“Weld modelling” is a powerful multi-disciplinary tool for understanding the structural performance of welded structures. Its state of the art as an industrial tool is in continuum-mechanics based prediction of residual stresses and distortions in materials that do not undergo solid state phase transformations, and subsequent assessment of structural performance using those continuum stresses.
In practice, of course, the microstructural changes imposed by welding have a profound influence on subsequent structural performance, via the materials’ resistance to creep, thermal ageing, oxidation, stress corrosion and other degradation mechanisms. When solid state phase transformation takes place during welding, as it does for many common steel alloys, then it is necessary to predict microstructural changes merely to establish the as-welded residual stresses and distortions.
Our aim is to extend weld modelling into a multi-disciplinary tool that can predict both continuum behaviour and microstructural parameters, and hence both directly predict long term structural performance and be used for “virtual prototyping “ of novel weld processes and procedures.
Our research looks at:
- Developing and validating techniques to reliably predict residual stresses and distortions in complex structural weldments manufactured using both conventional arc-welding processes and novel techniques such as laser welding.
- Accurate prediction of the extent and significance of solid state phase transformation in multi-pass weldments with complex thermo-mechanical histories and repeated phase transformations.
- Direct prediction of microstructural development in welds, and its significance for long term structural performance.
- Development and understanding of narrow gap welding processes for next generation nuclear power plants and Generation IV reactor designs
- Virtual prototyping of novel weld processes and procedures
- Reliable in-service structural performance of existing nuclear reactor designs
- High integrity welded plant in other industries such as Oil & Gas.