Print
Bulk Magnets
Author: , Posted: 1385381820.

Bulk Magnets

Dr LEONG  Zhaoyuan

Project

Magnetostrictive sensors for composite structural health monitoring

Abstract

Composites, although possessing good properties are subject to complicated modes of failure; often these damages are barely visible as they may be located between composite layers. Structural Health Monitoring (SHM) of aircraft composite is required to determine the barely visible impact damage (BVID) that occurs during flight; if caught early before the damage becomes irreparable, it can be repaired in-situ, so saving money and time. BVID causes a strain within the composite, which can be measured, using surface mounting techniques such as fibre optics and piezoelectric sensors

This work focuses on the development of a magnetostrictive sensor capable of detecting barely-visible-damage (BVD), essential to the usage of composites in high-performance environments such as in the aerospace industry. The sensor design consists of a magnetostrictive actuator couple with a magnetic sensor. Several strategies are being investigated at the moment in order to determine the most cost-effective method for BVD detection using magnetostrictive materials.

Funded by the European JTI-CleanSky2 program (SHERLOC)

Mr Robin Pillar

Project

Nd-Fe-B Permanent Magnets

Abstract

This project investigates how microstructural features and composition affect the magnet properties of Nd-Fe-B permanent magnets. Nd-Fe-B magnets have the highest energy product of any magnetic material (512 kJ m3) and are widely used in wind turbine generators.

The composition of the Nd-rich phase between the Nd2Fe14B grains is thought to play a key role in the magnetic properties of the material, but there is still a lot not known about it.

Using a combination of SEM techniques and finite element modelling this project aims to study how changes to the microstructure and composition of the Nd-rich phase effects the overall magnetic properties of the material 

Supervisors

Dr Julian Dean and Prof Dan Allwood

Funded by the Engineering Physical Sciences Research Council and Siemens Gamesa

Mr Patrick Pan

Project

Monitoring of Intermediate Level Waste (ILW) Packages using Magnetic Sensors

Abstract

The project focuses on an alternative method to monitor Intermediate Level Waste (ILW) packages (which are securely stored in nuclear-licensed sites) until they can be safely disposed of in a Geological Disposal Facility (GDF). The timescales associated with developing a GDF storage could be up to many decades. Over these timescales, a fraction of ILW packages will undergo expansion due to the corrosion of reactive metal within the waste. Hence, it is crucial to monitor the rate of expansion to determine the stability of the waste packages during the period of interim storage, to ensure they meet the acceptance criteria of the GDF.

This alternative monitoring method is to use a stress sensitive magnetic sensor which utilises the Giant Magnetoimpedance (GMI) effect.

Supervisors

Dr Tom Hayward and Dr Claire Corkhill

Funded by the Nuclear Decommissioning Authority (NDA) and National Nuclear Laboratory (NNL)

http://magnetics.group.shef.ac.uk/page.php?id=82