Experimental Modal Analysis testing - a powerful tool for identifying the in-service condition of bridge structures

摘要

The Experimental Modal Analysis (EMA) testing technique provides a great deal more information about the in-service condition of a bridge under test than is possible from the more traditional forms of static testing through identification of the modal properties (natural frequencies, mode shapes and damping levels) of the bridge concerned. This information is of immense value to the "tuning" of Finite Element Method (FEM) based models which can then be used with confidence for assessing bridge load carrying capacity and response to seismic and other dynamic load inputs. This paper outlines some of the key features of the technique highlighting results obtained from its application to the field testing of several bridges by the University of Melbourne structural engineering research team.