Generic Property Modelling
The aim is to develop micromechanical models that allows for the evaluation of mechanical properties of single and multi-phase steels.
The mechanical behavior of a polycrystalline metal on the macro scale depends on its complex structure on the micro scale ranging from nanometers to microns. Hence, upon loading, the state of deformation on the micro scale in such a material system will be highly heterogeneous, even if a homogeneous load is applied on the macro scale. The presence of heterogeneous deformation introduces size scale effects in the material. For instance, the well-known Hall-Petch relation between grain size and strength is an example of this. There, the underlying mechanism and source of micro scale heterogeneity is due to grain boundaries, which raises the resistance towards plastic flow deformation resulting in increased strength of the material. Another example is precipitation and dispersion hardening, where the strengthening effect depends strongly on the particle size and inter-particle spacing. Standard elastic-plastic continuum theories are not able to capture these effects, as they lack a sense of scale.
The tools to be developed will in turn facilitate the development of constitutive models with internal variables that accounts for inelastic deformation. An accurate description of the inelastic response of a material will also facilitate the development of a suitable micromechanics model that can be used to find out the fracture properties of the material. This is important, since the latter ultimately will limit the applicability of the material.