Effect of Molding Condition on Mechanical Properties of FRP by RTM (abstract only)

In general, it is considered that mechanical properties of CFRP should be the same if reinforcing fiber and matrix resin, reinforcements and surface treatment were the same whatever molding method was. However, it was revealed that mechanical properties were influenced by molding method. In recent study, propagation of microscopic damage was different depending on the molding method, and microscopic damage of FRP by RTM was likely to occur compared to FRP by hand-lay-up. It was said that difference in interface properties formed by molding method was caused. On the other hand, thermosetting resin composite material have high heat resistance, but long molding time was needed due to the chemical reaction. Therefore, HP-RTM (High Pressure Resin Transfer Molding) using fast cure type resin has been adopted. HP-RTM is a molding method that enables to shorten the molding time by using fast cure type resin pour into the molding die in a high pressure condition. However, the resin is transferred under the condition of high pressure and high speed in HP-RTM, interface property might be declined. The purpose of this study was to restrain microscopic damage by improving interface properties in RTM method. Also, effect of molding pressure by HP-RTM was revealed. After carbon fiber reinforced composite material was molded by changing pressure of HP-RTM, tensile test and observation of microscopic damage were carried out to observe propagation of microscopic damage.