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A linearised hp –finite element framework for acousto‐magneto‐mechanical coupling in axisymmetric MRI scanners
Author(s) -
Bagwell Scott,
Ledger Paul D,
Gil Antonio J,
Mallett Mike,
Kruip Marcel
Publication year - 2017
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.5559
Subject(s) - finite element method , discretization , benchmark (surveying) , rotational symmetry , coupling (piping) , excitation , mechanical system , magneto , transient (computer programming) , computer science , current (fluid) , nonlinear system , harmonic , physics , mathematics , mathematical analysis , mechanical engineering , engineering , mechanics , acoustics , structural engineering , geodesy , rotor (electric) , geography , operating system , quantum mechanics , thermodynamics
Summary We propose a new computational framework for the treatment of acousto‐magneto‐mechanical coupling that arises in low‐frequency electro‐magneto‐mechanical systems such as magnetic resonance imaging scanners. Our transient Newton–Raphson strategy involves the solution of a monolithic system obtained from the linearisation of the coupled system of equations. Moreover, this framework, in the case of excitation from static and harmonic current sources, allows us to propose a simple linearised system and rigorously motivate a single‐step strategy for understanding the response of systems under different frequencies of excitation. Motivated by the need to solve industrial problems rapidly, we restrict ourselves to solving problems consisting of axisymmetric geometries and current sources. Our treatment also discusses in detail the computational requirements for the solution of these coupled problems on unbounded domains and the accurate discretisation of the fields using h p –finite elements. We include a set of academic and industrially relevant examples to benchmark and illustrate our approach. Copyright © 2017 The Authors. International Journal for Numerical Methods in Engineering Published by John Wiley & Sons, Ltd.