Paper is a versatile material whose applications extend beyond its well-known function as a writing and printing material. For example, it is used as a packaging material in the logistics and food sectors, or in the form of honeycomb structures in furniture. Since paper is based on a renewable resource and is comparatively easy to recycle, it is expected that its importance will soar over the coming years.

Nevertheless, even though paper has been produced and improved in industrial processes over decades, suitable simulation tools for structural calculations are still lacking. One reason for this is that the structural behavior is determined by complex mechanisms on the microstructure. Therefore, the goal of this project is to provide the transfer between macro- and microstructure. A numerical modeling strategy will be developed that provides an efficient prediction of the material behavior on the structural level as well as being able to represent microstructural effects.

According to this modeling strategy, a representative volume element (RVE) of a fiber network is created and incorporated into the FE2 concept. First, the question of the required network size for the RVE is addressed. Furthermore, the effects of statistical distributions of geometric data and material parameters on the effective network response are investigated. This is preceded by the modeling of the individual fiber by a suitable elasto-plastic material model. In addition, the analysis and simulation of the fiber bonds is performed to determine contact parameters for a cohesive contact formulation. The RVE determination is followed by the implementation into the FE2 concept. Therein, the material response at the structural level (macroscale) is determined by means of the network level (microstructure). The final validation of the described modeling strategy using experiments that reproduce characteristic load cases in paper applications is also part of the project.