Crack detection in structures using deviation from normal distribution of measured vibration responses

• Direct use of time-domain vibration responses of structures with breathing cracks.
• Computing the deviation of measured responses from their normal distribution (DND).
• Using second derivative of DNDs for crack localisation in structures.

Cracks are one of the common defects in structural components that may ultimately lead to failure of structures if not detected. Generally, most of the vibration based crack detection methods transform measured vibration responses from time-domain into frequency-domain using Fourier or wavelet transform for damage detection. However, it would be more convenient if the vibration responses could be analysed in their original time-domain. Therefore, a practical method based on probability distribution function is proposed which performs all the data processing in time-domain for the purpose of crack detection in beam-like structures. The application of the proposed method to both numerical and experimental examples and their results are presented.