A macroscopic model of the compaction process during compression molding of carbon fiber sheet molding compounds

Modeling the compressive behavior of carbon fiber sheet molding compounds (CF-SMC) during processing can be a difficult task. This is due to the pronounced porosity of SMC materials, which cannot be adequately reproduced by currently available compressibility models (also called pvT models). Consequently, a macroscopic non-isothermal compression model was developed in this study, which is easy to evaluate and suitable for numerical compression molding simulations. Furthermore, a pvT dilatometer was developed to measure the compressibility of an industrial CF-SMC material. The compression model was calibrated with the measured data and implemented in a commercially used compression molding simulation software. The analytical model accurately describes the compaction behavior of the CF-SMC and its applicability in numerical simulations has been demonstrated.