Damage Identification for Underground Structure Based on Frequency Response Function

Abstract

Damage identification that is based on modal analysis is widely used in traditional structural damage identification. However, modal analysis is difficult in high damping structures and modal concentrated structures. Unlike approaches based on modal analysis, damage identification based on the frequency response function allows for the avoidance of error and easy verification through other test points. An updating algorithm is devised is this study by utilizing the frequency response function together with the dynamic reduction with respect to the selected design parameters. Numerical results indicate that the method can be used to define multiple parameters with large variation and incomplete measurement data and is robust against measurement noise. With the purpose of avoiding the occurrence of resonance and gaining additional information, the trial and error method has been used to choose a proper frequency. Furthermore, an experimental scale model in a soil box is subjected to the excitation of moving load to validate the effectiveness of the damage identification approach. The improved damage identification method for underground structures, which is based on the analysis of the frequency response function, can be adopted as an efficient and functional damage identification tool.

Bridge Damage Identification Using Vehicle Bump Based on Additional Virtual Masses

“…The damping of vehicle tire c3(t) is assumed to change with time as in Equation 16, where t3 is the moment of the largest deformation of the vehicle spring: Trial and iteration are required to determine t3 and c3(t). The main steps are described as follows: first, given an initial large value of t3, c3(t) is determined via Equation (16). Second, the vibration of the vehicle in Figure 6 during time period [t2, t3] is computed by integrating Equation (17) with the initial velocity v0 and the initial state xb of the bridge.…”

“…Structural dynamic characteristics are often used to detect damage by assessing their changes between an intact structure and a damaged structure. Structural modal parameters, such as natural frequencies, mode shapes, modal mass and stiffness, are popular as dynamic indices for damage identification [16][17][18][19], and are easily obtained due to the rapid development of experiment modal analysis techniques. For example, Wang et al [20] extracted the fundamental frequency of a bridge from the responses of an ordinary vehicle with its parameters calibrated in advance.…”

Numerical and Experimental Verification of a Multiple-Variable Spatiotemporal Regression Model for Grout Defect Identification in a Precast Structure

“…Several studies have focused on damage identification based on structural global responses. Based on natural frequency responses, Sha et al [10][11][12] carried out damage detection in beams, aluminum samples, and a soil box according to numerical simulations and experiments. The results demonstrated the capability of the methods to localize damage and to estimate the damage severity.…”

Wavelet Packet Singular Entropy-Based Method for Damage Identification in Curved Continuous Girder Bridges under Seismic Excitations

“…However, there is as yet a lack of advanced damage identification methods matched with such advanced sensing technologies. Existing SHM based damage detection methods employ dynamic characteristics such as natural frequencies [13,14,15,16,17], mode shapes [18,19,20,21], modal curvatures [22,23,24,25], and wavelet transform coefficients [26,27,28], to establish damage features. Among those methods, wavelet transform based diagnosis of damage has been adopted extensively with advantages in the time-frequency and multi-resolution analysis of measured dynamic responses of structures.…”