A machine-learning enabled framework for quantifying uncertainties in parameters of computational models

T Roper, H Hakula, T Butler - Computers & Mathematics with Applications, 2025 - Elsevier
This work presents novel extensions for combining two frameworks for quantifying both
aleatoric (ie, irreducible) and epistemic (ie, reducible) sources of uncertainties in the …

[HTML][HTML] On effects of concentrated loads on perforated sensitive shells of revolution

S Giani, H Hakula - Journal of Computational and Applied Mathematics, 2023 - Elsevier
Sensitive shells are a class of constructions with specific and perhaps unintuitive responses
to different loading scenarios. There are new emerging applications for capsules with open …

From Displacements to Distributions: A Machine-Learning Enabled Framework for Quantifying Uncertainties in Parameters of Computational Models

T Roper, H Hakula, T Butler - arxiv preprint arxiv:2403.03233, 2024 - arxiv.org
This work presents novel extensions for combining two frameworks for quantifying both
aleatoric (ie, irreducible) and epistemic (ie, reducible) sources of uncertainties in the …

Benchmark computations of stresses in a spherical dome with shell finite elements

AH Niemi - SIAM Journal on Scientific Computing, 2016 - SIAM
We present a computational framework for analyzing thin shell structures using the finite
element method. The framework is based on a mesh-dependent shell model which we …

A bilinear shell element based on a refined shallow shell model

AH Niemi - International journal for numerical methods in …, 2010 - Wiley Online Library
A four‐node shell finite element of arbitrary quadrilateral shape is developed and applied to
the solution of static and vibration problems. The element incorporates five generalized …

Effects of Internal Boundary Layers and Sensitivity on Frequency Response of Shells of Revolution

H Hakula - Vibration, 2023 - mdpi.com
New applications introduced capsule designs with features that have not been fully
analysed in the literature. In this study, thin shells of revolution are used to model drug …

Approximation of shell layers using bilinear elements on anisotropically refined rectangular meshes

AH Niemi - Computer methods in applied mechanics and …, 2008 - Elsevier
In this paper, we study numerical locking effects in the finite element approximation of shell
layers. The focus is on four-node degenerated elements that are perhaps the most widely …

Implementing model reduction to the JuliaFEM platform

M Rapo, J Aho, H Koivurova, T Frondelius - 2018 - oulurepo.oulu.fi
JuliaFEM is an open source finite element method solver written in the Julia language. This
paper presents an implementation of two common model reduction methods: the Guyan …

[PDF][PDF] Isogeometric shell formulation based on a classical shell model

AH Niemi, N Collier, L Dalcin… - proceedings of the …, 2012 - webapp.tudelft.nl
Abstract We study a Reissner-Mindlin shell formulation for NURBS-based isogeometric
analysis. The formulation is based on a shell model which utilizes curvilinear coordinates …

[BOOK][B] Best bilinear shell element: flat, twisted or curved?

AH Niemi - 2009 - aaltodoc.aalto.fi
This thesis concerns the accuracy of finite element models for shell structures. The focus is
on low-order approximations of layer and vibration modes in shell deformations with …