Improved Analytic Longitudinal Response Analysis for Axisymmetric Launch Vehicles. Volume 2: Computer Program Description
TRW SPACE TECHNOLOGY LABS REDONDO BEACH CA
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This program uses an improved linear analytical model for the calculation of launch vehicle steady- state response to applied sinusoidal loads acting in the longitudinal direction. The present approach utilizes a finite element technique to construct the total launch vehicle stiffness K and mass M characteristics by subdividing the prototype structure into a consistent set of 1 axisymmetric shell components a1 to represent as separate units the fairing, interstage structure, bulkhead, tank walls and engine thrust structure 2 fluid components b1 and 3 mass-spring components c1 to provide the inertial and stiffness characteristics of the equipment and engines and vehicle supporting structure. The total vehicle characteristics are obtained by superposition of the stiffness and inertial characteristics of the individual shell, fluid and mass- spring components which are computed using a generalized coordinate approach. Fluid force and inertial coupling between all structural components is accomplished by assuming fluid motions consistent with the shell component distortions. The superposition technique automatically assures displacement compatibility and satisfies force equilibrium at the joints between components. After the complete system matrix bas been formulated, displacement boundary conditions are introduced by removing appropriate rows and columns of matrix coefficients corresponding to points on the vehicle and its supports which are rigidly restrained from motion.
- Unmanned Spacecraft