Materials Engineering - Metals and alloys - Multiscale deformation modelling of small scale mechanical tests

One of the aims of the Prosperity Partnership project is to accurately evaluate the mechanical properties of a large number of steels from small scale tests. An important aspect of mechanical behaviour during steel making is anisotropic yield and work-hardening caused by rolling processes. Both hot and cold rolling result in metallurgical texture which effects mechanical properties and subsequent forming processes. This is a particular issue for thin sheet steels used for metal forming such as deep drawing grades.
As the size of the deforming material becomes smaller, the influence of microstructure becomes greater and continuum modelling approaches become less accurate. Modelling deformation of the microstructure using crystal plasticity finite element modelling (CPFEM) allows predictions of anisotropic deformation and damage to be made.
A continuum modelling approach is already being used in the Prosperity Partnership; however, combining CPFEM with continuum deformation models for small scale mechanical tests such as small punch and shear compression will allow a more accurate evaluation of micromechanical behaviour. These models can then be applied to larger scale deformation processes such as rolling using a multiscale approach which can then be applied to larger scale deformation

The primary aim of the project is to develop a CPFEM model for specific grades of steel. The model will be validated against small scale test data, using a multiscale approach based on representative volume elements (RVEs) with microstructural data such as grain and phase morphology. This approach will be used to predict damage in small scale tests as well as being used to evaluate the evolution of anisotropy during single and multi-stage deformation. The aim will be to ultimately apply the model to different sized rolling geometries, allowing predictions of the effects of scaling up the rolling processes. Initially the model will be applied to deformation at ambient temperature, with scope to extend to higher temperatures later. The multiscale approach will complement continuum models being developed as part of the Prosperity Partnership.