On the analysis of antiresonance frequencies for structural damage localization

Abstract

During the service life of long-lasting constructions, structural changes occur that can lead to damage or failure. For reasons of economic and ecological sustainability, it is of great importance to detect these changes as early as possible to ensure safe operation and to be able to initiate maintenance measures if necessary. To detect and localize emerging damages, structural health monitoring systems can be employed. The realization of such systems requires methods that can derive information about the condition of the monitored object from measurement data. To develop a better understanding of how damage affects structural integrity, simulation models of generic structures can be used. In most cases, structural damage can be generalized as some type of local stiffness reduction, causing changes in the dynamic properties of the structure. From a numerical perspective, this means that the dynamic stiffness matrix of the system changes, which can lead to shifts in resonance and antiresonance frequencies. Since resonance frequencies are global characteristics of the structure, they may contain information about the occurrence of structural damage, but not about its location. Therefore, this paper investigates whether and how the observation of the antiresonance frequencies can be used to both detect and localize damages.