A theory for strain-based structural system identification

A theory for structural system identification which utilizes strains and translational displacements as measured outputs is presented. The state variables of the fundamental first-order form consist of the strains and the elemental or substructural rigid-body motion amplitudes. The theory is applicable to, and to some respects, motivated by the advances and expanded use of embedded piezoelectric sensors and fiber optics. A distinct feature of the present theory is its ability to provide rotational flexibility without having to measure rotational quantities. The theory is illustrated by simple ideal examples.