Comparison of different excitation‐ and data sampling‐methods in structural health monitoring

Abstract

Structural Health Monitoring with analysis of dynamic characteristics intends to detect stiffness changes caused by damage. It can be performed by vibrational tests resulting to modal parameters, that is, eigenfrequencies, damping, modeshapes, or modal masses. Those parameters are themselves informational and even allow often deducing the stiffness matrix. Based on that, it is possible to identify and to localize changes in the stiffness matrix due to damage, that is, localization and quantification of damage. However, changing test conditions, like ambient temperature or excitation force or existing nonlinearities of concrete, show important influence on damage indicators and hence need compensation prior to damage detection. Considering this background, this article focuses on comparing ambient excitation to forced excitation including appropriate exciters. Furthermore, continuous monitoring is discussed vs discrete testing in distinct time-intervals. The intention of the comparison is to give an overview, that is, helpful for choosing appropriate measurement technique for the sake of correct damage detection subsequently. K E Y W O R D S ambient excitation, dynamic damage indicators, forced excitation, modal analysis, structural health monitoring

Machine learning and structural health monitoring overview with emerging technology and high-dimensional data source highlights

“…However, in exceptional cases and depending on the extent of the damage, it may be necessary to perform both excitation techniques in a combined approach. 46 Further advantages and disadvantages of these excitation methods can be found in Farrar et al 45 and Maas et al 47…”