Neural Autoencoder-Based Structure-Preserving Model Order Reduction and Control Design for High-Dimensional Physical Systems

This letter concerns control-oriented and structure-preserving learning of low-dimensional approximations of high-dimensional physical systems, with a focus on mechanical systems. We investigate the integration of neural autoencoders in model order reduction, while at the same time preserving Hamiltonian or Lagrangian structures. We focus on...

Efficient Methods for Spectral Geometry Processing

Research in geometry processing concerns the design of algorithms and mathematical models for the analysis and manipulation of geometric data. Examples of its applications are shape projection (e.g. smoothing and filtering), shape correspondence (e.g. functional maps), shape descriptors (e.g. heat and wave kernel signatures), segmentation, and...

Parameter estimation for a global tide and surge model with a memory-efficient order reduction approach

Accurate parameter estimation for the Global Tide and Surge Model (GTSM) benefits from observations with long time-series. However, increasing the number of measurements leads to a large computation demand and increased memory requirements, especially for the ensemble-based methods that assimilate the measurements at one batch. In this study,...

Simultaneous Optimisation of Composite Wing Structures and Control Systems for Active and Passive Load Alleviation

Future composite aircraft wing designs will exploit anisotropic material properties by aeroelastic tailoring and include active control methods for manoeuvre and gust load alleviation. The research focuses on the simultaneous optimisation of aeroelastically tailored wing structures with active manoeuvre and gust load alleviation as well as the...

Methods for Efficient Analysis of Vibro-Acoustic Problems

In this thesis, we present numerical techniques for analyzing vibro-acoustic problems that emerge from the coupling of elastic structures with fluid domains. The main analysis tool used for numerical modelling is the Finite Element Technique (FEM). By using FEM, the goal of our research was to either improve the already available techniques or...

A momentum subspace method for the model-order reduction in nonlinear structural dynamics: Theory and experiments

The article proposes a method developed for model order reduction in a Finite Element (FE) framework that is capable of computing higher order stiffness tensors. In the method, a truncated third order asymptotic expansion is used for transformation of an FE model to a reduced system. The basis matrix in the formulation of the reduced-order...

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...

Model order reduction and substructuring methods for nonlinear structural dynamics

Dynamic analysis of large-size finite element models has been commonly applied by mechanical engineers to simulate the dynamic behavior of complex structures. The ever-increasing demand for both detailed and accurate simulation of complex structures forces mechanical engineers to pursue a balance between two conflicting goals during the...

Model Order Reduction for Managed Pressure Drilling Systems based on a model with local nonlinearities

Automated Managed Pressure Drilling (MPD) is a method for fast and accurate pressure control in drilling operations. The achievable performance of automated MPD is limited, firstly, by the control system and, secondly, by the hydraulics model based on which this control system is designed. Hence, an accurate hydraulics model is needed that,...

POD-DEIM model order reduction for strain softening viscoplasticity

We demonstrate a Model Order Reduction technique for a system of nonlinear equations arising from the Finite Element Method (FEM) discretization of the three-dimensional quasistatic equilibrium equation equipped with a Perzyna viscoplasticity constitutive model. The procedure employs the Proper Orthogonal Decomposition-Galerkin (POD-G) in...

A geometric approach to nonlinear dissipative balanced reduction: Continuous and sampled-time

In almost every field of applied science and engineering, dynamical models are widely used as a professional tool to describe in a compact format the scientific knowledge we have about the phenomena we are analyzing. Such models are widely used for the estimation, optimization, detection of failures and even for real-time control. The relevance...

Towards a data assimilation system for morphodynamic modeling

Currently, available models are not able to accurately predict the temporal evolution of coastal morphodynamic processes. The main reason for this, is that essential components governing this evolution are neither fully identified nor understood. Additionally, there is high uncertainty in some of the parameterizations and their input parameters....

Efficient Preconditioners for PDE-Constrained Optimization Problems with a Multi-level Sequentially Semi-Separable Matrix Structure

In this paper, we consider preconditioning for PDE-constrained optimization problems. The underlying problems yield a linear saddle-point system. We study a class of preconditioners based on multilevel sequentially semiseparable (MSSS) matrix computations. The novel global preconditioner is to make use of the global structure of the saddle-point...

A Krylov stability-corrected coordinate-stretching metho to simulate wave propagation in unbounded domains

The Krylov subspace projection approach is a well-established tool for the reducedorder modeling of dynamical systems in the time domain. In this paper, we address the main issues obstructing the application of this powerful approach to the time-domain solution of exterior wave problems. We use frequency-independent perfectly matched layers to...