OPTIMIZATION OF PASSIVE AND ACTIVE NONLINEAR VIBRATION MOUNTING SYSTEMS BASED ON VIBRATORY POWER TRANSMISSION

While significant non-linear behavior has been observed, in many vibra tion mounting applications, most design studies are typically based on the concept of linear system theory in terms of force or motion trans missibility. In this paper, an improved analytical strategy is present ed for the design optimization of complex, active or passive, non-line ar mounting systems. This strategy is built upon the computational Gal erkin method of weighted residuals, and incorporates order reduction a nd numerical continuation In an iterative optimization scheme. The ove rall dynamic characteristics of the mounting system are considered and vibratory power transmission is minimized via adjustment of mount par ameters by using both passive and active means. The method is first ap plied through a computational example case to the optimization of basi c passive and active, non-linear isolation configurations. It is found that either active control or intentionally introduced non-linearity can improve the mount's performance; but a combination of both produce s the greatest benefit. Next, a novel experimental, active,:non-linear isolation system is studied. The effects of non-linearity on vibrator y power transmission and active control are assessed via experimental measurements and the enhanced Galerkin method. Results show how harmon ic excitation can result in multiharmonic vibratory power transmission . The proposed optimization strategy offers designers some flexibility in utilizing both passive and active means in combination with linear and non-linear components for improved vibration mounts. (C) 1996 Aca demic Press Limited