On the Potential of Dynamic Substructuring Methods for Model Updating

TL;DR

This paper explores the use of dynamic substructuring methods, specifically Craig Bampton techniques, to efficiently update finite element models for damage detection and quantification in structural health monitoring, demonstrated on a wind turbine tower.

Contribution

It introduces a comparison of Craig Bampton and Dual Craig Bampton reduced models within a Bayesian damage localization framework for wind turbine structures.

Findings

Reduced models enable efficient damage localization.

Craig Bampton and Dual Craig Bampton methods show comparable performance.

Model updating improves damage assessment accuracy.

Abstract

While purely data-driven assessment is feasible for the first levels of the Structural Health Monitoring (SHM) process, namely damage detection and arguably damage localization, this does not hold true for more advanced processes. The tasks of damage quantification and eventually residual life prognosis are invariably linked to availability of a representation of the system, which bears physical connotation. In this context, it is often desirable to assimilate data and models, into what is often termed a digital twin of the monitored system. One common take to such an end lies in exploitation of structural mechanics models, relying on use of Finite Element approximations. proper updating of these models, and their incorporation in an inverse problem setting may allow for damage quantification and localization, as well as more advanced tasks, including reliability analysis and fatigue assessment. However, this may only be achieved by means of repetitive analyses of the forward model, which implies considerable computational toll, when the model used is a detailed FE representation. In tackling this issue, reduced order models can be adopted, which retain the parameterisation and link to the parameters regulating the physical properties, albeit greatly reducing the computational burden. In this work a detailed FE model of a wind turbine tower is considered, reduced forms of this model are found using both the Craig Bampton and Dual Craig Bampton methods. These reduced order models are then used and compared in a Transitional Markov Chain Monte Carlo procedure to localise and quantify damage which is introduced to the system.