Coordinator: dr inż. Joanna Szyndler.
Project has been realized under the following hypothesis: development and further application of a multiscale numerical model of plastic deformation process, connected with the digital material representation (DMR), provides a possibility for a detailed analysis of material flow under complex strain states at the microstructure level. Such complex strain states occur in many modern manufacturing processes i.e. incremental or cyclic forming.
Two main scientific goals were defined:
1. Development of the multiscale numerical model, which is based on the
digital material representation approach to describe local material flow
at the microstructure level.
2. Detailed analysis of the material flow at the macro and micro scales
during plastic deformation process, that is characterized by complicated
strain states (i.e. innovative incremental forming process).
Particular attention during the investigation was focused on a research
with a basic character, including analysis of influence of deformation
process parameters on material flow in two dimensional scales: micro and
macro.
Project was divided into two parts: experimental research and numerical simulations. The first, involved plastometric tests (i.e. axisymmetrical upsetting test) realized on the Gleeble 3800 simulator with different strain rate values at temperatures below recrystallization. Results from these experimental tests were used to develop a material model for further numerical calculations. An inverse analysis was used to evaluate appropriate flow stress data. Additionally, series of laboratory tests was made to experimentally analyze material behavior under single and subsequent anvils during incremental pressing. Obtained results provided data on material behavior in the interested zones of the sample and were used for a numerical model validation at the second stage of the project. In this part metallographic analysis was also realized, to obtain images of microstructure for generation of the DMR and to investigate local material behavior at the microstructure level prior and after deformation.
The second part of the project, was focused on numerical research. During this part, the concurrent multiscale numerical model, that replicates basic assumptions of the complex incremental forming process was developed. This model is composed of a conventional macro scale solution connected with the digital material representation micro scale approach. To obtain accurate digital material representations in 2D and 3D scales, methods based on image processing of real microstructure and numerical methods based on discrete approaches (Monte Carlo) were used. During the research conventional material model was mainly used, however to predict changes in texture a crystal plasticity model was incorporated into the DMR. After obtaining numerical results at the micro scale, it was possible to compare microstructure changes with real experimental data, e.g. morphology of deformed grains, to validate the model predictive capabilities. Moreover, detailed analysis of the influence of numerical model parameters on the quality of obtained results was performed.
The main output of the project is the multiscale concurrent numerical model that provided detailed understanding and knowledge on material behavior under incremental deformation conditions both at the macro and micro scales, respectively. This basic knowledge on material flow under the incremental deformation may be used in the future to properly design the manufacturing technology of integral components used in the aerospace industry.
