eventually issue in a relevant patent or patents.
1. A real time electronics measurement system to assess failure of a portion of an aircraft made at least in part with fiber reinforced composite material comprising, measurement means fabricated within the wing and wing-box portion of an aircraft to detect the invasion of fluids and gases into compression induced microfractures of the fiber-reinforced composite materials, communication means for outputting data generated by the measurement means, and a remote receiver for receiving the data output.
2. The real time electronics measurement system of claim 1, wherein the remote receiver comprises at least one of a computer and hand held device.
3. The real time electronics measurement system of claim 1, wherein the communication means transmits data to the receiver by at least one of radio frequency, cellular and Wi-Fi.
4. The real time electronics measurement system of claim 1, wherein the data output from the communication means includes an alarm.
5. The real time electronics measurement system of claim 1, further comprising a communications module that is programmable to automatically initiate transmission of data to at least one remote receiver by the communication means following arrival of the aircraft at an airport.
6. A real time electronics measurement system comprising, measurement means to measure the differential resistivity of fiber reinforced composite materials fabricated within the wing and wing-box portion of an aircraft to detect the invasion of fluids and gases into compression induced microfractures of said fiber-reinforced composite materials, communication means for outputting data generated by the measurement means, and a remote receiver for receiving the data output of the communication means.