Fracture Mechanics and Service Life Prediction Research
Technical paper rept.
AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST
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The main issues in service life prediction of solid rocket motors are the lack of a fundamental understanding of crack growth behavior under service loading conditions and a reliable methodology to predict crack growth. It is relatively unknown in the areas of microstructure effects on damage initiation and evolution, large deformation effect on crack growth, and the effects of mismatch of material properties of a bond system on the stress fields near the interfacial crack tip. This program consists of five major tasks Task I predicting the initial crack length in high stress regions Task II - crack instability and growth models Task III - numerical modeling of crack growth and Task IV - interfacial fracture of bimaterial bond systems. The programs basic approach involves a blend of analytical and experimental studies. In general, mechanisms and mechanics involved in cohesive fracture in a solid propellant and adhesive fracture in bond systems are emphasized. Program results will provide a basis for developing advanced crack growth and service life prediction technologies for predicting the service life of solid rocket motors. The implementation of these advanced technologies will not only increase the reliability of the solid rocket motors but also significantly reduce the motor replacement costs.
- Rocket Engines