Modeling the influence of liquid environmental media on the mechanical properties of semi-crystalline plastic components using a multiscale simulation chain

• Applicant: Professor Dr.-Ing. Christian Hopmann
• Subject Area: Plastics Engineering
• Term: from 2020 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 433187426

The aim of the research project is to describe the media influence on semi-crystalline plastic components in the context of virtual component design.In their use, plastic components come into contact with a large number of liquid environmental media, which can significantly influence their properties. This influence cannot or only insufficiently be considered in the component design, which endangers the functional performance of highly technical plastic components. The influence of the ambient medium on the material is very diverse and affects different scales. For example, the macroscale effect of a component's loss of stiffness through media contact is influenced by the crystalline structure on the microscale, the chemical composition of the polymer and the sorbates on the nanoscale. Our own preliminary work shows that the influence of a medium on the inherent material properties can be modelled using atomistic simulations for amorphous thermoplastics.Up to now there have been no fundamental investigations in the technical literature regarding the virtual component design of semi-crystalline plastic components under the influence of media, including the consideration of effects on different scales. The planned project aims to fill this research gap. In the proposed project, a multi-scale simulation chain will be used to map the influence of media on semi-crystalline thermoplastics, taking the microstructure into account. For this purpose, an injection molding simulation, to determine the microstructure, is combined with a diffusion simulation, to calculate local media concentrations, and with a structure simulation to map the component load. The necessary material parameters are determined by atomistic simulations (molecular dynamics and Monte Carlo simulations). Both the individual simulations and the entire chain are continuously examined for their imaging quality, whereby the goal of realistically mapping the influence of the media on semi-crystalline plastics is checked.

• DFG Programme: Research Grants