​Seminar on Physically-based constitutive models used as bridging elements for use in simulations of large scale industrial processes

The talk describes an approach for material modelling applicable to finite element models of industrial scale applications. In such models, the evolution of thermal and mechanical stresses often has to be computed very accurately, and this requires appropriate constitutive relations.

The paradigm of Integrated Computational Materials Engineering (ICME) aims at being able to quantitatively relate process-structure-property of a material. This presentation describes physically-based models, denoted bridging elements, which are one step towards the vision of ICME. They are able to couple the material structure with heat capacity, heat conductivity, thermal and transformation strains and elastic properties for metals. The chemical compositions of the material and its processing are accounted in the models, i.e. thermo-mechanical history, the evolution of the microstructure and the corresponding properties. Hypo-eutectic steels are in focus, but the models are not limited to this group of materials. The models are based on physical variables, i.e. measurable variables characterizing a representative volume element in each integration point of a finite element mesh. In some respects, these models have a natural coupling with microstructure models. Therefore, it is not necessary to resolve the microstructure spatially by the FE mesh.  In addition, some simple examples will be presented.

Dr Jonas Edberg is a Senior Lecturer at Luleå University of Technology (LTU) and has been working with various research issues since 1985. He received his MSc degree in Applied Mechanics in 1985 and got his PhD degree in 1996 at LTU. During the years 1985 – 1998, he also worked as a research engineer at Mefos Metal Working Plant in Luleå Sweden (called Swerim today). Then he worked as a specialist on technical computing at Sun Microsystems with a much broader set of applications between 1998 and 2009. After that, he joined LTU as a research engineer and now as a senior lecturer since 2011. The work at LTU is focused on teaching and research about numerical simulations of metalworking operations and welding, including modelling of defect generation during these operations.