Solid rocket motor static fire test stand optimization : load cell effects and other uncertainties
Date of Award
Master of Science in Engineering (MSE)
Mechanical and Aerospace Engineering
Robert A. Frederick Jr.
Jason T. Cassibry
Rocket engines--Thrust., Hysteresis.
US military legacy missile systems must be periodically tested to ensure they will perform as designed during training and in times of armed conflict. The objective of this work was to assess the overall thrust measurement uncertainty of a tactical-sized solid rocket motor static thrust stand. Motor alignment, load cell / test stand dynamics, signal conditioning, data acquisition, and calibration procedures were examined as potential sources of uncertainty. The uncertainty analysis revealed that a 5,000 lbf thrust measurement can be made to within ±0.26% of full scale with 95% confidence. The load cell / test stand / motor structural resonance was the dominate source of thrust data distortion. Increasing load cell stiffness, increased the resonant response frequency out of the analysis band for the system investigated. Low hysteresis during in-situ load cell calibrations was determined to be an excellent measure of motor / test stand alignment. A properly selected / designed load cell was shown to eliminate most requirements to digitally manipulate or post-process thrust data, e.g., filtering or data averaging, and prevent the unintentional suppression of any real-world physical phenomena.
Freeman, Charles W. II, "Solid rocket motor static fire test stand optimization : load cell effects and other uncertainties" (2018). Theses. 263.