Gain-scheduled H ∞ buckling control of a circular beam-column subject to time-varying axial loads

• Published in: Smart materials and structures Vol. 27; no. 6
• Main Authors: Schaeffner, Maximilian, Platz, Roland
• Format: Journal Article
• Language: English
• Published: IOP Publishing 03.05.2018
• Subjects: buckling control; control; gain-scheduled; linear parameter-varying (LPV) system; time-varying axial load
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/1361-665X/aab63a

For slender beam-columns loaded by axial compressive forces, active buckling control provides a possibility to increase the maximum bearable axial load above that of a purely passive structure. In this paper, an approach for gain-scheduled H ∞ buckling control of a slender beam-column with circular cross-section subject to time-varying axial loads is investigated experimentally. Piezo-elastic supports with integrated piezoelectric stack actuators at the beam-column ends allow an active stabilization in arbitrary lateral directions. The axial loads on the beam-column influence its lateral dynamic behavior and, eventually, cause the beam-column to buckle. A reduced modal model of the beam-column subject to axial loads including the dynamics of the electrical components is set up and calibrated with experimental data. Particularly, the linear parameter-varying open-loop plant is used to design a model-based gain-scheduled H ∞ buckling control that is implemented in an experimental test setup. The beam-column is loaded by ramp- and step-shaped time-varying axial compressive loads that result in a lateral deformation of the beam-column due to imperfections, such as predeformation, eccentric loading or clamping moments. The lateral deformations and the maximum bearable loads of the beam-column are analyzed and compared for the beam-column with and without gain-scheduled H ∞ buckling control or, respectively, active and passive configuration. With the proposed gain-scheduled H ∞ buckling control it is possible to increase the maximum bearable load of the active beam-column by 19% for ramp-shaped axial loads and to significantly reduce the beam-column deformations for step-shaped axial loads compared to the passive structure.