THERMO-CHEMICAL-STRUCTURAL ANALYSIS OF CARBON-PHENOLICS WITHPORE PRESSURE AND PYROLYSIS EFFECTS

CARBON-PHENOLIC (C/PH) COMPOSITES HAVE BEEN WIDELY USED IN SOLID ROCKET MOTORS DESPITE THE FACT THAT THEIR HIGH-TEMPERATURE, THERMOSTRUCTURAL BEHAVIOR IS NOT WELL UNDERSTOOD. MANY OF THE FAILURE MODES (E.G., WEDGE-OUT, PLY-LIFT, DELAMINATION, POCKETING) COMMONLY SEEN IN THE C/PHCOMPONENTS OF FIRED SRM NOZZLES CAN ONLY BE EXPLAINED AS PORE-PRESSURE-INDUCED PHENOMENA THAT OCCUR DURING PYROLYSIS. YET, CURRENT THERMOSTRUCTURAL ANALYSIS METHODS ARE INCAPABLE OF ACCURATELY PREDICTING THE HIGH HEATING RATE BEHAVIOR OF SIMPLE C/PH TEST SPECIMENS, LET ALONE ACCURATELY CHARACTERIZING THE PORE PRESSURE AND PYROLYSIS BEHAVIOR OF AN ACTUAL MOTOR NOZZLE. THIS PROJECT ADDRESSES THE PROBLEM OF ACCURATELY CHARACTERIZING THE THERMOSTRUCTURAL BEHAVIOR OF C/PH SUBJECTED TO A HIGH-TEMPERATURE AND HEATING-RATE ENVIRONMENT AS TYPICALLY FOUND IN A SOLID ROCKET MOTOR. THIS WILL BE ACCOMPLISHED BYUSING A VOLUME-BASED CONTINUITY MODEL TO COUPLE THE THERMO-CHEMICAL TO THE THERMOSTRUCTURAL ANALYSIS. THIS UNIQUE APPROACH MODELS THE PORE-PRESSURE DEVELOPMENT DURING PYROLYSIS MORE ACCURATELY THAN CURRENT ANALYTICAL METHODS SINCE IT COUPLES THE PORE-PRESSURE LEVEL DIRECTLY TO THE STRUCTURAL DEFORMATIONS. CARBON-PHENOLIC (C/PH) COMPOSITES HAVE BEEN WIDELY USED IN SOLID ROCKET MOTORS DESPITE THE FACT THAT THEIR HIGH-TEMPERATURE, THERMOSTRUCTURAL BEHAVIOR IS NOT WELL UNDERSTOOD. MANY OF THE FAILURE MODES (E.G., WEDGE-OUT, PLY-LIFT, DELAMINATION, POCKETING) COMMONLY SEEN IN THE C/PHCOMPONENTS OF FIRED SRM NOZZLES CAN ONLY BE EXPLAINED AS PORE-PRESSURE-INDUCED PHENOMENA THAT OCCUR DURING PYROLYSIS. YET, CURRENT THERMOSTRUCTURAL ANALYSIS METHODS ARE INCAPABLE OF ACCURATELY PREDICTING THE HIGH HEATING RATE BEHAVIOR OF SIMPLE C/PH TEST SPECIMENS, LET ALONE ACCURATELY CHARACTERIZING THE PORE PRESSURE AND PYROLYSIS BEHAVIOR OF AN ACTUAL MOTOR NOZZLE. THIS PROJECT ADDRESSES THE PROBLEM OF ACCURATELY CHARACTERIZING THE THERMOSTRUCTURAL BEHAVIOR OF C/PH SUBJECTED TO A HIGH-TEMPERATURE AND HEATING-RATE ENVIRONMENT AS TYPICALLY FOUND IN A SOLID ROCKET MOTOR. THIS WILL BE ACCOMPLISHED BYUSING A VOLUME-BASED CONTINUITY MODEL TO COUPLE THE THERMO-CHEMICAL TO THE THERMOSTRUCTURAL ANALYSIS. THIS UNIQUE APPROACH MODELS THE PORE-PRESSURE DEVELOPMENT DURING PYROLYSIS MORE ACCURATELY THAN CURRENT ANALYTICAL METHODS SINCE IT COUPLES THE PORE-PRESSURE LEVEL DIRECTLY TO THE STRUCTURAL DEFORMATIONS.