Improvements in the estimation of b value: Limits of the power law

Abstract

The mechanical health of any composite specimen can be monitored by recording the acoustic emissions (AE) from the surface and hence can be used to predict mechanical fracturing of the material. The AE technique, which is a nondestructive and noninvasive technique, is a common method to monitor the mechanical health of a structure/material. The AE data emanated from a specimen under mechanical stress appears to follow power law distribution that can be used to estimate the power exponent (b value). It has been observed that empirical data do not completely follow power law, which in turn makes the estimation to be significantly erroneous. Some attempts have been made by the researchers in the past to filter out the non‐power law parts of the dataset; however, issues such as choice of upper and lower bounds and fixed values of these bounds for different types of datasets remain a challenge for efficient and robust estimation of b value. In the presented work, an attempt has been made to rectify the inherent shortcomings of b value and improved b value (ib value) estimation methodology. The proposed method, which is computationally light to implement, has been verified on some synthetic and experimental datasets. The results show promising improvements in the estimation of b value parameter from the previous reported methods in the literature.