at- faa / nasa workshop on key characteristics for composite material control cirrus design industry...
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AT-
FAA / NASA WORKSHOP ON KEY CHARACTERISTICS FOR
COMPOSITE MATERIAL CONTROL
Cirrus Design Industry ReviewAugust 6th, 2002
718/02
2FAA / NASA Workshop August 6th, 2002
OLD vs. NEW APPROACH
Develop Material Qualify MaterialProduce / Use
Material
DevelopMaterial
QualifyMaterial
Produce / UseMaterial
MonitorMaterial, SPCPeriodic
Property Testing
EvaluateMaterial Changes
CharacterizeMaterial
Property Database,Specifications
[Finite Project with a beginning and end]
[Continuous Project – live documents]
3FAA / NASA Workshop August 6th, 2002
PAST EXPERIENCE – 2 STAGES
MATERIAL QUALIFICATIONOverall positive experiences. Good support from co-workers, suppliers and FAA. Positive and optimistic attitudes. High level of confidence in material quality.
PRODUCTION AND QUALITY CONTROL Learned some lessons the hard way. Transitioned from small to large-scale prepreg production process.Introduced new players, test labs not involved in qualification. Qualification batches not totally representative of production material.Material and part fabrication challenges caused by lack of material and process control. Frustrations from suppliers due to inconsistent end requirements. Frustrations with suppliers due to lack of material and process control.
4FAA / NASA Workshop August 6th, 2002
CIRRUS POINT OF VIEW
Positive outlook on new approach: • Flexible and open to changes. • Low reliance on precedence.• “Common-sense” philosophy.
Agree with basic goals of workshop:• Standardize procurement, testing, & increase process control. • Give separate materials separate batch requirements.• Provide additional material monitoring and control throughout process – closed loop process.
• Shared technical information on critical material control issues.
5FAA / NASA Workshop August 6th, 2002
CIRRUS CONCERNS“Cost of manufacturing a composite structure often exceeds that of
an equivalent aluminum structure.”
New Approach Requires:
Additional time and expertise from all levels (suppliers, end-users, FAA). Upkeep of material database is time-consuming.
Increased resources drive up material costs.
End-user: QA/SPC need to understand structural implications of failures on a property-specific level.
Supplier: Proprietary issues required in the Process Control Doc.
Initial goal of general material database was to reduce redundant testing and bring down qualification costs. However, by increasing material control level, qualification and support costs will result.
BALANCE
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