Vibration-based crack detection in cantilever beams using Rao-1 algorithm

Abstract

The prediction of crack location and crack depth in a cantilever beam is considered as an optimisation problem. In this paper, the location and depth of the crack are predicted by minimising the cost function. The cost or objective function is formulated based on the difference between the first three experimental and calculated natural frequencies. The natural frequencies are calculated from the equations which are developed based on the numerical analysis. Rao-1 algorithm is used for predicting the crack location and depth. The Rao-1 algorithm does not have any algorithm-specific parameters to tune them to get optimised performance. Results obtained from the Rao-1 algorithm are compared with those obtained by particle swarm optimisation (PSO). PSO algorithm detected the crack with an average error of 4.94% and the crack depth with 5.96% whereas the Rao-1 algorithm has predicted the location and depth of the crack with an average error of 4.85% and 6.08%. Rao-1 algorithm is also robust and can be used in damage detection to avoid tuning algorithmspecific parameters for better prediction.