NASA Applications of Structural Health National Aeronautics and - - PowerPoint PPT Presentation

▶
nasa applications of structural health
SMART_READER_LITE
LIVE PREVIEW

NASA Applications of Structural Health National Aeronautics and - - PowerPoint PPT Presentation

Jul 12, 2023 168 likes •603 views

https://ntrs.nasa.gov/search.jsp?R=20140010525 2018-08-14T23:57:11+00:00Z NASA Applications of Structural Health National Aeronautics and Space Administration Monitoring Technology W. Lance Richards 1 , Eric Madaras 2 , William H. Prosser 3 , and

slide-1
SLIDE 1

National Aeronautics and Space Administration

NASA Applications of Structural Health Monitoring Technology

  • W. Lance Richards1, Eric Madaras2,

William H. Prosser3, and George Studor 3

NASA Dryden Flight Research Center, Edwards, California NASA Langley Research Center, Hampton, Virginia NASA Engineering and Safety Center, Hampton, Virginia NASA Johnson Space Center, Houston, Texas September 2013

https://ntrs.nasa.gov/search.jsp?R=20140010525 2018-08-14T23:57:11+00:00Z

slide-2
SLIDE 2

National Aeronautics and Space Administration

NASA Focused Structural Health Monitoring

Structures Materials

SHM

NDE

Key Drivers

Vehicle-focused Real-time, decision-making Online processing Onboard systems Lightweight, Small size, Low power, System solutions

Enabling Technologies

Advanced Sensing

  • Multi-parameter
  • Sensor arrays

Advanced Systems and Processing

  • Solid state
  • Rugged
  • High Speed

Ultra-Efficient Algorithms

slide-3
SLIDE 3

National Aeronautics and Space Administration

Reentry ry Reentry Vehicles y es es hicle Vehicle e Vehicle Pressure e re re Pressur Systems re ms ms Composite te Crew e sit te w Module le le Compos Compos Crew Crew

  • s

w International al ternation Space a ion ce ce Spac ce Station e n Vehicle Launch h Launch Vehicles h es es Space Vehicles es Crew Crew w Modul Modul Uninhabited d Uninhabited Aerial Vehicles es es Space Shuttle le le pace Shutt h Orbiter tl tl hutt hutt er er

NASA Structural Health Monitoring Technology

SHM Aerospace Vehicle Applications

3

Sy Ve Ve

slide-4
SLIDE 4

National Aeronautics and Space Administration

4

Topics

  • Structural Health Monitoring

– Definition – SHM vs NDE

  • Agency Overview of SHM Activities

– Accel & Acoustic-based SHM on STS (Prosser, NESC) – Wireless-based SHM on ISS / STS (Studor, JSC) – Piezo-based SHM on ISS (Madaras, LaRC) – Fiber-optic-based SHM on Aerospace Vehicles (Richards, DFRC)

  • Uninhabited Aerial Vehicles
  • Composite Crew Module
  • Reentry Vehicles
  • Space Vehicles
  • Vehicle Pressure Systems
  • Expendable Launch Vehicles
slide-5
SLIDE 5

National Aeronautics and Space Administration

Space Shuttle Orbiter

Wing Leading Edge Impact Detection System (WLEIDS)

slide-6
SLIDE 6

Wing Leading Edge Impact Detection System (WLEIDS) Development

  • Columbia accident investigation testing
  • Recovery of DFI sensor data on MADS focused impact testing
  • n RCC
  • Additional impact testing
  • Ascent impacts
  • MMOD impacts
  • Vehicle testing
  • System development and implementation
  • Flight results
slide-7
SLIDE 7

Columbia Accident Investigation Catastrophic Impact Damage Test on RCC Panel 8

Air Blast Test Accelerations

July 7, 2003

J3 J1 Triax J2

Panel 5 Panel 6 Panel 7 Panel 8 Panel 9 Panel 10

400.00 350.00 0.00 50.00 100.00 150.00 200.00 250.00 300.00

Peak g’s

22.89 18.17 26.60 24.18 18.40 32.57 33.00 30.75 14.39 31.47 35.89 38.43 61.33 22.15 136.60 310.81 254.73 331.71 47.53 67.55 57.01 29.19 42.68 25.76 52.54 32.35 236.03 23.88 6.7 7.3 7.3 7.9 7.9 20.9 20.9 24.3 24.3 37.2 37.2 24.2

1 2 3 4 5 6 7 8

Acoustic Emission Sensor Data

Impact on Panel #8: Broken Panel

8

Accelerometers AE Sensors

1 2 3 4 5 6 7

slide-8
SLIDE 8

National Aeronautics and Space Administration

WLEIDS Operations

  • Installed on all Shuttles
  • Successfully flown on

all flights since Columbia

  • Detected small impacts

during ascent – Small amplitude, nondamaging – Likely popcorn foam

  • Detected several small

MMOD impacts

Sensors and Data Recorder in Wing WLEIDS probable impact signal

slide-9
SLIDE 9

National Aeronautics and Space Administration

9

Topics

  • Structural Health Monitoring

– Definition – SHM vs NDE

  • Agency Overview of SHM Activities

– Accel & Acoustic-based SHM on STS (Prosser, NESC) – Wireless-based SHM on ISS / STS (Studor, JSC) – Piezo-based SHM on ISS (Madaras, LaRC) – Fiber-optic-based SHM on Aerospace Vehicles (Richards, DFRC)

  • Sensor Development
  • Strain-based Parameter Development

– Shape, Loads, Liquid Level, Magnetic Field

  • Sensor Attachment / Characterization
  • System Development
  • Ground / Flight Applications
slide-10
SLIDE 10

Space Shuttle / ISS

Evolution of Micro-WIS Systems

System MicroWIS (SBIR) Extended Life MicroWIS MicroSGU / MicroTAU Wideband MicroTAU Enhanced WB MicroTAU Ultra-sonic WIS (new Ph2 SBIR) Date Certified 1997 2001 2000/2001 2002 2005 2007 Purpose IVHM Thermal Models Cargo Loads Cert Life Extension MPS Feedline Dynamics Wing Leading Edge Impacts ISS Impact/Leak Monitoring Dimensions 1.7” dia. x 0.5” 2.7”x2.2”x1.2” 2.7”x 2.2” x 1.2” 3.0”x 2.5” x 1.5” 3.25”x2.75”x1.5 3.4” x2.5”x 1.1” Sample Rate Up to 1Hz Up to 1Hz Up to 500Hz (3 channels) Up to 20KHz (3 channels) Up to 20KHz (3 channels) Up to 100KHz (10 channels) Data Storage None 2Mbytes 1Mbyte 256Mbytes 256Mbytes 1Gbyte Battery Life 9 months 10+ years 2-3 missions 1 mission 1 mission 3 years Sensor Types Temperature (Flight Cert) and Resistive sensors: Strain, Accelerometer, Pressure Temperature (Flight Cert) and Resistive sensors: Strain, Accelerometer, Pressure Acceleration & Strain (Flight Cert) or Resistive

  • sensors. Includes

Pressure as Trigger Channel. Accelerometer & Temperature (Flight Cert) or Piezoelectric and Resistive Sensors Accelerometer & Temperature (Flight Cert) or Piezoelectric and Resistive Sensors Ultrasonic Microphone and Acoustic Emission

Columbia Shuttle fleet ISS assembly DIDS

slide-11
SLIDE 11

National Aeronautics and Space Administration

Wireless Instrumentation Systems

Unique Solutions To Real Shuttle Problems

  • Temperature Monitoring
  • Validation of thermal models for design modifications and operations
  • Micro-WIS (first flown in non-RF configuration)
  • Structural Loads and Dynamics
  • SSME support strain data needed for certification life predictions
  • Cargo to orbiter trunion dynamics and loads
  • Micro Strain Gauge Unit (Micro-SGU) and Micro Tri-Axial Accelerometer

Units (Micro-TAU)

  • SSME Feed-Line Crack Investigation
  • Main propulsion system flow-liner dynamics
  • Wide-Band Micro-TAU
  • Wing Leading Edge Impact Detection
  • Sense impact of ascent debris and MMOD on-orbit
  • Enhanced Wide-Band Micro-TAU (EWBMTAU)
  • SRMS On-Orbit Loads
  • Increases needed to support contingency crew EVA repairs at end of

boom

  • Wireless Strain Gauge Instrumentation System (WSGIS) and EWBMTAU
  • Also used for monitoring Shuttle Forward Nose dynamics during roll-out
slide-12
SLIDE 12

National Aeronautics and Space Administration

ISS Structural Dynamics Accelerometers

Current accelerometer count on ISS is 81 (SDMS: 33 EWIS: 30 IWIS: 18).

Internal Wireless Instr System Structural Dynamics Measurement System External Wireless Instr System

slide-13
SLIDE 13

National Aeronautics and Space Administration

13

Topics

  • Structural Health Monitoring

– Definition – SHM vs NDE

  • Agency Overview of SHM Activities

– Wireless-based SHM on ISS / STS (Studor, JSC) – Accel & Acoustic-based SHM on STS (Prosser, NESC) – Piezo-based SHM on ISS (Madaras, LaRC) – Fiber-optic-based SHM on Aerospace Vehicles (Richards, DFRC)

  • Sensor Development
  • Strain-based Parameter Development

– Shape, Loads, Liquid Level, Magnetic Field

  • Sensor Attachment / Characterization
  • System Development
  • Ground / Flight Applications
slide-14
SLIDE 14

National Aeronautics and Space Administration

Distributed Impact Detection System Concept

  • Original DIDS concept is to detect and locate impacts via a

wireless sensors system.

  • Current DIDS system concept is to detect leak locations on

space vehicles.

MMOD strike example

Impact

Structural Waves Piezoelectric Sensors

DIDS System Concept Module is asleep until event signal threshold is crossed. Sensor module can record four signals at 1MHz rate. Sensors can record and transmit ~6000 events. Batteries can last up to 5 years. Laptop computer can control multiple units.

slide-15
SLIDE 15

09/12/07 15

Crew laptop on ISS Server

DIDS Wireless Sensor Units DIDS Wireless Receiver tethered to crew laptop

Note: All Sensor hardware is Internal

DIDS Wireless Sensor Units

slide-16
SLIDE 16

ISS Ultrasonic Background Noise Test (UBNT)

System Overview

910Mhz

DIDS

Digital Wave - Piezoelectric AE Sensor:

  • Model B-225.5
  • Frequency bandwidth: 50kHz - 400kHz
  • Temperature range: -50°C to +100°C
  • Dimensions: 0.625” diameter. x 0.8" H
  • Connector type: Microdot

Sensor Cable

  • Length: 2 Meters

Sensor Cable

  • Length: 2 Meters

DIDS Power Supply WLE L91 Battery Pack 2 – Energizer L91 AA batteries 3.0 VDC output (nominal) Antenna/Data Cable

  • Length: 2 Meters
  • SMA connector
  • Teflon jacket
  • Kynar heat shrink

910Mhz

SSC

DIDS Receiver connected to SSC via USB

Power supply and DIDS sensor units attached to ISS Module pressure wall using velcro. AE sensors attached using pre- certified adhesives.

JSL File Server

OCA/Ground

Certified Ethernet cable

NOTE: Diagram illustrates system configuration by ISS Module. No more than 7 DIDS sensor units will used in any ISS Module.

Principal Investigator (LaRC)

  • In order to detect leaks, the amplitude of the ultrasonic

background noise levels is required. System is on orbit in the ISS awaiting astronaut time for installation

slide-17
SLIDE 17

Example of installation behind ISS equipment ramp

(Fit Check in B9 US Lab Mockup)

UBNT Extended Antenna in ISS hallway DIDS unit installed in open rack in mockup

slide-18
SLIDE 18

National Aeronautics and Space Administration

18

Topics

  • Structural Health Monitoring

– Definition – SHM vs NDE

  • Agency Overview of SHM Activities

– Accel & Acoustic-based SHM on STS (Prosser, NESC) – Wireless-based SHM on ISS / STS (Studor, JSC) – Piezo-based SHM on ISS (Madaras, LaRC) – Fiber-optic-based SHM on Aerospace Vehicles (Richards, DFRC)

  • Uninhabited Aerial Vehicles
  • Composite Crew Module
  • Reentry Vehicles
  • Space Vehicles
  • Vehicle Pressure Systems
  • Expendable Launch Vehicles
slide-19
SLIDE 19

National Aeronautics and Space Administration

Reentry ry Reentr ry Vehicles y es es hicle Vehicle e Vehicle e Pressure e re re Pressur Systems re ms ms ms Composite te Crew e

  • sit

te w Crew w Module e Compo Compo Crew Crew

  • w

International al ternation Space a ion ce ce Spac ce Station e n Vehicle e Launch h Launch Vehicles h es es Space Vehicles es Modul Modu ul l hi l UAVs Vs Space Shuttle le

NASA Structural Health Monitoring Technology

SHM Aerospace Vehicle Applications

19

Syst Ve Ve

slide-20
SLIDE 20

National Aeronautics and Space Administration

20

Fiber Optic Sensing System (FOSS)

Background

  • Dryden initiated fiber-optic instrumentation

development effort in the mid-90’s

– Dryden effort focused on atmospheric flight applications of Langley patented OFDR demodulation technique

  • Dryden focused on developing system

suitable for flight applications

– Previous system was limited due to laser technology – System limited to 1 sample every 90 seconds

  • Dryden initiated a program to develop a

more robust / higher sample rate fiber optic system suitable for monitoring aircraft structures in flight

  • Partnering with Kennedy Space Center,

Launch Services Program, Dryden has developed a comprehensive portfolio of intellectual property that is now ready to be commercialized by the private sector.

Ground to Flight Fiber-Optic Sensing Technology Development

X-33 IVHM Risk Reduction Experiment

slide-21
SLIDE 21

National Aeronautics and Space Administration

21

Fiber Optic Sensing System (FOSS)

Operation Overview

Fiber Optic Sensing with Fiber Bragg Gratings

  • Multiplex 1000s of sensors onto one “hair-like”
  • ptical fiber
  • All gratings are written at the same wavelength
  • Uses a narrowband wavelength swept laser

source to interrogate sensors

  • In addition to measuring strain and temperature,

these sensors can be used to determine a variety

  • f other engineering parameters

Reflector

  • L1

L3 L2

Laser light Loss light Reflected light (IR) Laser tuning start stop

  • i

i i R

nL k Cos R I ) 2 (

Ri – spectrum of ith grating n – effective index L – path difference k – wavenumber

  • 2
  • k

Grating region Tuning direction

slide-22
SLIDE 22

National Aeronautics and Space Administration

22

Dryden’s FOSS

Current Capabilities

Flight System

22

Predator -B in Flight Flight System

Current system specifications

  • Fiber count

8

  • Max sensing length / fiber

40 ft

  • Max sensors / fiber

2000

  • Total sensors / system

16000

  • Max sample rate (flight)

100 sps

  • Max sample rate (ground)

60 sps

  • Power (flight)

28VDC @ 4.5 Amps

  • Power (ground)

110 VAC

  • User Interface

Ethernet

  • Weight (flight, non-optimized)

27 lbs

  • Weight (ground, non-optimized)

20 lbs

  • Size (flight, non-optimized)

7.5 x 13 x 13 in

  • Size (ground, non-optimized)

7 x 12 x 11 in

Environmental qualification specifications for

flight system

  • Shock

8g

  • Vibration

1.1 g-peak sinusoidal curve

  • Altitude

60kft at -56C for 60 min

  • Temperature
  • 56 < T < 40C

Ground System

slide-23
SLIDE 23

National Aeronautics and Space Administration

Fiber Bragg Grating – Optical Frequency Domain Reflectometry

FBG-OFDR can dramatically improve structural and system efficiency for space vehicle applications by improving both affordability and capability by …

  • Providing >100x the number measurements at

1/100 the total sensor weight

  • Providing validated structural design data that

enables future launch systems to be lighter and more structurally efficient

  • Reducing data system integration time and cost

by utilizing a single small system for space / launch vehicles

  • Increasing capability of measuring multiple

parameters in real time (strain, temperature, liquid level, shape, applied loads, stress, mode shapes, natural frequencies, buckling modes, etc.

  • Providing an unprecedented understanding about

system/structural performance throughout space craft and mission life cycle

y by …

Centaur Coupon shown at PPBE review

  • n shown at PPBE rev

ISS COPV strain & temp monitoring Liquid level sensing d level g sing ISS COPV strain & i & monitoring Shape sensing for vehicle control

Centaur Coupo

  • n show

Liqui sen s Pressure monitoring

slide-24
SLIDE 24

National Aeronautics and Space Administration

24

Composite Crew Module

NASA NESC - Strain Sensing

  • Four fibers were installed

around the module’s three windows and one hatch

  • 3300 real-time strain

measurements were collected at 30Hz as the module underwent 200%DLL pressurization testing

  • Measured strains were

compared and matched well to predicted model results

  • Project concluded:
  • “Fiber optics real-time

monitoring of test results against analytical predictions was essential in the success of the full-scale test program.”

  • “In areas of high strain

gradients these techniques were invaluable.” Inner Hatch FBG Strains, Max Pressure

Microstrain (in/in) Predicted

  • 2000

FBG 2000 4000

slide-25
SLIDE 25

National Aeronautics and Space Administration

25

Uninhabited Aerial Vehicles

Global Observer UAS - Aerovironment

  • Validate strain predictions along the wingspan
  • Measured strain distribution along the centerline top and

bottom as well as along the trailing edge top and bottom.

  • FO Strain distribution measurements are being used to

interpret shape using Dryden’s 2D shape algorithm

  • A 24-fiber system was designed of which 18, 40ft fibers

(~17,200 gratings) were used to instrument both left and right wings

slide-26
SLIDE 26

Dryden Flight Research Center

Uninhabited Aerial Vehicles

Global Observer UAS - Aerovironment

  • Proof-load testing of components and large-scale structures

Wing Span: 175 ft

Global Observer Wing Loads Test

26 Whiffletree Loading System

slide-27
SLIDE 27

National Aeronautics and Space Administration

Uninhabited Aerial Vehicles

Global Observer (AV) - 2D Shape Sensing Results

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

  • 0.2

0.2 0.4 0.6 0.8 1 1.2 Predicted vertical wing displacement (Fiber 3) vs. Actual displacement Wing Span (normalized) Displacement (normalized) Predicted vertical wing displacement Actual: Photogrammetry in GRF Actual: Photogrammetry in RRF

100% DLL 0% DLL 50% DLL 80% DLL 30% DLL

0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 9 2

Over the entire wing span, the predicted displacements of fiber 3 closely match the actual for every load condition. 1 2 3 4 FWD AFT

27

slide-28
SLIDE 28

National Aeronautics and Space Administration

28

UAVs - Global Observer UAS (AV)

Flight Testing of Strain and 2D Shape Sensing

  • Validate strain predictions along

the left wing in flight using 8, 40ft fibers (~8000 strain sensors)

  • An aft fuselage surface fiber was

installed to monitor fuselage and tail movement

  • Strain distribution were measured

along the left wing centerline top and bottom as well as along the trailing edge top and bottom.

  • 8 of the 9 total fibers are attached

to the system at any give time

  • The system performed well and

rendered good results

28

slide-29
SLIDE 29

National Aeronautics and Space Administration

29

Ikhana in Flight

  • 18 flights tests conducted; 36 flight-hours logged
  • Conducted first flight validation testing April 28, 2008
  • Believed to be the first flight validation test of FBG strain and wing

shape sensing

  • Multiple flight maneuvers performed
  • Total of 6 fibers (~3000 strain sensors) installed on left and right wings
  • Fiber optic and conventional strain gages show excellent agreement
  • FBG system performed well throughout entire flight program

Predator-B UAS - Flight Testing

Strain and 2D Shape Sensing

Video clip of flight data superimposed on Ikhana photograph Ikhana in Flight

y p g g p g

Video clip of flight data superimposed on Ikhana photograph

slide-30
SLIDE 30

National Aeronautics and Space Administration

ENGINEERING PROPERTIES OF COMPOSITE MATERIALS. Material Properties Woven fabric Toray-T700G Unidirectional fabric Toray-T700S Foam core DIAB Divinycell HT 50 E11, GPa 5.54 x 101 1.19 x 102 8.50 x 10-2 E22, GPa 5.54 x 101 9.31 x 100

  • G12, GPa

4.21 x 100 4.21 x 100

  • ν12

3.00 x 10-2 3.10 x 10-1 3.20 x 10-1 ρ, kg/m3 1.49 x 103 1.52 x 103 4.95 x 10-1

Full-Scale Composite Wings

Strain, Applied Loads, and 2D Shape - Mississippi State

30

slide-31
SLIDE 31

National Aeronautics and Space Administration

F, N Measured δL, m Calculated δL, m

Error, %

1373

  • 0.184
  • 0.178

3.02 1592

  • 0.209
  • 0.205

2.29 1837

  • 0.241
  • 0.231

4.08 2036

  • 0.265
  • 0.257

3.23 2269

  • 0.295
  • 0.284

3.75 MEASURED AND CALCULATED WING TIP DEFLECTIONS Applied Load, N Calculated Load, N Error, % Difference, N

  • 185.5
  • 178.8

3.60 6.7

  • 194.4
  • 210.0

7.98 15.5

  • 241.5
  • 252.0

4.35 10.5

  • 288.5
  • 291.5

1.05 3.0

  • 333.3
  • 332.9

0.12 0.4

  • 378.1
  • 381.1

0.80 3.0

  • 422.9
  • 435.9

3.07 13.0

  • 472.2
  • 486.4

3.01 14.2 Average EI=98728.2-N*m2

OUT-OF-PLANE APPLIED LOAD

Test Procedure for displacement

  • Collect FBG strain data
  • Use displacement Eq. and Strain

data to calculate deflection

Test procedure for out-of-plane loads

  • Determine EI for the wing
  • Determine moment acting on wing
  • Determine Load applied

Full-Scale Composite Wings

Strain, Applied Loads, and 2D Shape - Mississippi State

31

slide-32
SLIDE 32

National Aeronautics and Space Administration

Next Generation Structural Health Monitoring on Reentry Vehicles

Personal Observations

  • The Shuttle never returned in the

same condition as when it launched

  • Flight operations always reveals the

unexpected and make known the unknowns

  • NASAs SHM fiber optic sensors are

much lighter than conventional strain gage sensors

  • FOSS-OFDR provides massive

amounts of quantitative structural performance information in real time and for post test analysis

  • This quantitative information can
  • vercome some of the unknown

unknowns that may allow you to fly another day

Dream Chaser Re-entry (artist conception)

STS Landing at Edwards AFB Post-flight Inspection

slide-33
SLIDE 33

National Aeronautics and Space Administration

Monitoring of MMOD Impact Damage to TPS

NASA Dryden / CSIRO Australia collaboration

33

Objective

  • Detect & evaluate Micrometeoroid and

Orbital Debris (MMOD) impact damage to Thermal Protection Systems (TPS) using embedded acoustic and thermal sensor networks

Principles

  • Detect and locate impacts using acoustic

emission sensor networks

  • Evaluate severity of damage with optical

fiber thermal sensor network

  • Utilize centralised or self-organising
  • peration with local network architecture
  • n modular tiled structure

Novel aspects

  • Development of switched optical fiber

sensor network to enhance robustness

  • Capable of central control or autonomous

self-organising operation.

  • Functional damage evaluation – monitor

effect on thermal properties.

33 Vehicle Re-entry (artist conception) TPS health monitoring system Heat shield with TPS Heat shield Test Setup at Dryden Two TPS modules

slide-34
SLIDE 34

National Aeronautics and Space Administration

Vehicle Pressure Systems

Embedded Strain - The Multidisciplinary Challenge

  • Fiber Optic Sensors embedded within Composite

Overwrapped Pressure Vessels

  • Goal is to understand embedded FBG sensor response

– Requires comprehensive, multi-disciplinary approach

+

34

slide-35
SLIDE 35

National Aeronautics and Space Administration

Vehicle Pressure Systems

Composite Overwrapped Pressure Vessels (COPVs)

Objectives

  • Perform real-time in-situ structural monitoring of COPVs with

embedded fiber Bragg grating sensor arrays

  • Develop analytical and experimental methods to reliably

interpret embedded strain sensor measurements

  • Develop a robust “early-warning” indicator of COPV

catastrophic failure

  • Provide finite-element-like experimental strains in real time for:

− Health Monitoring on International Space Station − Model validation to improve future designs

Approach

  • Develop and evaluate surface-attachment techniques
  • Install surface fiber optic sensors
  • Conduct test to 80% of burst pressure
  • Overwrap surface FBGs with composite layers
  • Install new surface FBGs over “embedded” FBGs
  • Conduct burst test
  • Develop data analysis and visualization techniques to

reliably predict COPV failure

  • r:

h

NASA Dryden and WSTF test team 35

slide-36
SLIDE 36

National Aeronautics and Space Administration

Composite Overwrapped Pressure Vessels

Installation Methods Installation methods developed

  • Transfer pattern to bottle surface
  • Mask and fill basecoat paths
  • Sand down close to surface layer
  • Route and attach FBGs

p y

36

slide-37
SLIDE 37

National Aeronautics and Space Administration

37

Embedded Fiber to 5000 psi

Hoop Direction

  • 1000

1000 2000 3000 4000 5000 6000 500 1000 1500 2000 2500 3000 3500

Strain (με) TT (sec)

F1eG161 F1eG174 F1eG187 F1eG201

  • 1000

1000 2000 3000 4000 5000 6000 1000 2000 3000

Strain (με) TT (sec)

F1eG343 F1eG356 F1eG369 F1eG382

0° 90° 180° 270°

H_5 H_7

slide-38
SLIDE 38

National Aeronautics and Space Administration

FOSS Current and Future Work

Flight Demonstration on a Launch Vehicle (KSC-Launch Services)

38

TPS S Health th TPS ealt H Monitoring th ng ng g Embedded d mbedded Strain d ded d n Strain n 3D D Shape pe Temperature and emperature an Cryogenic an c Cryogenic c Liquid Level c el el Applied Loads ds Magnetic Field d 2D Shape pe d d

Na

Ap

slide-39
SLIDE 39

National Aeronautics and Space Administration

Cryogenic Liquid Level-Sensing

The Challenge

  • The transitional phase between

liquid and gas of cryogenics is difficult to discriminate while making liquid level measurements

  • Using discrete cryogenic

temperature diodes spaced along a rake yields course spatial resolution of liquid level along with high wire count

FOSS Approach

  • While using a uniquely developed

fiber optic structure (CryoFOSS), the transitional phase can be mapped more accurately

  • Using a single continuous grating

fiber, a high degree of spatial resolution can be achieved, as low as 1/16”

Cryogenic Rake w/ silicon diodes & FOSS fiber Cryogenic c Rake w/ s enic Liquid level Silicon Diode Cryogenic Container / y g FOSS Fiber Cryogenic Container located at MSFC (below deck) Cryogenic Container located at MSFC (above deck) 1st Gen CryoFOSS Test Results 39

slide-40
SLIDE 40

National Aeronautics and Space Administration

LH2 Testing of CryoFOSS at MSFC

Objective

  • Experimentally validate CryoFOSS using Dryden’s

FOSS technology

Test Details

  • Dewar dimensions: 13-in ID x 37.25-in
  • Fill levels of 20%, 43%, and 60% were performed
  • Instrumentation systems

− Video boroscope with a ruler (validating standard) − Cyrotracker (ribbon of 1-in spaced silicon diodes) − MSFC Silicon diode rake − Fiber optic LH2 liquid level sensor(CryoFOSS)

Results

  • CryoFOSS sensor discerned LH2 level to ¼” in

every case

  • Excellent agreement achieved between

CryoFOSS, boroscope, and silicon diode Cryotracker

Bottom line

  • Validated concept for a lightweight, accurate,

spatially precise, and practical solution to a very challenging problem for ground and in-flight cryogenic fluid management systems

40 40

Cryo-FOSS

n’s

d) s)

slide-41
SLIDE 41

National Aeronautics and Space Administration

LH2 Liquid Level Results

CryoFOSS compared to Boroscope Combined Results

41

slide-42
SLIDE 42

National Aeronautics and Space Administration

Objective

  • To utilize the same magnetically sensitive particles that

birds use, for example, to sense Earth’s magnetic field for migratory purposes

Application

  • Installing distributed magnetic sensors on a structure

could help with navigation

  • Identifying disturbances in Earth’s magnetic field could

indicate the presence of another vehicle or a missile

Approach

  • Fabricate new fiber optic sensor with greater sensitivity to

magnetic field (H)

  • Apply magnetic field to sensors
  • Measure wavelength shifts (ΔλB)
  • Behavior of λB should follow magnetization behavior of

modified sensor

Results

  • Experimental results corroborate the theory
  • Currently developing new methods for increasing

sensitivity of detecting magnetic fields

Lohmann, Nature, V.464 (2010)

Magnetic Field Sensing

NASA Dryden / UCLA collaboration

Fiber optic Magnetic Field Sensor Modified FBG sensor Un- modified FBG sensor 42