COST-EFFECTIVENESS IN ACTIVE STRUCTURAL CONTROL

The cost-effectiveness of active control of structural systems for pro tection against seismic hazards is examined. Considerations include un certainties in the earthquake occurrence and intensity, damage reducti on vs control actuator capacity, linear vs nonlinear structural behavi or, structural exposure time, discount of cost of future structural fa ilure in present dollar value, and cost of maintenance of control devi ces. Parametric studies of the expected life cycle cost of structures under seismic loads with and without the control device are carried ou t and compared for linear systems. The effectiveness of the control is also investigated when the excitation level is high and the structure becomes inelastic, The results show that the effectiveness drops sign ificantly, Expensive, large capacity control devices are generally not cost-justifiable. (C) 1997 Elsevier Science Ltd.