# Philip CardiffUniversity College Dublin | UCD · School of Mechanical and Materials Engineering

Philip Cardiff

B. E. (Mech) Ph.D.

## About

201

Publications

187,705

Reads

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1,617

Citations

Introduction

I am interested in the finite volume, finite element and related numerical methods, with a particular interest in the finite volume method for solid mechanics and fluid-solid interaction.
In parallel, I am also interested in novel methods for combining machine learning with traditional computational methods, as well as other nascent technologies.

Additional affiliations

August 2015 - present

January 2015 - August 2015

March 2012 - February 2015

**University College Dublin**

Position

- PostDoc Position

Education

November 2008 - November 2012

## Publications

Publications (201)

This study employs a high-fidelity numerical approach to simulate fluid-structure interaction phenomena for the dynamic response of flexible hyperelastic morphing wing structures under low aerodynamic loads. The computations are performed using the open-source solids4Foam toolbox, employing a partitioned two-way fluid-structure interaction approach...

In this presentation, a new approach based on Simo-Reissner Beam theory was introduced as an OpenFOAM Restraint Library. This beam theory, in essence, can solve problems with large displacements, which makes it a great tool in simulating mooring lines as beams, which, due to the nature of extreme waves, makes the beam have a non-linear and large di...

This presentation describes a method to accelerate segregated finite-volume solid mechanics solvers for both linear and non-linear geometry. The main methodology is to use a machine learning model to predict the converged displacement field of a fine mesh test case. The machine learning model is a supervised artificial neural network trained on dat...

This presentation introduces the One-Step SelfSim algorithm for formulating material models using experimentally measured strain fields. This inverse method, based on the SelfSim algorithm (originally known as Autoprogressive), trains a machine learning model with a reference behaviour, such as linear elasticity, that is expected to provide a reaso...

This paper presents an adaption of the finite-element based beam-to-beam contact interactions into a finite volume numerical framework. A previous work of the same authors, where a cell-centred based finite volume implementation of geometrically exact nonlinear Simo–Reissner beams was developed, is used as an underlying mathematical model. An impli...

For videos to be shown, see the original presentation (link below), or contact me.
https://ucd-my.sharepoint.com/:p:/g/personal/ali_shayegh_ucdconnect_ie/EZFPrt441L5PvI-FepttjYEBnoDJ8gC_14xq_PkzdZixaQ?e=awl6GH

Estimating the properties of dissimilar metal welded joints made using modern high-energy beam techniques presents significant challenges due to the complex nature of the process. These complexities arise from the different thermal and mechanical properties of the materials involved. The properties of a welded joint are primarily determined by the...

In this update to the laserbeamFoam toolbox, a multi-component version of the solver is included with pair- wise Fickian Diffusion between selected component pairs. This new solver, multiComponentlaserbeamFoam, captures the multi-component nature of mixing between alloys, and as-such could be used to simulate dissimilar laser joining processes, and...

A computational framework is developed to understand the transient behavior of isothermal and non-isothermal transformation between liquid and solid phases in a binary alloy using a phase-field method. The non-isothermal condition was achieved by applying a thermal gradient along the computational domain. The bulk solid and liquid phases were treat...

Aerodynamic performance is of critical importance to the design of long-span bridges. Computational fluid dynamics (CFD) modelling offers bridge designers an opportunity to investigate aerodynamic performance for long-span bridges during the design phase as well as during operation of the bridge. It offers distinct advantages when compared with the...

Investigating floating structures affected by ocean waves using computational fluid dynamics (CFD) models has grown in popularity, particularly for installing floating offshore wind turbines.
There has been tremendous progress in this area, including recent studies such as MoorDyn and Moody, which proposed high-fidelity models for mooring line dyna...

In this presentation, we demonstrate how to implement the Autoprogressive (or SelfSim) algorithm in a finite volume context. The mechanics solver we use is OpenFOAM, the machine-learning methods are Python-based, and the OpenFOAM/Python interoperability is achieved via the pythonPal4foam OpenFOAM library.

The uniformity and concentricity of the coating layer via wiping jet technique is one the main concerns in the hot-dip galvanising of steel wires. This study aims to capture the pressure and shear stress on the coating layer produced by a specific design of a jet-wiping nozzle.

This presentation describes a method to accelerate segregated linear elastic solid mechanics solvers. The main methodology is to use a machine learning model to predict the converged displacement field of a fine mesh test case. The machine learning model is a supervised artificial neural network trained on data from an identical coarse mesh case....

In the past half-century, there has been tremendous progress in biomedical imaging; nonetheless, a multitude of cardiac physical phenomena are not easily observed in vivo. In silico studies are uniquely placed to provide valuable diagnostic insights and aid in the development of new medical devices and therapies. Cardiac functioning is governed by...

A short training course on the use of solids4foam-v2.0

The properties of intracranial aneurysms (IAs) walls are known to be driven by the underlying hemodynamics adjacent to the IA sac. Different pathways exist explaining the connections between hemodynamics and local tissue properties. The emergence of such theories is essential if one wishes to compute the mechanical response of a patient-specific IA...

This article presents a new implicit coupling procedure for mechanical contact simulations using an implicit cell-centred finite volume method. Both contact boundaries are treated as Neumann conditions, where the prescribed contact force is calculated using a penalty law, which is linearised and updated within the iterative solution procedure. Comp...

The safety and serviceability of long-span bridges can be significantly impacted by wind effects and therefore it is crucial to accurately estimate them during bridge design. This study develops full-scale 3-Dimensional CFD (computational fluid dynamics) simulation models to replicate wind conditions at the Rose Fitzgerald Kennedy Bridge in Ireland...

The application of high energy density photonic sources to the surface of metallic substrates causes localised topological evolution as the interface deforms due to hydrodynamic forces through fusion and vapourisation state transitions. Understanding how this laser energy is deposited, which may involve multiple reflection events, coupled with a th...

This article proposes two approaches for combining finite volume and machine learning techniques to solve linear elastostatic problems. The first approach adopts a classical supervised machine learning model and generates the training dataset by finite volume-based solvers. The second approach applies a physics-informed model to enforce the governi...

Towards the development of modelling approaches for fatigue life assessment of TAVR systems under in-vivo and in-vitro (pulse duplicator) loading conditions, the impact of bioprosthetic valve leaflet material properties should be considered. The leaflets considered in this study are porcine pericardium. Variations in leaflet stiffness can be as lar...

The properties of intracranial aneurysms (IAs) walls are known to be driven by the underlying hemodynamics adjacent to the IA sac. Different pathways exist explaining the connections between hemodynamics and local tissue properties. The emergence of such theories is essential if one wishes to compute the mechanical response of a patient-specific IA...

As the overlap between traditional computational mechanics and machine learning grows, there is an increasing demand for straightforward approaches to interface Python-based procedures with C++-based OpenFOAM. This article introduces one such general methodology, allowing the execution of Python code directly within an OpenFOAM solver without requi...

This article proposes two approaches for combining finite volume and machine learning techniques to solve linear elastostatic problems. The first approach adopts a classical supervised machine learning model and generates the training dataset by classical finite volume-based solvers. The second approach applies a physics-informed model to enforce t...

Numerical simulations have been extensively used in the past two decades for the study of intracranial aneurysms (IAs), a dangerous disease that occurs in the arteries that reach the brain. They may affect up to 10 % of the world's population, with up to 50 % mortality rate, in case of rupture. Physically, the blood flow inside IAs should be modele...

Numerical simulations have been extensively used in the past two decades for the study of intracranial aneurysms (IAs), a dangerous disease that occurs in the arteries that reach the brain and affect overall 3.2 % of a population without comorbidity with up to 60 % mortality rate, in case of rupture. The majority of those studies, though, assumed a...

The focus of this research is to develop a simulation methodology for the design of next-generation Transcatheter Aortic Valve Replacement (TAVR) devices. Initial results presented here focus on the structural analysis of a commercially available TAVR device, where in-vitro pulsatile loading is captured through time-varying pressure conditions appl...

The modelling of wave-structure interaction (WSI) has significant applications in understanding natural processes as well as securing the safety and efficiency of marine engineering. Based on the technique of Computational Fluid Dynamics (CFD) and the open-source simulation framework - OpenFOAM, this paper provides a state-of-the-art review of WSI...

This work presents an educational Python framework for a 2D linear elastic implicit segregated solid solver for a structured mesh based on the methods used in solids4foam. This framework is composed of a series of Jupyter notebooks that provide an in-depth explanation of each step required to build the solid solver.

A general approach to deriving the symmetry plane boundary conditions for cell-centered finite-volume continuum mechanics is presented. It is equally applicable to scalar, vector, and tensor solution variables. The total contribution of the symmetry plane cell faces to the next-to-symmetry-plane cells is decomposed into implicit and explicit parts,...

The modelling of wave-structure interaction (WSI) has significant applications in understanding natural processes as well as securing the safety and efficiency of marine engineering. Based on the technique of Computational Fluid Dynamics (CFD) and the open-source simulation framework - OpenFOAM, this paper provides a state-of-the-art review of WSI...

This presentation details how to use a machine learning model as an initialiser for the iterative solver in OpenFOAM. The results for three test cases in linear elasticity demonstrate the speedup and effectiveness of such an approach.

This presentation outlines the development and verification of an implicit vertex-centred finite volume method in OpenFOAM. Nonlinearities are resolved using a Newton-Raphson loop with line search and the linear system is solved in parallel using PETSc.

Introductory training for solids4foam demonstrating the wobblyNewton and flexibleDamBreak cases.

Overview of the solids4foam toolbox with examples and comments on future directions for solids4foam-v2.0.

Numerical simulations have been extensively used in the past two decades for the study of intracranial aneurysms (IAs), a dangerous disease that occurs in the arteries that reach the brain. They may affect up to 10 % of the world's population, with up to 50 % mortality rate, in case of rupture. Physically, the blood flow inside IAs should be modele...

High energy density advanced manufacturing processes, such as power beam welding and additive manufacturing, are notoriously difficult to simulate. Such processes initiate fusion, and vapourisation, state transitions in their respective (normally metallic) substrates generating complex metallic flows over incredibly short time scales. To mathematic...

This paper presents a novel total Lagrangian cell‐centred finite volume formulation of geometrically exact beams with arbitrary initial curvatures undergoing large displacements and finite rotations. The choice of rotation parametrisation, the mathematical formulation of the beam kinematics, conjugate strain measures and the linearisation of the st...

As the overlap between traditional computational mechanics and machine learning grows, there is an increasing demand for straight-forward approaches to interface Python-based procedures with C++-based OpenFOAM. This article introduces one such general methodology, allowing the execution of Python code directly within an OpenFOAM solver without the...

The powder bed fusion (PBF) process, an additive manufacturing technique, uses a laser/electron beam to selectively melt and fuse metal powder in a layer-wise manner to fabricate products. The complexities that arise during fabrication can be modeled using numerical methods, aiding experiments to provide a better understanding of the process. Here...

PhD Interdoctoral Course at Politecnico di Milano
COMPUTATIONAL FLUID DYNAMICS
WITH OPEN-SOURCE SOFTWARE
2-4 February 2022 / 15-17 February 2022

PhD Interdoctoral Course at Politecnico di Milano
COMPUTATIONAL FLUID DYNAMICS
WITH OPEN-SOURCE SOFTWARE
2-4 February 2022 / 15-17 February 2022

PhD Interdoctoral Course at Politecnico di Milano
COMPUTATIONAL FLUID DYNAMICS
WITH OPEN-SOURCE SOFTWARE
2-4 February 2022 / 15-17 February 2022

Despite its wide acceptance in various industries, CFD is considered a secondary option to wind tunnel tests in bridge engineering due to a lack of confidence. To increase confidence and to advance the quality of simulations in bridge aerodynamic studies, this study performed three-dimensional RANS simulations and DESs to assess the bridge deck aer...

Toe caps are one of the most important components in safety footwear, but have a significant contribution to the weight of the shoe. Efforts have been made to replace steel toe caps by polymeric ones, since they are lighter, insulated and insensitive to magnetic fields. Nevertheless, polymeric solutions require larger volumes, which has a negative...

This article examines the effect of braid angle on the mechanical performance of carbon-epoxy braided tubes in tension and compression. Vacuum-assisted resin transfer moulding is used to produce a variety of tubes with several combinations of 15◦ and 20◦ braid angles. As uniaxial tensile testing of cylindrical tubes is not trivial, two tensile test...

Although intracranial aneurysms (IAs) have been extensively investigated in the last three decades by using numerical techniques, the bulk of these works have been focused on using Computational Fluid Dynamics (CFD) to simulate the blood flow, since substantial evidence shows that hemodynamics plays a crucial role in this pathology. However, most w...

Finite element and related methods have seen significant success in the analysis of complex metal forming problems, however, when large elasto-plastic strains are present the ability of the constitutive model to accurately describe the material behaviour can be a limiting factor.
There is no universal expression that describes the observed stress-s...

This presentation describes two different machine learning models for the solution of problems in linear elasticity: Physics-Informed Neural Network (PINN) and Finite Volume (FV) informed model. While both approaches define loss in terms of the residual of the governing equations, they are different in application. The PINN aims to solve a single c...

The implementation of two damage models and the phase field fracture model in OpenFOAM

This paper presents a novel total Lagrangian cell-centred finite volume formulation of geometrically exact beams with arbitrary initial curvature undergoing large displacements and finite rotations. The choice of rotation parametrisation, the mathematical formulation of the beam kinematics, conjugate strain measures and the linearisation of the str...

This paper presents a new contact boundary condition for finite volume simulations of frictional contact problems involving geometrical and material non-linearities. Deformation of bodies in contact is described by the updated Lagrangian form of the momentum equation which is discretised in space using the cell-centred finite volume method. The pro...

This work presents a novel supervised regression machine learning model which has been trained to predict the converged (final iteration) interface deflection values from the initial iteration values. This model has been implemented into solids4foam, an open-source toolbox for solid mechanics and fluid-solid interactions in OpenFOAM built by Cardif...

Describes the implementation of damage mechanics and fracture models in OpenFOAM

A FV-Informed Machine Learning technique is presented. This ML model can learn numerical solution procedures in linear elastic solvers without requiring prior solutions (ground-truth data). As a result, it can be used as either surrogate or initialiser for the conventional solvers. OpenFOAM libraries are used to generate organized data, required fo...

In this work, extension of finite volume solver for geometrically exact Simo-Reissner beam to model polygonal cross sectional wire geometries is presented