In a collaboration project with Blackwave, the Simutence virtual process chain for SMC materials has been validated for the rim of a lightweight airplane.
Simutence uses an in-mold characterization approach to accurately characterize both the viscosity and the wall slip of the SMC. The acquired data is used to parameterize flow models built into commercial molding simulation software, such as Moldflow.
There are a variety of different approaches for SMC molding simulation. In a collaboration project with Volkswagen (VW) and the Karlsruhe Institute of Technology (KIT), different molding simulation tools have been benchmarked for a honeycomb structure. Therefore, the prediction accuracy for the press force and the filling pattern was validated against experimental tests.
In this case study, a molding simulation for GMT materials is presented. The considered material is TEPEX® flowcore 102-RGR2400/47%, a GMT with an engineering polymer, i.e. PA6, which is manufactured by Lanxess, Bond Laminates.
The results originate from a collaboration project between General Motors Research & Development, the University of Western Ontario (UWO), and the Institute for Vehicle System Technology (FAST) of the Karlsruhe Institute of Technology (KIT) and have been published previously by Dörr.
The 3D skeleton winding (3DSW) technology uses injection overmolded fiber skeletons. The amount of continuous fibers is reduced drastically by using load path-appropriate fiber skeletons. In combination with an optimized overmolding structure cost-efficient lightweight structures are achieved. A CE-certified winding cell as well as a virtual optimization and validation approach for 3DSW structures have been developed in the Korean German ZIM project ACCORD.
SimuWarp was benchmarked in a collaboration project with the Robert Bosch GmbH. Material cards for different materials have been generated and the results of warpage predictions were correlated to experimental tests. A good agreement between simulation and experiments proves the prediction accuracy of SimuWarp.
The prediction accuracy of SimuDrape for the prediction of manufacturing defects in thermoforming simulation was validated thoroughly. This included a comparison of a fully-coupled thermomechanical analysis including the prediction of crystallization kinetics over a purely isothermal thermoforming simulation, showing a high prediction accuracy, especially for the thermomechanical approach.
A sequential approach consisting of thermomechanical thermoforming simulation using SimuDrape and subsequent overmolding simulation in Moldflow was developed. This enables us to predict the temperature field during thermoforming and to consider it during overmolding simulation. A sensitivity study reveals that the temperature in the blank is sensitive to the temperature achieved in the overmolding interface and thus is critical for the interface strength.
The highly specific characteristic for SMC materials is the so-called plug flow during molding, which originates from a thin lubrication layer at the tool-charge interfaces. Here, it is important to know, that this characteristic differs completely from long fiber-reinforced thermoplastics (LFT), which shows a so-called fountain flow. Thus, modeling techniques developed for LFT molding can’t be directly applied to SMC molding, due to the differing flow mechanisms induced by the tool-charge interaction.
Continuously fiber-reinforced polymers (CoFRP) offer high weight-specific material properties, making them well suited for lightweight applications. To achieve a high level of lightweighting, optimization strategies need to be integrated into the design workflow.
The manufacturing costs of a hydrogen storage system using fiber-reinforced composites depend strongly on the amount of carbon fiber used. Therefore, high utilization of the used composite material is important for a successful storage system development. This can be achieved by a fully virtual product development, where each development step is supported by simulation methods.