ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Materials by design: from the nanoscience to the macromechanics of modern steel alloys

Date: 17.09.2014
Time: 02:00 p.m.
Place: IC 02-718

Tarek Hatem, Department of Mechanical Engineering, British University in Egypt, Cairo, Egypt
Pratheek Shanthraj, Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany

Modern computer-based predictive methods, such as non-linear finite element methods can be used to shed light upon the physical mechanisms of deformation and failure of modern materials. From molecular dynamics to dislocation dynamics to dislocation-density based plasticity to generalized continuum methods, the details of nano-scale mechanisms to the complex mechanics of structural level failure can be modeled and simulated with the proposed coupled multiscale techniques. This work aims at presenting the potential of computational multiscale methods to predict and help tailor and design new steel alloys for improved performance.

The proposed methodology was used to investigate large strain inelastic deformation and heterogeneous failure modes in martensitic microstructures. The formulation is based on accounting for variant morphologies and orientations, secondary phases, and initial dislocations-densities that are uniquely inherent to martensitic microstructures. The interrelated effects of microstructural characteristics, such as parent austenite orientation, variants distribution and arrangement, retained austenite, inclusions, initial dislocation-density, and defects, such as microcracks, and microvoids, were investigated for different failure modes such as rupture, transgranular and intergranular fracture, and shear localization over a broad spectrum of loading conditions that range from quasi-static to high strain-rate conditions.

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