Input-output decoupling and disturbance rejection problems in structural analysis

Abstract

In this paper the disturbance rejection and the input-output decoupling problems of civil engineering structures via state/output feedback are investigated. Here the civil engineering structures are considered to be assembled from finite elements obeying linear material laws, their displacements being small and the number of inputs (control forces) equaling the number of outputs (displacements). In this case it is proved that the decoupling problem always has a solution. However, neither disturbance rejection nor simultaneous disturbance rejection and decoupling can be achieved. Issues such as the general analytical expression for the controller, the general form of the diagonal elements of the decoupled closed-loop system and closed-loop properties, i.e. stability, pole assignment, cancelled-out poles, are also studied.