A rational approach to the problem of accelerated testing for material characterization of advanced polymer matrix composites is discussed. The experimental and analytical methods provided should be viewed as a set of tools useful in the screening of material systems for long-term engineering properties in aerospace applications. Consideration is given to long-term exposure in extreme environments that include elevated temperature, reduced temperature, moisture, oxygen, and mechanical load. Analytical formulations useful for predictive models that are based on the principles of time-based superposition are presented. The need for reproducible mechanisms, indicator properties, and real-time data are outlined as well as the methodologies for determining specific aging mechanisms.Gates, Thomas S.Langley Research CenterPOLYMER MATRIX COMPOSITES; ACCELERATED LIFE TESTS; MICROSTRUCTURE; LIFE (DURABILITY); AGING (MATERIALS); MECHANICAL PROPERTIES; AEROSPACE ENGINEERING; AEROSPACE ENVIRONMENTS; RELIABILITY ANALYSIS; PERFORMANCE PREDICTION...