Structure-Preserving Hyper-Reduction Methods for the Incompressible Navier-Stokes Equations

In this master thesis several novel DEIM formulations are proposed that enable the construction of non-linearly stable hyper-reduced order models (hROMs) of the incompressible Navier-Stokes equations. The hROMs have the same mass, momentum and energy conservation properties as the previously proposed ROM, but they do not suffer of prohibitively...

An adaptive domain-based POD/ECM hyper-reduced modeling framework without offline training

This work presents a reduced-order modeling framework that precludes the need for offline training and adaptively adjusts its lower-order solution space as the analysis progresses. The analysis starts with a fully-solved step and elements are clustered based on their strain response. Elements with the highest strains are solved with a local...

Micromechanics-based surrogate models for the response of composites: A critical comparison between a classical mesoscale constitutive model, hyper-reduction and neural networks

Although being a popular approach for the modeling of laminated composites, mesoscale constitutive models often struggle to represent material response for arbitrary load cases. A better alternative in terms of accuracy is to use the FE² technique to upscale microscopic material behavior without loss of generality, but the...

Accelerating crack growth simulations through adaptive model order reduction

Accurate numerical modeling of fracture in solids is a challenging undertaking that often involves the use of computationally demanding modeling frameworks. Model order reduction techniques can be used to alleviate the computational effort associated with these models. However, the traditional offline-online reduction approach is unsuitable...

Investigation of Accuracy, Speed and Stability of Hyper-Reduction Techniques for Nonlinear FE

The field of Hyper-reduction for Nonlinear Finite Element Method attempts to address the large durations due to repeated evaluation and assembly of the internal force and Jacobian. Stability, accuracy and speed are three aspects of thesemethods that has been dealt with in this thesis. There are two methods that are popular within the...