Numerical and experimental studies on vibration-based damage detection methods in beam structures

Abstract

Vibration-based damage detection (VBDD) methods have emerged as powerful, cost-effective, and non-destructive methods for detecting and assessing damage in structures. These methods utilize the natural dynamics of structures to identify the presence, location, and extent of damage. Analyzing changes in modal parameters such as natural frequencies, mode shapes, and modal curvatures can detect structural anomalies that indicate damage. This paper describes the flexibility matrix method, the modal curvature method, and the gaped smoothing methods and proposes a new method called the square of modal curvature method. Initially, these damage detection methods are studied using a numerical model of a simply supported beam. The results indicate that the square of modal curvature (SMC) method can effectively detect damage using only a few low-frequency modes. The proposed SMC method is further tested using experimental data obtained from a free-free beam model. Two cases are considered: one with experimental vibration data from an intact beam, and the other without. In the absence of data from an intact beam, the SMC method is combined with the Gapped Smoothing Method (GSM). Both test cases yield reliable results.

Keywords

• vibration based damage detection, measurement data, damage detection, modal curvature.