The Duncan Calder PhD Scholaship in Microstructural characterisation and static and dynamic properties of resistance spot-welded DP1000 steel

The proposed Ph.D. project aims to characterise and simulate the behaviour of resistance spot-welded DP1000 steel. It will also contribute to the understanding of the microstructural changes that take place during resistance spot-welding (RSW) and to the subsequent effect on the behaviour of the spot-welded joints. Simulation will be conducted using existing Finite Element Analysis (FEA) software and compared (and corroborated) with the experimental results. The proposed study will involve:

1. Literature review.
2. Understanding the background to the project and the use of the Helipipe interlocking ribbed pipe structure.
3. Simulation and corroboration of FEA modelling of the effect of the RSW parameters on the heat-affected zone (HAZ) microstructure, lap-shear and pull-out strength of joints and low-velocity impact strength.
4. Understanding of the effect of the RSW parameters on the size and microstructure of the HAZ and on the corrosion and fatigue behaviour of the joints. Microscopy will also be conducted in order to examine the mechanism of fatigue failure.
5. Design, build and test the electrode-positioning head for integration into the RSW equipment that will be used in straight helical pipe manufacture and joint connection. Trials will then be conducted to produce viable RSW joints.