Date post: | 04-Aug-2015 |
Category: |
Documents |
Upload: | charles-nichols |
View: | 142 times |
Download: | 3 times |
Composite Pressure Vessel/ Rocket Propulsion Inspections
Regor Saulsberry (575) 635-7970
Overview
• Quick overview of JSC-WSTF• Interesting Projects I have done and a reflection
on the Shuttle Program• Nondestructive Evaluation (NDE) and related
Structural Health Monitoring
2
3
Orbiter and transport over the WSTF 300 area
4
5
Simulated altitude testing of full-scale integrated hypergolic propulsion systems
Large-scale explosion testing of hypergolic, cryogenic, Solid, and most new “green” propellants
Component testing in high temp/high flow gaseous oxygen and hydrogen
Repair depot for components in the toxic hypergolic propellant, oxygen, and hydrogen systems aboard Shuttle and ISS
White Sands Space Harbor (WSSH) Flight tests Agency facility for hypervelocity impact testing, including
accommodations for hazardous targets Capability for all materials testing defined by NASA Standard
6001 (NHB 8060.1C) Design and hazards analysis of oxygen and hydrogen systems
Unique Capabilities
WSTF Propulsion Test Activities
Eight engine/system test stands (5 vacuum cells)
Long-duration high-altitude simulation
Hypergolic and cryogenic liquid rocket systems
Flight component repair and refurbishment
Propulsion Test Area 400
Flushing Primary RCS thrusterpropellant valve
Rocket Engine Firing Inside Vacuum Test Cell
Altitude Simulation System Operation for Rocket Engine Tests
WSTF Laboratories Test Activities
• Oxygen Hazards Assessment• Ignition & Combustion Testing
• Component Development, Acceptance & Qualification
• NHB 8060.1 Testing• Propellant Characterization
• Material Compatibility
Propellant & Explosion Hazards Assessment Hypervelocity Impact Testing
8
Molecular Analysis of Surface Effects Using X-ray Photoelectron Spectroscopy Instrument
Other X-ray:• SEM EDAX• CT (up to 450
KV)
9
Hypervelocity and Low Velocity Impact Test Facilities
.07, .17, .30, .50, and 1 caliber two-stage light gas guns capable of propelling 0.25 to 22 mm projectiles in excess of 7.0 km/s (16,000 mi/h)
Shuttle Window Pit Caused by Paint Chip
WSTF Nondestructive Evaluation Capability
Traditional:• Thermography: pressurized, flash, heat soak and through transmission • HD Shearography: pressurized, thermal excitation• Radiography • X-ray CT: metals and composites• Ultrasound: A-scan, B-Scan, C-scan, thickness measurement• Handheld eddy current probes and bolt scanner • Certified visual inspection and training classes
New Methods • Laser profilometry: scanning of Composite overwrapped pressure vessels (COPVs)• Eddy current: scanning of COPV liner (inside and out)• Raman Spectroscopy (strain and stress rupture progression)
Structural Health Monitoring • Matrix ultrasonic senses (i.e., Acellent and Metis)• Acoustic Emission: Acceptance testing, Damage detection and failure prediction • Surface and embedded Fiber optic health monitoring: strain, acoustic, shape sensing
10
12
Computer &Imaging Software
Phase StepperController
PhaseShift Mirror 2 Axis
TiltMirror
Laser : Narrow Line, Variable Diffusion Beam
Test Part Stress
Controller & Sensors
Vacuum Thermal Vibration
Monitor Images & Data
ShearographyImage Calibration
Device/Data
CCDCamera
PhaseStepper
BeamSplitter
Test Part (Honeycomb Panel Shown)
Test PartStress Device(Thermal Shown)
Disbond Skin to Core
P1
P2
Shearography NDT System Schematic Diagram
Shearography Test Results By Stress Method
Thermal Shearography Aluminum Honeycomb Panel
Pressure Shearography COPV
Vacuum ShearographyComposite/Nomex Honeycomb
Acoustic ShearographyFoam Cryogenic Fuel Tank TPS
Carbon Fiber/Nomex Core Shearography NDT Std.
• Double/Single Teflon Inserts• Milled Flat Bottom Holes• Representative Foreign Material in composite layers
0.25 0.5 0.875 1.5 inches
0.08 Delamination
25 Ply Carbon Fiber Laminate Panel With Teflon Insert
• Well consolidated Carbon fiber laminate • Round Teflon Insert is seen with Thermal shearography.
• Smaller disbond seen on top of insert.
High Definition Shearography
Composite overwrapped pressure vessel inspection (top) and thermal shearograph of a vessel with delaminations and a void (bottom)
• The LTI-5100HD Advanced Shearography System, equipped with a TES-200 thermal excitation unit, has greatly improved the ability to baseline the received stress state and monitor and identify visually undetectable subsurface impact damage. – The need is to correlate damage to
response and do POD studies– Physical defect standards help
17
Pressure shearograph of COPV impacts delivered using a 0.5 in. ball-end tup
“Smart COPV”Integrated COPV Structural Health
Monitoring (SHM) Systems That Target Space Exploration and ISS Needs
Background Cont’d
• Future NASA missions may not be successful without SHM (ref. OCT Roadmaps)
• Potential near-term needs include carbon-epoxy (C/Ep) COPVs used on ISS, ISS Nitrogen-Oxygen Recharge System (NORS) if reused, the Orion crew and service modules, and as nearly all future long duration NASA spacecraft missions– Incidental but direct benefits also exist for COPVs used in DOT liquid natural gas
and hydrogen storage applications– Other composite structures of interest are load bearing, fracture critical composite
materials used in DoD, commercial aerospace and NASA applications (the latter include composite structures being developed under NASA‘s Composites for Exploration program plus several precursor programs (i.e., LSSM, both wet and dry structures), especially where cyclic loading is experienced
19Nitrogen Tank Assembly (45”L×19.7”D)
High Pressure Gas Tank - OxygenHPGT COPV (37.89”D)
Las Gatos COPV Results
FBGs
AE
WSTF COPV burst prediction
GRC AE Analysis Applet LaRC DIDS AE DFRC FBG strain measurement
KSC MSG stress measurement
AE waveform analysis
MSFC FOAE
WSTF FR Analysis Tool Smart COPV
WSTF/LaRC Eddy Current &
Profilometry
Project Details by Center
21
2222
WSTF COPV Profilometry and Eddy Current Scanners
Figure 1 – WSTF Cylindrical COPV Mapping System
Upper Vessel Positioning Stage
Linear Stage Sensor
Lower Vessel Positioning Stage
Calibration Fixture
Vessel Plug Centering Guide
Original Internal Profilometer
X-Y Coupon Scanner developed
External Profilometer added to Original Scanner
External Eddy Current (EC) Probe added
Articulated sensor developed to inspect COPV domes in NORS
Internal Profilometer
12-foot Orion Internal Profilometer developed and verified on simulator vessel
7-foot NORS Internal Profilometer developed, verified and actively being used by the
ISS NORS Program
23
Outrigger arms
Delivery shaft
Laser exit port
Laser receiving port
Second Generation Laser Profilometry
Articulated sensor allows scanning of Ellipsoidal ends
24
Laser Profilometry of COPV interior surface quantifies liner buckling which is difficult to inspect by other methods
Calibration traceable to National Standard and demonstrated better than 0.001 accuracy/repeatability on 26-in and better than 0.002 accuracy/ repeatability on 40-in
25
NESC Assisting with Internal EC Scanner Being Developed (shown deployed)
25Internal EC probe shown interfaced to existing
laboratory stage
Collapsible internal EC probe deployed for scans (conceptual design)
Scans of NNWG Vessel following Stress Rupture testing
Internal (left) and external (right) radial scans of the same vessel.26
WSTF: Automated AE for COPV Pass/Fail
Goal: Develop acoustic emission SHM hardware for ISS• Automate FFT batch processing• Implement AE pattern recognition• Promulgate consensus pass/fail criteria for COPVs
Approach: Statistical Physics vs. Stochastic model used• Determine ‘in-family’ behavior of well-characterized specimens/test articles• Predict behavior of unknown based on population response• Tailor method to actual in-service pressure schedules
Status: In-house software & AE methods developed• FR analysis software developed
– Statistical methods developed– Application of above methods to COPVs demonstrated– EWMA ‘knee’ method developed (excellent preliminary results)
• Data acquisition parameters optimized• Response surfaces for C/Ep materials-of-construction generated• Burst pressure for a COPV predicted
27
Felicity Ratio Analysis Tool (FRAT)
C/Ep Strand Testing
Load Ratio
0.0 0.2 0.4 0.6 0.8 1.0
Fe
lic
ity
Ra
tio
0.8
0.9
1.0
1.1
1.2
1.3
0.8
0.9
1.0
1.1
1.2
1.3
T1000 carbon/epoxy towIM-7 carbon/epoxy towKevlar 49/epoxy towIM-7 carbon/epoxy COPV
C/Ep Comparative Damage Tolerance
Burst Prediction for COPVs
GRC: Acoustic Emission Analysis Applet
28
• Rewrote for UNLIMITED data set size• All events available for viewing in Applet
using slider control• Translator from .WAVE NDF
incorporated into Applet• Can subset and threshold events for
analysis• Time/Event File generated• AE Statistics vs. Time generated/saved to
spreadsheet file• User Manual written• Currently being beta-tested by WSTF
Goal: • Develop an Acoustic Emission Analysis
Applet to produce a ‘Smart’ real-time analysis capability to support NASA missions
Approach:• Use consensus AE waveform
characterization parameters, e.g., amplitude, counts, rise time, duration, centroid and peak frequencies, etc., to differentiate composite damage event
Status:Acoustic Emission Analysis Applet derived from AEAA software:
New Input FY12
LaRC - Application of DIDS Hardware to COPVs
Goal: • Demonstrate the ability of flight certified hardware to
perform AE measurements in COPVs
Approach: • Evaluate the ability of the Distributed Impact Detection
System (DIDS) to capture AE events during testing
• Evaluate system’s throughput vs. the requirements of a measuring a COPV
• Assess the DIDS’ ability to function as an IVHM system
29DIDS system installed behind rack in Node 2
DIDS system with sensors and short cables
Status: • DIDS hardware has been certified for on-orbit application
and is currently on orbit, being used to support the SDTO project UBNT
Goals: Define Critical Damage Accumulation (CDA) in Composite Overwrap Pressure Vessel (COPV) before stress rupture occurs and corroborate (CDA) with a know NDE inspection standard: AE Felicity ratio; Additional, damage severity and location is desired.
MSFC: Smart Layer for Smart COPV
Approach:1. Perform cycle testing of COPV until Keizer effect is violated.
At reduced loading, damage index will be measured.2. Leverage funding from OCT and Composite for Exploration
Status: 1. Tested composite laminate with foam core.2. Currently have three 18’” COPV that will be
tested at MSFC and possibly one at WSTF.
FBGs
COPV integrated Smart layers
Impacts on sandwich foam. Damage was located and quantified by Acellent Smart Patch.
DFRC: Embedded Fiber Bragg Gratings
Objectives • Perform real-time in-situ structural monitoring of COPVs by
acquiring 100s of fiber Bragg grating measurements from sensors embedded within the composite structure of the COPV
• Develop analytical and experimental methods to reliably interpret strain measurements from embedded FBG sensors
• Develop a robust “early-warning” indicator of COPV catastrophic failure
Approach• Analytically model the embedded FBG sensors• Attach 100s of FBG sensors to outer COPV
surface• Conduct baseline testing of surface FBGs• Overwrap bottle (surface FBGs become
embedded)• Instrument new sensors on new outer surface• Test to failure; correlate data at each step
Status: • Hypercomp COPV Testing Complete
• Instrumented COPV with 1600 FBGs (800 embedded and 800 surface mounted)
• GD T1000 Bottle – Surface sensor testing complete
• Bottle being overwrapped this week (4/27)
• Final burst tests planned for June 2012 at WSTF
31
Coupon testing
Analysis and Modeling
Theoretical development
Embedding / Fabrication
Sensor Installation
Failure Testing
KSC: Magnetic Stress Gages (MSGs)
Project Objectives
• Design and demonstrate the ability of NDE sensors to measure stresses on the inner diameter of a COPV overwrap.
• Results will be correlated with other NDE technologies such as acoustic emission (AE)
• Project will build upon a proof-of-concept study performed at KSC which demonstrated the ability of MSGs to measure stresses at internal overwraps and upon current AE research being performed at WSTF
• Ultimate goal is to utilize this technology as a key element of health monitoring under the “Smart COPV” Program– Applicable to essentially all future flight programs
32
KSC: Proof of Concept Hydrostatic Test
• Full COPV tested hydrostatically at KSC on February 5, 2011• Vessel cycled to 8,000 psi and back to zero stopping at 2,000 psi increments
– Pressure chosen to mimic MEOP – Estimated design burst pressure of COPV is 16,000 psi
• Based on coupon tests 3 sensor configurations were chosen– Different wavelength to obtain various depth of penetration
• Tests were performed with 3 sensor orientations– 90º, 60º and 17º to align sensor drive with fiber orientations
33
Backup Slides
34
35
Example AE Results
S/N 82 FAILURE.xls 21 December 2006
0
200
400
600
800
1000
1200
1400
1600
1800
52000 53000 54000 55000 56000 57000 58000 59000 60000
Time (sec)
Nu
mb
er
of
AE
Ev
en
ts RUPTURE TIME: 91 hrs
ADVANCE NOTICE: 1.98 hrs
AE indications begin to accumulate well before rupture occurs. The synchronization of these data to strain and temperature indications will be accomplished in the next phase of our project
~2 events / hour
~6 events / hour
Final Week of COPV Test Before Rupture
36
Felicity ratio (FR)
37
• Felicity ratio (FR) coupled with AE feature analysis, especially peak frequency and energy, shows promise as analytical pass/fail criteria
38
Results & Discussion
Pressure & Events vs. Time 0 to 17500 s 17500 to 37500 s (cont.)
Eve
nt
No
. (fi
lter
ed d
ata)
Eve
nt
No
. (fi
lter
ed d
ata)
A 6.3-in. diameter IM-7 COPV was subjected to an ILH pressure schedule at LR ≈ 0.3 to 0.9
LR = 0.89
Potential Pass/Fail CriteriaLower load hold AE indicative of severe
accumulated damage
AE due to significant composite damage below autofrettage P
38same testcontinued
Example COPV Test
Felicity ratio results for an IM7 composite overwrapped pressure vessel pressurized to 6800 psi and then to burst at 7870 psi
39
Potential Pass/Fail CriteriaFR < 1; The true limit is structurally dependant (0.95-0.99).
40
Results & Discussion
FFT (unfiltered) showing concerted failure using De Groot’s frequency ranges
fiber breakage
pull-out
ma
trix
cra
ckin
g
de
bo
nd
ing
41
Technique DevelopmentCarbon Stress Rupture Test System
4120 Carbon Vessels and real-time NDE in WSTF Lexan protective enclosure allows inspection while at test pressure
Conventional strain gauges installed near fiber Bragg gratings, relative to laser profilometry map
42
Inspection Challenges
COPVs used on ISS, the Orion Crew/Service Modules, and most other exploration spacecraft potentially need inspection under various scenarios, but they are often inaccessible – If it can be implemented, monitoring may address most needs – The concept of snakes/endoscopic NDE may help if provisions are made for
in-space inspection or ports can be made• Explore micro-meteoroid & orbital debris (MMOD) strike site and through to COPV
surface if structure is penetrated• Must be qualified to work in a space environment if used for EVA
– Imaging of composite through the metal structure and insulation may help if adequate sensitivity is demonstrated
Nitrogen Tank Assembly
43
Plasma Contactor Unit
44
45
AMS
Space DRUMS
ISS Payloads, Experiments, Systems
Six GBUs in Kibo
46
SAFER
SAFER (9”Lx6.6”D)
Contributing Information
• 4th IAASS Conference - Making Safety Matter , Nondestructive Evaluation and Monitoring Results from COPV Accelerated Stress Rupture Testing, NASA White Sands Test Facility (WSTF) (No. 1878627)
• Use of Modal Acoustic Emission to Monitor Damage Progression in Carbon Fiber/Epoxy Tows and Implications for Composite Structures, ASNT Fall Conference & Quality Testing Show, NASA NDE II Houston, TX
• New ASTM Standards for Nondestructive Testing of Aerospace Composites, ASNT Fall Conference & Quality Testing Show, NASA NDE II Houston, TX Jess M. Waller and Regor L. Saulsberry NASA-JSC White Sands Test Facility 48th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference,AIAA-2007-2324 , Overview: Nondestructive Methods and Special Test Instrumentation Supporting NASA Composite Overwrapped Pressure Vessel (COPV) Assessments
• NDE Methods for Certification and Production/Performance Monitoring of Composite Tanks, David McColskey, Marvin Hamstad, Regor Saulsberry, Jess Waller
• Shearography NDE of Composite Over-Wrapped Pressure Vessels (COPVs), ASNT Fall Conference 2007Survey of Nondestructive Methods Supporting Shuttle and ISS Composite Overwrapped Pressure Vessel (COPV) Testing, Aging Aircraft Conference , 2006
47
Contributing Information
• G.P. Sutton & O. Biblarz, Rocket Propulsion Elements, 7th Ed., John Wiley & Sons, Inc., New York, 2001, ISBN 0-471-32642-9. 2. D.K. Huzel & D.H. Huang, Modern Engineering for Design of Liquid-Propellant Rocket Engines, Vol 147, Progress in Astronautics and Aeronautics, Published by AIAA, Washington DC., 1992, ISBN 1-56347-013-6. 3. V. Yang, T. B. Brill, W.-Z. Ren, Solid Propellant Chemistry, Combustion, and Motor Interior Ballistics, Published by AIAA, Washington DC, 2000, ISBN 1-56347-442-5 4. F.-K. Chang, ed., Structural Health Monitoring 2005, DEStech Publications, 2005, ISBN 1-932078-51-7
48
Relevant Literature (non-inclusive list)
1. AIAA– S-080 Space Systems - Metallic Pressure Vessels, Pressurized Structures, and Pressure Components– S-081A Space Systems - Composite Overwrapped Pressure Vessels (COPVs)
2. ASME– STP-PT-021 Non Destructive Testing and Evaluation Methods for Composite Hydrogen Tanks
3. ASTM– E 1419 Test Method for Examination of Seamless, Gas-Filled, Pressure Vessels Using Acoustic Emission– E 1736 Practice for Acousto-Ultrasonic Assessment of Filament-Wound Pressure Vessels– E 2191 Test Method for Examination of Gas-Filled Filament-Wound Composite Pressure Vessels Using
Acoustic Emission– E 2581 Practice for Shearography of Polymer Matrix Composites, Sandwich Core Materials and Filament-
Wound Pressure Vessels in Aerospace Applications
4. ISO– 14623 Space Systems - Pressure Vessels and Pressurized Structures - Design and Operation (similar to
AIAA S-080 and -081, and NASA-STD-5009)
5. NASA– MSFC-RQMT-3479 Fracture Control Requirements for Composite and Bonded Vehicle and Payload
Structures– NASA-STD-5007 General Fracture Control Requirements for Manned Spaceflight Systems– NASA-STD-5009 Nondestructive Evaluation Requirements For Fracture Control Programs
• JSC Special Addendum Physical Crack Standard– NASA-STD-5019 Fracture Control Requirements for Spaceflight Hardware– NASA-STG-5014 Nondestructive Evaluation (NDE) Implementation Handbook for Fracture Control
Programs (draft)
6. Miscellaneous– AFSPCMAN 91-710– CSA NGV2-2000 Basic Requirements for Compressed Natural Gas Vehicle (NGV) Fuel Containers– KHB 1710.2D– MIL-STD-1522 Standard General Requirements for Safe Design and Operation of Pressurized Missile
and Space Systems 49
Background – ASTM E07.10 TG of NDE of Aerospace Composites
• In late 2004, NASA took the lead in initiating efforts to develop national voluntary consensus standards for NDE of aerospace composite materials, components and structures
• ASTM Task Group (TG) for NDE of Aerospace Composites formed in January 2005 (under ASTM E07.10)
• The TG has been meeting twice a year since formation:– currently comprised of 116 members– chaired by George Matzkanin from TRI/Austin– other principals include Jess Waller and Regor Saulsberry, NASA-JSC White
Sands Test Facility; and Tom Yolken, TRI/Austin
• Initial focus was on polymer matrix composite material with relatively simple geometries such as flat panel laminates
• Current focus is on composite components with more complex inspection geometries, specifically COPVs– metallic liner (WK 29068)– composite overwrap (WK 29034)– liner/overwrap interface– Guide (TBD) 50
Background – ASTM Standards Developed Since 2005 and Current Plan
51
NDE of Flat Panel Composite Standard Practices and Guide
NDE of COPV Standard Practices, Feasibility of NDE of COPV Guide
2005
2010
2011
2012
2013
5-year re-approvalof E2580, E2580 and E2581
52
53
PRCS Thruster Injector Crack NDE
55
Composite Thickness Measurement
Eddy Current System for Real-time COPV Composite Thickness
56
Pre Burst NDE
Epoxy run
Black spots are bad pixels from
imager
Void Indications
Thermography Image