Multiscale modeling of the anisotropic elastic-plastic behavior of paper

• Applicant: Professor Dr.-Ing. Jaan-Willem Simon
• Subject Area: Mechanics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 457025480

Although paper has been used for around 2000 years in numerous applications, the modeling of paper behavior is still not sufficiently researched. There is an increasing demand for simulation tools that can both efficiently compute structural behavior and optimize material properties. The challenge in modeling lies in capturing the influence of the material's underlying microstructure, which consists of an unstructured fiber network, on the macroscopic structural behavior of paper layers. The proposed project aims to develop a numerical modeling strategy that enables an efficient description of material behavior at the structural level while simultaneously capturing the effects at the fiber and network scales. This approach will help answer open questions regarding the influence of individual micromechanical properties and effects on the overall behavior of paper, which are difficult to analyze experimentally due to the small dimensions of individual fibers. In the previous project phase, representative volume elements (RVEs) for fiber networks were created and thoroughly analyzed under various loading conditions. Particular attention was given to the variance in the effective overall response of the RVE due to statistical distributions of geometric data, such as fiber lengths, as well as the material behavior of individual fibers and fiber-to-fiber bonds. These RVEs were implemented using an FE2 methodology based on the finite element method (FEM). The goal of the current follow-up proposal is to validate these FE2 calculations and to make them more efficient by applying model reduction based on the Proper Orthogonal Decomposition (POD) method. This will allow the computation of practically relevant problems that would otherwise be difficult to address due to the high computational cost.

• DFG Programme: Research Grants
• International Connection: Austria
• Co-Investigator: Dr.-Ing. Johannes Neumann
• Cooperation Partner: Professor Dr. Ulrich Hirn