midterm pres

					  Identification of Aging Aircraft
         Electrical Wiring

Woolrich Engineering Consulting Firm




          (“Identification of Aging Aircraft Electrical Wiring,” December 2002)


 Group Members:                                                       Sponsors:
 Robert Beremand                                            Dr. R.O. Stearman
   Chad Hanak                                                   Marcus Kruger
 Melissa Straubel
    History of the Problem

   Faulty electrical wiring                               Solutions
     • Chafing and cracking insulation                       • Visual inspection
     • Electrical fires                                              – Impractical
     • Arcing                                                 • Triboelectric response
                                                                     – May indicate condition of wire




                  (“Identification of Aging Aircraft Electrical Wiring,” December 2002)
Overview
 History of the Problem
 Triboelectric Effect
 Project Objective
 Wire Specimen
 Lab Aging
 Age Analysis
 Work to be Completed
Triboelectric Effect
                                                          Static Electricity
                                                          Frictional force
                                                           causes charge
                                                           imbalance
                                                          Induced current
                                                             • unwanted noise and
                                                               interference
                                                            Magnitude is
(“Identification of Aging Aircraft Electrical Wiring,”
                   December 2002)
                                                             dependent on
                                                             numerous factors
Project Objectives
   Laboratory Aging                 Age Analysis
    • Simulate aging through:         • Does age influence
       – temperature & humidity         triboelectric effect?
            – Hot and cold            • Determine signal
       –   Jet-A fuel                   response to inputs
       –   saltwater solution         • Relate age to
       –   Temperature cycling          measured
       –   combination of all           triboelectric response
    • Visual/Touch inspection         • vibration  wire
                                        current
Alpha Wire Specimen
                         Kapton
                           •   too expensive
                           •   hard to obtain

                         Alpha Wire 1632
                           •   Copper wire with rubber insulation
                  o
                  o


                           •   20 Gauge (thick)
                           •   Stranded, Tinned Copper
                           •   Rubber Insulation
   (Alpha 1632)            •   Low temperature tolerance
                           •   -30o to 90o C

                         Alpha Wire 5825
                           •   28 Gauge (thin)
                           •   Stranded, Silver-plated Copper
                           •   Teflon insulation
                           •   -60o to 105o C
                           •   Low Friction
                           •   High Chemical Resistances

   (Alpha 5852)
Overview
 History of the Problem
 Triboelectric Effect
 Project Objective
 Wire Specimen
 Lab Aging
 Age Analysis
 Work to be Completed
10x The Data

      Previous Cycle                           New Cycle

                                                       Remove
                                        Aging
                         Remove 1                       all 10
 Aging                                  Process
                          Sample                       Samples
 Process
                         at a Time




                                     Return Samples
                                                         Test
                                        to Aging
           Test Sample                                 Samples
                                         Process
           and Do Not
            Return it
Current Work Phase I:
Laboratory Aging
   Temperature and Humidity
     • Previous success with heat alone
         – Go hotter
     • Add Cold Test
     • Temperature Cycles, Temperature Extremes
     • Limited previous results from humidity alone
         – Combine temperature and humidity exposure
         – Freezing and Thawing
     • Tension test ?
   Corrosives
     • Jet-A fuel Soak
         – Visually obvious effects in previous work, swelling
     • Saltwater Soak
     • Residue Effects?
         – Graphite lubricant
   Combination Cycle
Aging Equipment
   Kitchen Ovens
    • Can’t run continuously
   Drying Ovens
    • Remove humidity
   Incubators
    • Most don’t get hot enough

   Environmental Chambers
    •   Large temperature range
    •   Humidity Control
    •   Programmable
                                  (A Bluem Environmental Chamber)
    •   Too expensive               (Courtesy of www.lunaire.com)
Aging Equipment
   Zoology to the rescue!
    • Old Incubator
       –   Humidity control
       –   Adequate heat ?
       –   Working condition   (The Zoology Building (locked on Sundays))
       –   FREE !                   (Courtesy of www.utexas.edu)


    • Old Freezer
       – No humidity control
       – Needs cleaning
       – FREE !
                                              (The Freezer)
Anticipated Results
   Material characteristics should change
    •   Texture
    •   Coefficient of Friction
    •   Capacitance
    •   Resistance


   Changes should be reflected in the triboelctric
    response, and are expected to follow a detectable
    pattern.
Overview
 History of the Problem
 Triboelectric Effect
 Project Objective
 Wire Specimen
 Lab Aging
 Age Analysis
 Work to be Completed
Current Work Phase II:
Age Analysis
   Reconfigure test setup to reduce Electro-
    Magnetic Interference (EMI)
    • Separate data acquisition unit and signal amplifier
    • Connect cases of all units to common ground
    • Encase units in grounded foil to shield from EMI
    • Test for presence of EMI using an EMF meter (to be
      acquired)
    • Make twisted pairs to partially cancel out magnetic
      inductance
        – Tighter twists are more effective
Anticipated Results
  Shaker/Wire Test       •E = portion of energy output
      Setup:             by shaker that is transmitted to
                         wire through friction
               L
                         •E = σhoop(2πrL)µk|dx|
       dx            V
                         •V = V(dE/dt, M1, M2)
Wire
                     R          where M1, M2 are
                                material properties
                         •We expect to find an empirical
                         formula that describes how V
                         changes with age
            Shaker
Anticipated Results
 It’s expected that µk, M1, and M2 all change
  in a predictable manner as the wire
  deteriorates
 At any particular time, the voltage induced
  in the wire can be described as a specific
  function of the excitation frequency
 It is unclear whether or not this frequency
  response will change as the material
  properties of the wire (µk, M1, and M2 )
  change
Work to be Completed
 Acquire aging equipment
  • Have freezer inspected by UT
  • Get technician from Labline to examine
    incubator
 Build new wire testing apparatus
 Cut and twist wire samples
 Construct EMF shielding
Work to be Completed
 Buy EMF meter to verify that EMI has been
  eliminated
 Verify test setup
 Acquire used wire from aviation scrap yard
  in Dallas
 Conduct age analysis on wire specimens
Conclusion
 History of the Problem
 Triboelectric Effect
 Project Objectives
 Wire Specimen
 Lab Aging
 Age Analysis
 Work to be Completed
Identification of Aging Aircraft
       Electrical Wiring




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Description: Electrical wiring instruction document. How to manage Electricity? How to plan a house wiring, safety instructions for Electrical system