In this study, ultrasonic vibration was applied to the mold during the hand lay-up molding process to promote resin impregnation into reinforcing fibers and to reduce residual voids. Special mold capable of applying high-intensity vibration was developed, and the effect of ultrasonic vibration on mechanical properties of the molded plate is investigated. Video camera monitoring shows that the time required for resin impregnation decreased under vibration-assisted molding. In acoustic emission (AE) measurements, the specimens molded with ultrasonic vibration showed a delayed onset of initial damage in the case of cross-ply fabric. Cross-sectional observations also confirmed that ultrasonic vibration could reduce unimpregnated regions and residual voids in the molded plates with cross-ply fabric.
Kotani et al. (Wed,) studied this question.