ABSTRACT
Each type of control considered in this monograph requires an appropriate object model with its associated components. Chapter 3 is devoted to this subject and it shows how to build models of a single wall, single-panel or double-panel one, as well as an entire casing. In this general case, a number of interacting subsystems are specified, as control of one panel causes vibrations of the medium between the panels and thus of the other panel in a two-panel arrangement, of the medium filling the casing and thus of the incident panels of the other walls, vibrations of a panel in a flexible casing cause changes in its boundary conditions and thus changes in the boundary conditions of the adjacent panels. The relationship between vibration and acoustic emission, the effect of the medium outside the casing on the outer panels and the interactions can also be considered.
Various modelling approaches are used, including a modal approach and a state-space description. Controllability and observability problems, important for appropriate arrangement of actuators and sensors, are referred to. The developed theoretical models are verified by simulation using multiphysics packages and experimentally in laboratory tests using the casing designs described above.
