Sensitivity-based damage detection algorithm for structures using vibration data

Damage in a structure can lead to changes in the structural properties such as stiffness and natural frequencies. The ratio of frequency changes in two modes is a function of the damage location. In this paper, vibration data and static displacement measurements are used to detect and quantify structural damages. A sensitivity analysis is performed to study how natural frequencies and static displacements change in the presence of a structural damage. An objective function representing an error is defined using the sensitivity equation and minimized using Cuckoo Search algorithm. The effectiveness of the technique is demonstrated with the help of cantilever beams and fixed–fixed beam in which different damage scenarios are simulated using ANSYS and analyzed to obtain the modal parameters. In addition, a laboratory tested space frame model has been used to demonstrate the proposed technique. Numerical results indicate that damages can be accurately detected and quantified in a relatively shorter computational time using the Cuckoo Search algorithm.