Enhanced damping of lightweight structures by semi-active joints |
| |
Authors: | Lothar Gaul S Hurlebaus J Wirnitzer H Albrecht |
| |
Affiliation: | (1) Institute of Applied and Experimental Mechanics, University of Stuttgart, Pfaffenwaldring 9, 70550 Stuttgart, Germany;(2) Zachry Department of Civil Engineering, Texas A&M University, College Station, USA;(3) Daimler AG, Stuttgart, Germany;(4) Robert Bosch GmbH, Waiblingen, Germany |
| |
Abstract: | Summary Lightweight structures typically have low inherent structural damping. Effective vibration suppression is required, for example,
in certain applications involving precision positioning. The present approach is based on friction damping in semi-active
joints which allow relative sliding between the connected parts. The energy dissipation due to interfacial slip in the friction
joints can be controlled by varying the normal pressure in the contact area using a piezo-stack actuator. This paper focuses
on the optimal placement of semi-active joints for vibration suppression. The proposed method uses optimality criteria for
actuator and sensor locations based on eigenvalues of the controllability and observability gramians. Optimal sensor/actuator
placement is stated as a nonlinear multicriteria optimization problem with discrete variables and is solved by a stochastic
search algorithm. At optimal locations, conventional rigid connections of a large truss structure are replaced by semi-active
friction joints. Two different concepts for the control of the normal forces in the friction interfaces are implemented. In
the first approach, each semi-active joint has its own local feedback controller, whereas the second concept uses a global,
clipped-optimal controller. Simulation results for a 10-bay truss structure show the potential of the proposed semi-active
concept.
Dedicated to Professor Franz Ziegler on the occasion of his 70th birthday |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|