Damage assessment in a cracked fiber-reinforced cantilever beam using wavelet-kurtosis techniques

In the last decades the use of composite materials has increased especially in light-weight structural applications, such as wind turbine blades. These structural components require reliable methods for damage assessment to avoid progressive or sudden and catastrophic failures. In this paper, a model of a fiber-reinforced composite cantilever beam with a bridged edge crack, representing an existing damage state, is considered. The composite matrix of the beam exhibits a linear-elastic behavior, whereas a fracture mechanics-based theoretical model incorporating the crack bridging forces in the fiber-reinforcement is used to describe the elastic-plastic response of the cracked beam section subjected to bending moment. This model is employed to simulate the nonlinear static deflection of cantilever beams with different crack locations and depths. Wavelet-and kurtosis-based identification techniques are employed in the localization and calibration of this damage in presence of noise. The influence of the bridging effect of the fibers on the success of the damage assessment is discussed.