A simplified design procedure for life prediction of rocket thrust chambersAn analytical procedure for predicting thrust chamber life is developed. The hot-gas-wall ligaments separating the coolant and combustion gas are subjected to pressure loading and severe thermal cycling. The resulting stresses interact during plastic straining causing incremental bulging of the ligaments during each firing cycle. This mechanism of plastic ratcheting is analyzed and a method using a yield surface for combined bending and membrane loading developed for determining the incremental permanent deflection and progressive thinning near the center of the ligaments. Fatigue and tensile instability are analyzed as possible failure modes. Results of the simplified analyses compare favorably with available experimental data and finite element analysis results for OFHC (Oxygen Free High Conductivity) copper. They are also in reasonably good agreement with experimental data for NARloy Z, a copper-zirconium-silver alloy developed by the Rocketdyne Division of Rockwell International.
Document ID
19820051552
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Porowski, J. S. (O'Donnell and Associates, Inc. Pittsburgh, PA, United States)
Odonnell, W. J. (O'Donnell and Associates, Inc. Pittsburgh, PA, United States)
Badlani, M. L. (O'Donnell and Associates, Inc. Pittsburgh, PA, United States)
Kasraie, B. (O'Donnell and Associates, Inc. Pittsburgh, PA, United States)
Kasper, H. J. (NASA Lewis Research Center Cleveland, OH, United States)