Dr Mahmoud Mostafavi, Faculty of Engineering, Bristol University, UK

Modelling and measurement of visco-plastic deformation of cubic systems at micro-level
When Mar 09, 2020
from 02:00 PM to 03:00 PM
Where LR1
Contact Name
Contact Phone 01865 273651
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A combination of experimental and computation materials engineering can stimulate enhanced understanding of material micromechanical behaviour when subjected to complex loading, particularly evident when extended to consider the influence of different loading scenarios on the structural life of components.  Crystal plasticity finite element (CPFE) modelling is an effective tool from which detailed information on the meso-scale behaviour of crystalline metallic systems can be extracted and used, not only to enhance the understanding of material behaviour under different loading conditions, but also to improve the structural integrity assessment of engineering components. To be of full benefit however it must demonstrate to not only predict the average global response of the material, but also the local behaviour, which controls damage. In this study, a crystal plasticity constitutive model is developed to improve the simulation capability of time independent and time dependent plasticity.  Comparison has been made between the macro-mechanical behaviour predicted by the model and experiments carried out at engineering length scale.  Critically, the macro-mechanical behaviour predicted by the model has been examined against the behaviour of the materials at meso-scale crystalline level measured synchrotron X-ray and neutron diffraction diffraction experiments.  The robustness of the model is demonstrated on both the macro- and meso-scale through the successful prediction of macro-scale behaviour and lattice strain evolution under a variety of loading conditions. The model not only successfully recognised the influence of prior deformation on subsequent loading, but also complemented neutron diffraction data to enrich the understanding of the influence of an important loading condition on the deformation of grains within the material.