Global–Local Damage Diagnostic Approach for Large Civil Structures with Very Limited Sensors.

It is important but still challenging to detect structural damage with limited instrumentation in the spatially large civil infrastructure. In this paper, a damage detection algorithm is proposed employing a global–local approach with limited sensors for detecting structural damage of spatially large civil <italic>engineering</italic> structures. The proposed algorithm is based on measuring frequency response functions (FRFs) at convenient yet selective locations on the structure with very limited sensors to localize the region of damage in the structure using the proposed global diagnostic approach. Once the local region of damage is established, local diagnostics are performed in the isolated small region of the structure using high fidelity sensing, still, a limited number of sensors in the small localized region (segment) of the structure, to precisely locate the damage. The principal component analysis combined with fractal dimension theory is employed for local diagnostics. Numerical studies have been conducted on a 6m simply supported beam and a 30-storey framed structure idealized as a shear building. Experimental verification of the proposed global–local damage diagnostic approach is also carried out. Studies presented in this paper indicate that the global–local approach for damage diagnosis of spatially large structures is very promising for precisely locating the damage with very limited sensors. [ABSTRACT FROM AUTHOR]