A Brief History of 30 Years of Model Updating in Structural Dynamics

Since the development of the Finite Element (FE) method at the University of California Berkeley and the Boeing Company in the 1960s, the question of appropriateness of a model has always preoccupied developers and practicing engineers. Because of the early focus on predicting the linear vibrations of coupled systems for aerospace and civil engineering applications, test-analysis reconciliation initially consisted in updating the FE matrices such that their eigen-properties reproduce the identified resonant frequencies and mode shape vectors. As the FE method increased in sophistication in the following decades, and computational resources became widespread, test-analysis reconciliation evolved beyond optimal matrix updating to include sensitivity and residual-based methods that attempted to calibrate individual element matrices or design parameters. Fueled by an ever-increasing diversity of applications, FE model updating expanded beyond the correlation of modal response to handle frequency response functions, static deflections, and time-domain waveforms. Component mode synthesis concepts were progressively integrated to handle the spatial mismatch between measurement points of a structure and the FE discretization where the spatial information is predicted. This publication briefly overviews the first 30 years of FE model updating development, from the mid-1960s to the mid-1990s, because most of the technology currently available originates in this period. FE model updating methods are categorized into broad categories that each offer their own benefits and limitations. Potential growth areas, such as application to nonlinear dynamics, are discussed.