Damage Identification in Composite Beam by Vibration Measurement and Fuzzy Inference System

Abstract A significant efforts have been done by scientists and researchers in the last few years to develop many non-destructive techniques for damage recognition in a beam like dynamic structures. In this paper, theoretical, numerical, fuzzy logic methods employed for diagnosis of damage in the form of cracks of the cantilever composite beam with an aim to detect, quantify, and determine its intensity and locations. The Glass fiber reinforced epoxy composite engaged in the analysis due to high strength and stiffness-to-weight ratios. The theoretical analysis is performed to get the relationship between change in natural frequencies and mode shapes for the cracked and noncracked composite beam. The Numerical analysis is performed on the cracked composite beam to get the vibration parameters such as natural frequency and mode shape, which is used to design fuzzy logic, based smart artificial intelligent technique for predicting crack severity and its intensity. Online fuzzy based smart technique has been developed, first three natural frequencies and mode shapes used as input parameters, Gaussian membership functions is considered to detect cracks location and depth. The results of theoretical and numerical analysis are compared with experimental results having good agreement with the results predicted by the fuzzy inference system.