To address the ongoing efforts to virtually design complex composite materials and their high-perfor-mance structures and to contribute to the increasing developments towards Industry 4.0, research and development of fiber-reinforced composites is shifting from an experimental domain to a virtually con-trolled environment. Material models to account for the specific failure mechanisms of layered fiber-reinforced materials have been developed and can be used for largescale numerical structural simula-tions. However, these models do not account for the individual properties of the reinforcing materials and therefore lack information on microstructural effects and behavior.
LS-DYNA® provides an ever-increasing portfolio of material models covering a wide range of material behavior for solving multi-physics problems. The software also provides users the opportunity to implement their own user-defined material models via FORTRAN code, to describe the behavior of very specific materials. In this work, a user-defined material model has been developed to describe the compression molding behavior of sheet molding compounds (SMCs). A SMC is a composite material based on a thermoset resin reinforced by chopped long fibers. During the compression molding of SMCs, very complex material behavior involving elastic compaction and plastic flow (depending on material composition) occurs, which is dependent on the local fiber orientation, temperature and strain rate. One way to describe the processing behavior of SMC materials as simply as possible is using a building block approach. Following the identification of the most relevant material effects, individual building blocks are created containing the respective mathematical solutions (e.g. compaction and plastic flow behavior).
In recent years, advanced material models have emerged in finite-element codes for the simulation of composite materials reproducing realistic failure mechanisms. Through the increased reliability in simulation, less conservative designs of composite structures have been made possible. However, most of the current numerical solutions are considering the composite material independently of real manufacturing conditions, which can strongly affect the local material architecture and properties. To extend the potential of composite structures, it is therefore necessary to enhance the simulation models by including additional information from the production processes. To answer this problematic, many works have focused on the detailed simulation of these processes and on the transfer of information between the simulation steps [1, 2].
The interaction between textile and soft material occurs in different areas. It can be found in the clothing, medicine or automotive sector. In this paper the textile-soft material interaction has been investigated using the example of the breast-bra interaction. 4D scan data of a test person dressed with a bra and unclothed were acquired in two scan poses. The scans were analysed by cross section comparisons. A finite element model was developed from these scans. Three different meshing methods were modelled. A FEM model of a bra compressing the female breast was successfully developed. The breast deformation is modelled the best with a solid body model. In the validation comparison of the modelled breast deformation and the original breast deformation, a very good agreement can be seen.
Modeling composite materials with respect to reinforcement textile construction