Fracture Mechanics and Service Life Prediction Research
Abstract
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 program's 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.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- September 1999
- Bibcode:
- 1999STIN...0315828L
- Keywords:
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- Fracture Mechanics;
- Mathematical Models;
- Service Life;
- Solid Propellant Rocket Engines;
- Crack Propagation;
- Adhesives;
- Crack Tips;
- Spacecraft Reliability;
- Cost Reduction;
- Joints (Junctions);
- Spacecraft Propulsion and Power