Finite element model updating and damage detection using artificial boundary conditions

Abstract

An experimental test of a structure results in a database of frequency response functions from which natural frequencies and mode shapes are identified for the given boundary conditions of the test. The natural frequencies of a system under a variety of boundary conditions can be identified by applying artificial boundary conditions (ABCs) at measurement locations and obtaining the frequency response function for the unrestrained degrees of freedom. These frequencies are found without any physical alterations of the test boundary conditions. Use of the ABCs in sensitivity-based model updating and damage detection in conjunction with baseline data provides improved error localization and results in a more accurate finite element model.