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Multiscale Deformation Modelling of Small Scale Mechanical Tests / TRISTAN KAY
Swansea University Author: TRISTAN KAY
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Copyright: The Author, Tristan Hearsey McKay, 2024 Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0)
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DOI (Published version): 10.23889/SUThesis.71076
Abstract
Novel techniques that accelerate the development of new steel alloys by combining miniaturised tests with modelling techniques is key for TATA steel to remain competitive. The research undertaken here modelled the deformation of small-scale mechanical tests of dual-phase steels as part of a Rapid Al...
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Swansea
2025
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | EngD |
| Supervisor: | Harrison, W.; Farrugia, D.; and Peric, D. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa71076 |
| Abstract: |
Novel techniques that accelerate the development of new steel alloys by combining miniaturised tests with modelling techniques is key for TATA steel to remain competitive. The research undertaken here modelled the deformation of small-scale mechanical tests of dual-phase steels as part of a Rapid Alloying Process. This was achieved via a multiscale approach using finite element models developed in ABAQUS to simulate deformation of shear punch tests at the continuum level and microstructural deformation modelling via representative volume elements using synthetically generated microstructures. An axisymmetric modelling approach was first used to validate geometrical parameters of the shear punch test. This showed that the radius of the punch head and corner tip radiuses are key aspects that must be controlled for when setting up experimental test rigs to ensure that shear dominant deformation takes place and minimize other deformation mechanisms like bending or stretching of test pieces. A 3D half-symmetry model was developed to review advanced damage mechanisms that develop during shear punch tests. From this it was concluded that due to the multiphase nature of dual phase steels, continuum modelling alone is not enough to characterise the deformation of dual phase steels. Whilst strength characteristics of dual phase correlated well with experimental tests the ductility and elongation values did not correlate with real world experimentation.Microstructural deformation was modelled using representative volume elements to characterise the deformation of a pure ferrite-martensite dual phase steel using both 2D and 3D models. Synthetic models using a composite approach with variable martensite content were successfully used to review dual phase steel deformation, generating better results than using a real microstructure. This work produced a plug-in script which was used to automatically generate 2D microstructural models of dual phase steels whose parameters could easily be varied. Whilst the 2D microscale modelling approach was not exhaustive in accounting for all characteristics of dual phase alloy, it did show that composite modelling of these kinds of steels can be used to generate reliable predictions of mechanical properties and deformation evolution when used for the development prototype steel alloys as part of a Rapid Alloy Prototyping process. |
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| Keywords: |
Shear Punch Test, Dual Phase Steel, Representative Volume Elements, microscale modelling, geometry parameters, axisymmetric modelling, Rapid Alloy Prototyping, Shear Punch Modelling |
| College: |
Faculty of Science and Engineering |
| Funders: |
EPSRC doctoral training grant, Tata Steel |