A Generalized Optimal Sensor Placement Technique for Structural Health Monitoring and System Identification

A structural health monitoring system consists of permanently installed sensors to collect structural information, and these sensors are required to be placed at ‘good’ positions for damage identification. Conventional sensor placement methods make use of dynamic characteristics of a structure, i.e., mode shapes and natural frequencies, to determine optimal sensor positions. The engineering community has traditionally relied on these modal methods and finite element analysis for dynamic predictions in the low frequency range. However, these techniques become ineffective in mid frequency range due to large number of modes and high modal density. In view of this, in this paper, an optimal sensor placement technique which can be employed for low as well as mid frequency range structures for structural health monitoring as well as structural system identification is presented. The frequency domain based optimal sensor placement technique (FEfi) presented in this paper makes use of principal components evaluated from frequency response functions at the desired frequency levels. Numerical examples with optimally placed sensors dictated by the proposed algorithm are presented and compared with the popular effective independence (Efi) technique based on mode shapes.