System for stabilizing dimensional properties of cured composite structures
US4806292A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 21, 1986 |
| Grant date | Feb 21, 1989 |
| Priority date | — |
| Expiry date | Jan 21, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/02881
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Method and apparatus are disclosed for inducing dimensional stability in cured composite structures using acoustic emission analysis to identify the appropriate level and extent of coincident thermal conditioning. Temperature of the composite structure is lowered at a bounded rate to a minimum temperature typical of the intended operating environment. Passive stress wave acoustic emissions of the composite are analyzed to generate a signature of stress relaxation events over time. When the rate of stress relaxation events decreases below a predetermined percentage of the maximum rate, and remains below that level for a period of time sufficient to predict operational stability, thermal conditioning is terminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.