On generative models as the basis for digital twins

TL;DR

This paper explores the use of generative models, including physics-based stochastic finite element models and data-driven cGANs, as digital twins for structures, demonstrating their effectiveness and potential hybridization.

Contribution

It introduces a framework combining physics-based and data-driven generative models for digital twins, highlighting their advantages and a hybrid approach.

Findings

SFE models can outperform other models when physics are accurately captured.

cGANs outperform physics-based models in nonlinear, uncertain scenarios.

Hybrid models effectively combine physics-based and data-driven methods.

Abstract

A framework is proposed for generative models as a basis for digital twins or mirrors of structures. The proposal is based on the premise that deterministic models cannot account for the uncertainty present in most structural modelling applications. Two different types of generative models are considered here. The first is a physics-based model based on the stochastic finite element (SFE) method, which is widely used when modelling structures that have material and loading uncertainties imposed. Such models can be calibrated according to data from the structure and would be expected to outperform any other model if the modelling accurately captures the true underlying physics of the structure. The potential use of SFE models as digital mirrors is illustrated via application to a linear structure with stochastic material properties. For situations where the physical formulation of such models does not suffice, a data-driven framework is proposed, using machine learning and conditional generative adversarial networks (cGANs). The latter algorithm is used to learn the distribution of the quantity of interest in a structure with material nonlinearities and uncertainties. For the examples considered in this work, the data-driven cGANs model outperform the physics-based approach. Finally, an example is shown where the two methods are coupled such that a hybrid model approach is demonstrated.