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James webb space telescope (jwst) integrated science instruments module (isim) electronics compartment (iec) conformal shields composite bond structure qualification test method
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Yew, Calinda Stephens, Matt |
| Copyright Year | 2015 |
| Description | The JWST IEC conformal shields are mounted onto a composite frame structure that must undergo qualification testing to satisfy mission assurance requirements. The composite frame segments are bonded together at the joints using epoxy, EA 9394. The development of a test method to verify the integrity of the bonded structure at its operating environment introduces challenges in terms of requirements definition and the attainment of success criteria. Even though protoflight thermal requirements were not achieved, the first attempt in exposing the structure to cryogenic operating conditions in a thermal vacuum environment resulted in approximately 1 bonded joints failure during mechanical pull tests performed at 1.25 times the flight loads. Failure analysis concluded that the failure mode was due to adhesive cracks that formed and propagated along stress concentrated fillets as a result of poor bond squeeze-out control during fabrication. Bond repairs were made and the structures successfully re-tested with an improved LN2 immersion test method to achieve protoflight thermal requirements. |
| File Size | 3186486 |
| Page Count | 21 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20150017739 |
| Archival Resource Key | ark:/13960/t8ff8s960 |
| Language | English |
| Publisher Date | 2015-09-01 |
| Access Restriction | Open |
| Subject Keyword | Thermal Vacuum Testing Chamber James Webb Space Telescope Thermal Vacuum Tests Epoxy Resins Failure Analysis Failure Modes Bonded Joints Reliability Analysis Shielding Composite Structures Cryogenic Temperature Operating Temperature Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Presentation |
