Design of springs with negative stiffness to improve vehicle driver vibration isolation

Minimization of the fundamental frequencies of a vibratory system by means of springs with negative stiffness is probably the only way to attain infra-frequency vibration isolation under gravitation. Traditionally, the design of similar springs for vehicle driver vibration isolation systems was an art, and design decisions were based primarily on the designer experience. This paper presents an approach, based on the consistent theory of thin shells, for designing compact springs in terms of their compatibility with the room available for packaging the vehicle suspensions and simultaneous extension of the height control reizion where fundamental frequencies are kept minimal. In the approach, a generic model of a simple springing element with negative stiffness in the large is proposed. A simple iterative procedure is formulated to solve the geometricaliv nonlinear problem of large-amplitude post-bucking of springing elements and to represent them in a way that enables an optimal, computable scheme for the design of springs. Validity of the approach is assessed by a comparison of the computation and measurement results. Using the approach, we propose a generic spring module applicable to any vehicle suspension.. whether it is a seat suspension, a cab mounting, or a cargotainer platform. (c) 2007 Elsevier Ltd. All rights reserved.