Passive damping devices for aerospace structures

Aerospace structures are subjected to a variety of large dynamic excitations especially during launch and ascent into orbit, leading to high dynamic responses. In order to attenuate the dynamic responses it is possible to manipulate the mass matrix or the stiffness matrix or to introduce damping. This paper deals with passive damping devices which can be incorporated in the spacecraft structure in order to introduce significant damping. Four different damping principles will be discussed. These principles are based on the following physical effects: Shearing a viscous fluid in a small gap (hydrodynamic concept). Throttling (hydraulic concept). Coulomb friction. Energy dissipation by relaxation and recovery of elastomers (viscoelastic bushings). For these damping principles formulas and material data are presented in order to pre-design corresponding damper devices. For each damping device a design proposal will be given. In order to investigate the influence of elasticities within the damper on the damper performance, simulations with simplified mathematical models of the damping devices have been performed. (C) 2002 International Astronautical Federation. Published by Elsevier Science Ltd. All rights reserved.