Abstract:
Mould tools used for LCM processes such as Resin Transfer Moulding (RTM) and Injection/Compression Moulding (I/CM) must withstand the forces applied during compaction of the preform and injection of the resin. A simulation package has been developed at the University of Auckland to predict the forces applied to moulds during these processes. This will allow cost effective mould design and process selection. The simulation package utilizes a viscoelastic compaction model, which has been characterized for a glass-fibre chopped strand mat. Several RTM and I/CM experiments have been carried out, the local stress distribution being monitored throughout, as well as the total clamping force applied to the mould. The influence of the fluid pressure on the total stress experienced by the mould is shown to be a function of both the fibre volume fraction and the injection pressure, the latter being more pronounced at low volume fractions. The stresses observed during I/CM are significantly higher than during RTM, however the process times for I/CM are considerably lower. These experiments have been compared to initial calculations performed with the LCM simulation, and good agreement has been shown for the normal stress distributions and total clamping force evolutions recorded.