Structural Crack Identification Method Based On Dynamic Distributed Strain Monitoring

摘要

Due to the factors such as environment, material aging, and fatigue loads, structural members are prone to crack damage during the service, which could lead to the risk of collapse as the crack-induced strain accumulates. This paper proposes a method for structural crack identification and location based on a distributed optical fiber dynamic strain monitoring method. The Savitzky-Golay smooth filtering method was used to extract the crack information from the obtained dynamic strain signal. Based on the local strain anomaly of the structure and the nonlinear vibration characteristics of the "breathing" crack model, the cracks distributed along the structure can be located. According to the change of harmonic component, the crack development process can be identified, and early identification and localization of structural cracks during operation can be realized, which provides a practical approach of the damage monitoring for the cracked structures.