Final design review
Download
1 / 41

Final Design Review - PowerPoint PPT Presentation


  • 83 Views
  • Uploaded on

Final Design Review. Fri aei ynCucfed Janine CrsohrO Mihe ernc T io. MEMS-based Corrosion Health Monitoring. Liaison Engineers: Pec uces Tr lw Faculty Coach: Jh .AboePD E. Introduction. Corrosion occurs on electronic chassis of aircraft causes loss of integrity of EMI seal

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Final Design Review' - xandy


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Final design review

Final Design Review

Fri aei ynCucfed

Janine CrsohrO

Mihe ernc T io

MEMS-based Corrosion Health Monitoring

Liaison Engineers: Pec uces

Tr lw

Faculty Coach: Jh .AboePD E


Introduction
Introduction

  • Corrosion occurs on electronic chassis of aircraft

    • causes loss of integrity of EMI seal

  • Lockheed Martin technicians

    • responsible for avoiding critical corrosion damage

    • monitor the health of the chassis on a scheduled basis

      • the chassis is relatively inaccessible within the aircraft

      • in most cases, the chassis is corrosion free

      • time and money are wasted by this inefficiency


Aim

  • To reduce unnecessary corrosion related service activities with a stand alone system that can alert a technician of a needed inspection

    • Reliable measurement of the environmental corrosivity seen by the chassis

    • LED alert system

      • viewed from exterior of the chassis

      • 1-10 level of need for service activity


Business case
Business Case

  • Life cycle cost for the Apache Helicopter fleet* $14.3 billion

  • Percent Dedicated to Inspection** x 25%

    ------------------

  • Inspection cost for the Apache Helicopter $3.575 billion

  • Percent inspections eliminated by SDX-4912 x 33%

    ------------------

  • TOTAL PROGRAM SAVINGS $1.18 billion

  • Life cycle of Apache helicopter* ÷ 20 years

    ------------------

  • TOTAL ANNUAL SAVINGS* $59 million

  • TOTAL LIFE CYCLE SAVINGS/helicopter*** $1.5 million

    *These estimates, in constant fiscal 1994 dollars, are provided in Annex D of the Longbow Apache Test and Evaluation Master Plan, which cites December 1993 estimates from the Longbow Program Office and the President’s fiscal 1995 budget as the original source.

    **Provided from the Military Analysis Network created by the FAS, Federation of American Scientists (non-profit, tax exempt, 501c3organization)

    ***Costs assuming that the SDX-4912 is installed in full apache fleet (assuming fleet size ≈ 800)


Elements of chassis
Elements of Chassis

  • Galvanic coupling of aluminum and nickel

  • Aluminum = anode

  • Nickel = cathode

  • Electrolyte provides driving force for corrosion


Galvanic corrosion
Galvanic Corrosion

  • As a result of nickel contact:

    • Corrosion potential of aluminum (M) increased

    • Corrosion rate of aluminum (M) is increased

Nickel

Aluminum

Couple


Customer requirements
Customer Requirements

GENERAL NEEDS:

Operate Under Harsh Conditions

Non-Intrusive Feedback

Long Life Span

MEMS Based

Light Weight

Small Size



Hardware design
Hardware Design

Functional Diagram




Hardware design2
Hardware Design

Electrical Resistance Sensor Concept:

  • Near Linear Approximation

  • Module Expiration Detection

  • Manufacturability

R = V / Iappl

R = ρL / πr2


Sensor sampling
Sensor Sampling

  • Data sample taken hourly

  • All data stored on Flash

  • Light Emitting Diodes (LEDs)

    • 4 red, 3 yellow, 2 green

    • 1-10 level of corrosion damage

      • Relate to need for technician to perform service activity

      • Level 7 (1st Red LED) correlates to critical corrosion damage


Output method

DA

Output Method

  • Corrosion will cause reduction in ER sensor’s cross-sectional area

  • At critical % area reduction critical voltage


Sensor sampling1
Sensor Sampling

Control Wire



Verification testing
Verification Testing

  • Hardware Unit Test

    • Sensor Proof of Concept

    • 5 days in Salt Spray Machine

  • Software Unit Test

    • Data Interface to software and LED display

  • Acceptance Testing

    • Functional Acceptance Test (Integration)

    • Environmental Acceptance Test (Survivability)


Proof of sensor concept
Proof of Sensor Concept

  • 48 hour test

    -24 hours immersed in salt bath

    -24 hours in atmosphere


Proof of sensor concept1
Proof of Sensor Concept

  • Ground to 50% diameter along longitudinal plane and polished

  • Large cathode (Ni) to anode (Al) ratio

Damage to nickel plating on aluminum wire


Testing
Testing

  • ASTM B117 Salt Fog Chamber

    • Constant corrosive vapor applied for 5 days

    • 5 Test coupons removed at daily intervals

    • Data samplings recorded as voltages

      • Recorded using a datalogger

      • Data sampling = once per minute

Example of Salt Spray Chamber


Wireless zigbee
Wireless - ZigBee

  • Proven feasible up to 6” thickness of casing

    • Due mainly to chamber reflections

    • Minimal aperture required

  • Wireless communication

    pursuit ended 2/7/05

    given risk and manpower




Results1
Results

  • ASTM D3359 Coating Adherence Test

    • Measures Amount of Undercut Nickel Plating

    • Designations: 5A (Least Corrosion)–0A (Most Corrosion)

    • 5 coupons tested

      • 24 hr: 5A

      • 48 hr: 4A

      • 71 hr: 2A

      • 139 hr (1): 1A

      • 139 hr (2): 2A

Coupon 139 hr (1)


Measurement correlation
Measurement Correlation

  • Coupons

    • Minimal corrosion product for 24 & 48 hr coupons

    • Visible Al203 for 71 &139 hr coupons

  • Measurements

    • Rapid Increase in ER sensor at onset

      • Minimal Corrosion Product forming

      • Al+3 ions lost in aqueous solution

    • Resistance change levels off

      • Corrosion product protection


Sensor lifespan
Sensor Lifespan

  • Electrical resistance sensor

    • Survived 5-day salt fog

    • Provided data throughout lifespan of operating board

  • Temperature

    • Survived 2-day salt fog

  • Humidity

    • Survived 1-day salt fog

    • Potentially a conformal coating problem on board


Environmental survivability
Environmental Survivability

  • Harshest of Possible Environments

    • Environmental Sensors

      • not conformally coated

      • survivable in constant spray for 1-2 days

    • Macroscopic System

      • conformal coating spot failures spot corrosion

        • emitted heat from conducting wires

      • survivable in constant spray for 4 days




2

3

4

6

7

5

1



Recommendations
Recommendations

  • Wireless Link

  • Stand-Alone Custom GUI

  • Additional Low Power Research

  • Laser Etched Sensor Manufacturing


Acknowledgements
Acknowledgements

  • Thank You…

    • Lockheed Martin

      • eyunss

      • lew

      • ling

      • Kaara

  • University of Florida

    • ohnAoPE

    • ithanfillD,

    • an M

    • Marilyn Marlow



  • ad