Damage Detection of Beam Structure Using Frequency Response Functions

The global dynamic behavior of structure can affect by the Presence of damage. Hence detection and quantification of damage has a greater significance in the context of structural health monitoring. This paper is based on frequency response function for detecting the presence and severity of damage in the structure. The variations in frequency response function is taken as a feature to detect damage. The different damage severities and the various damage locations change the amplitudes, shift peaks and alter shapes of the Frequency Response Functions (FRFs). The severity of the damage is quantified through severity index developed based on Frequency domain assurance criterion (FDAC).The major advantage of the proposed technique is that frequency response function can be measured easily through experiments. Numerical simulation studies have been carried out using a cantilever beam with varied damage cases. The damage is simulated through reduction in stiffness of a single or multiple element of finite element beam model considered. The investigation carried out in this paper clearly indicate that the technique based on FRF is effective for damage identification and quantification.