Characterization and numerical investigation of an RTM cure process with CFRP molds and independent heat patches

The knowledge of the temperature development within thick carbon fiber reinforced polymer (CFRP) parts during cure is crucial for the production of high performance aerospace components given that high exothermic temperature peaks may degrade material properties and introduce additional components of residual stress. During cure of CFRP parts with complex geometry and varying cross sections a uniform temperature distribution and hence homogenous material property development is sought. A novel resin transfer molding (RTM) tooling concept, consisting of CFRP mold parts with integrated in situ heating patches, is modelled within a commercial finite element platform (Abaqus) for further cure simulation utilizing Compro/CCA. A mono-component resin system and the tooling material were characterized by means of differential scanning calorimetry (DSC) and NanoFlash^TM tests. Characterized material data was verified by simulative prediction and experimental comparison of a 30 mm laminate coupon during cure. A simulation strategy was developed and implemented to model the transient thermal response of the in situ heating device by modification of boundary conditions via a feedback control system. Finally a typical process temperature cycle has been used to validate the implemented simulation strategy numerically.