Fabrication, process simulation and testing of a thick CFRP component using the RTM process

The present article introduces the case of a CFRP con-rod beam, and describes many aspects regarding its production with the Resin Transfer Moulding (RTM) process. The objective was to find the best process parameters of the injection and curing stages in order to manufacture the 20 mm thick CFRP part. The results are analysed in terms of the aesthetic aspect, the porosity and the mechanical properties of the final component. For the resin injection stage, results obtained from production experiences are presented, which have been performed with different set-ups, and simulations of the resin flow are used to analyse them. The results show that the resin flow during injection could be rather unpredictable, probably because of the fibre rearrangement and race tracking effects. Improvements in terms of aesthetic aspect and porosity of the part could be achieved by a process which included final compaction of the cavity by means of compressed air. Regarding the curing stage, the article presents the simulation results of a curing cycle, and it’s validation through DSC analysis of specimens obtained from the finished component. Finally, results of tensile mechanical tests are provided, performed on finished components produced by RTM and compared to others produced with the method of hand lay-up of pre-impregnated plies and curing in autoclave (Prepreg + Autoclave). The results confirm that it is possible to achieve components through RTM with comparable mechanical performance to those produced with the Prepreg + Autoclave process.