Methodology for Predicting the Time-Dependant Properties of Polymer and Ceramic Matrix Composites Exposed to Extreme Temperatures for Short Durations

Polymer matrix composite (PMC) allowable operating temperatures are limited by the polymer’s glass transition temperature (Tg) and are assigned based on long term exposure, thermal cycling, 20,000 hour service life, and manned aero-vehicle requirements. Short- to medium-range tactical missiles are unmanned, are single-use, and have exposures and service lives of no more than a few minutes. PMCs retain significant strength in excess of their long term use strength when heating occurs over a very short duration. However, the behavior of composites in this transient regime is not well understood, thus, engineers typically design composites to long-term-use limitations, taking a substantial weight penalty. The VSC team proposes to develop and validate a progressive damage prediction model for composites (PMC and CMC) subject to thermal loads beyond the long term operating temperature for short durations. Preliminary development of the approach has already occurred under Raytheon funding by USC. ABAQUS finite element analysis software will be customized to account for progressive damage over short flight durations due to heating. Material characterization data will be gathered for two PMCs and one CMC. The data and modeling approach will be used to predict residual mechanical, thermal, and electrical properties. Testing will conducted to verify predictions. BENEFITS: The benefits of the proposed analysis model development and validation effort include: Availability of an analysis tool for designing with composites in the high temperature, short duration flight regime. Elimination of considerable “make and break” testing cycles reducing non-recurring cost and schedule. Allows efficient use of composites in short and medium range missile airframes Lighter weight, higher performance, increased range for short and medium range missiles.