Modeling and Control of Magnetorheological Dampers

Modeling and Control of Magnetorheological Dampers
for Seismic Response Reduction
S.J. Dyke,1 B.F. Spencer Jr.,2 M.K. Sain3 and J.D. Carlson4
1Dept. of Civil Engrg., Washington University, St. Louis, MO 63130
2Dept. of Civil Engrg. and Geo. Sci., Univ. of Notre Dame, Notre Dame, IN 46556
3Dept. of Electrical Engrg., Univ. of Notre Dame, Notre Dame, IN 46556
4Mechanical Products Division, Lord Corporation, Cary, NC 27511
Abstract
Control of civil engineering structures for earthquake hazard mitigation represents a relatively
new area of research that is growing rapidly. Control systems for these structures have unique
requirements and constraints. For example, during a severe seismic event, the external power to a
structure may be severed, rendering control schemes relying on large external power supplies ineffective.
Magnetorheological (MR) dampers are a new class of devices that mesh well with the
requirements and constraints of seismic applications, including having very low power requirements.
This paper proposes a clipped-optimal control strategy based on acceleration feedback for
controlling MR dampers to reduce structural responses due to seismic loads. A numerical example,
employing a newly developed model that accurately portrays the salient characteristics of the
MR dampers, is presented to illustrate the effectiveness of the approach.