Book Description

An experimental and analytical program was conducted to investigate the longitudinal vibration properties of a two-stage full-scale launch vehicle loaded with various amounts of simulated propellants. A two-dimensional finite-element mathematical model formulated from vehicle physical parameters and experimental results was the basis for free-and forced-vibration analyses. Good agreement was obtained between the measured and predicted responses. Vector-response plots enhanced the interpretation of experimental and forced-vibration analytical results. Proper identification and correlation of the modes required a knowledge of the accelerations along the length of the vehicle, accelerations of specific components such as the engines and the turbopump, and pressures at the top and bottom of the propellant tanks.