Recent Developments on Structural Health Monitoring and Data Analyses

Abstract

The term “Structural Health Monitoring (SHM)” refers to continuous monitoring of a structure in order to track the changes in its dynamic characteristics and detect damage. In Civil/Structural Engineering, the majority of SHM applications are directed towards studying the response and damage from natural hazards, such as earthquakes and strong winds. The monitoring typically involves measuring continuously the vibrations of the structure by acceleration sensors. Some recent applications have also included GPS sensors, which provide superior accuracy for measuring displacements. Although a significant number of structures are now installed with SHM systems, the utilization of data for practical applications are still lacking. Some of the new findings resulting from SHM include the significant influence of environment on structural frequencies and damping, strong dependency of damping on amplitude and frequency, exponential decay in modal damping values with increasing building height, and the prevalence of 3D modes and non-proportional damping. A critical need in SHM is the simple tools and techniques for real-time data analysis and interpretation. Since data come continuously, the analysis cannot be done in batch mode; it should be done in real-time. This chapter summarizes the latest developments in SHM, with emphasis on data analysis and damage detection. The topics discussed include real-time analysis techniques, noise reduction in ambient vibration data, utilization of wave propagation approach as an alternative to spectral analysis, inadequacy of modal parameters for damage detection, applications of Seismic Interferometry for data analysis, and identification and damage detection for historical structures.