A linearisedhp-finite element framework for acousto-magneto-mechanical coupling in axisymmetric MRI scanners: ACOUSTO-MAGNETO-MECHANICAL COUPLING IN MRI SCANNERS

Bagwell, Scott; Ledger, Paul D; Gil, Antonio J; Mallett, Mike; Kruip, Marcel

Abstract

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 hp–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.

Citation

Bagwell, S., Ledger, P. D., Gil, A. J., Mallett, M., & Kruip, M. (2017). A linearisedhp-finite element framework for acousto-magneto-mechanical coupling in axisymmetric MRI scanners: ACOUSTO-MAGNETO-MECHANICAL COUPLING IN MRI SCANNERS. International Journal for Numerical Methods in Engineering, 112(10), 1323-1352. https://doi.org/10.1002/nme.5559

• Journal Article Type: Article
• Acceptance Date: Apr 1, 2017
• Online Publication Date: Jul 13, 2017
• Publication Date: Dec 7, 2017
• Deposit Date: Jun 12, 2023
• Journal: International Journal for Numerical Methods in Engineering
• Print ISSN: 0029-5981
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 112
• Issue: 10
• Pages: 1323-1352
• DOI: https://doi.org/10.1002/nme.5559
• Keywords: Applied Mathematics; General Engineering; Numerical Analysis