PhD Studentship: Fatigue evaluations of additive manufactured materials in novel heat exchanger des

Location: Highfield Campus

Closing Date:  Friday 29 September 2017

Reference: ENGSCI-MATS-380

Heat exchangers are used widely throughout the automotive, marine and aerospace sectors and are traditionally designed as an assembly of fins and tubes. Modern additive manufacturing (AM) processes may enable complex internal cooling passages to be manufactured with relative ease, allowing the development of radically new designs of the next generation of heat exchangers by manipulating internal shapes and topologies. The general challenge of modelling materials behaviour and fatigue in a multi-material system subjected to vibration and combined thermal cycling has received most focus in turbomachinery such as high performance turbine blades. The added challenge provided by the envisaged complexity of designs containing AM multi-functional structures will require the development and use of appropriate materials models that capture the defect distributions within the AM parts as well as the appropriate materials constitutive models and fatigue criteria. Fatigue studies of AM systems are still in a relatively immature state due to the wide range of processing variables and resultant defect distributions and residual stress states that can be produced by structural changes. The PhD project will evaluate the fatigue performance of relevant materials under typical loading and thermal cycles produced by the service environment. This will include the development of appropriate constitutive materials models and fatigue lifing approaches to work with another PhD student on fatigue lifing of the structures in the design optimisation process. The effects of additive manufacturing processes on subsequent materials properties in the metamaterials structures will be a particular focus. This will require novel experimental characterisation of relevant joint microstructures under complex fatigue conditions; determination of appropriate constitutive materials models that reflect microstructure changes and the effect of AM microstructures. The effect of environment (e.g. salt deposits and moisture) on initiation and growth will also be evaluated to incorporate these effects in materials models used in subsequent lifing predictions. The goals will be to: (1) Establish an appropriate micromechanical basis for fatigue lifing within an integrated design and optimisation approach. (2) Deliver appropriate AM materials models for fatigue lifing. (3) Identify AM materials optimisation routes for fatigue resistance within the design approach

The successful candidate should have a good engineering or applied mathematics degree (or equivalent), ideally with experience in materials and mechanics. The successful candidate will also have the opportunity to work directly with Vestas in Denmark, gaining industrial experience during placements as part of their studies.

If you wish to discuss any details of the project informally, please contact Prof Philippa Reed, Materials Group, Email: pasr1@soton.ac.uk, Tel: +44 (0) 2380 593763 or Dr. Andrew Hamilton, Materials Group , Email: A.R.Hamilton@soton.ac.uk, Tel: +44 (0) 2380 598697