In-test analytical model updating for accurate hybrid dynamic simulations

Abstract

Hybrid simulation is the most reliable assessment approach for structural systems too large for testing in laboratories. It combines the effectiveness of numerical modeling with the accuracy of experimental investigations by sub-dividing the structural system into a computer-simulated part and a physically tested part. The components that exhibit highly inelastic behavior are tested in the laboratory, while the remaining structural system is numerically modelled. Matching of actions and deformations at the boundaries between physical and numerical components takes place at each time interval during the dynamic hybrid simulation process.In many structural systems, there is an important feature that reduce the effectiveness, efficiency and/or accuracy of hybrid simulation; cases where either it is not possible to predict the critical elements of the structure that will cause failure, or if these critical members are too many to test at full scale. The concept of in-test analytical model updating for hybrid simulations addresses the aforementioned challenge. In the in-test model updating approach, only one component is experimentally investigated. During the test, experimental measurements are utilized to instantaneously update the governing parameters of the numerical model at each time-step. The numerical model therefore exhibits increased accuracy with every increment of the ongoing simulation.In this paper, an overview of in-test model updating in slow rate hybrid simulation is provided. It is followed by examples of different approaches for tuning the parameters of the numerical model based on the continuous acquisition of experimental measurements. Practical examples from the authors’ work and other researchers are presented and critiqued. General conclusions regarding the suitability of various model updating methods for different classes of dynamic testing of structural systems are presented.