USE OF A DESIGN AND CONTROL METHODOLOGY TO MANUFACTURE COMPLEX COMPOSITE PARTS BY MANIPULATING FLOW DURING RESIN TRANSFER MOLDING PROCESS

摘要

Previous efforts have done the preparatory work towards the intelligent injection of a prototype part to be made utilizing the Resin Transfer Molding process. The different features of the prototype part such as ply drop-offs, ribs and stiffeners, thick sections, taping sections and changing fiber volume fractions were analyzed separately to see their influence on flow and compared with predictions. In this study, the tool for this study was fabricated that encompassed all of these features. Simulations were performed to predict the resin flow patterns due to disturbances such as race tracking along the edges. A suite of software tools was used to select the sensors that would identify the type of disturbance, and then further decide upon control actions to correct for the disturbance. This information was transferred to a supervisory computer to incorporate the intelligent injection scheme during the experiment. On the experimental side, mold imbedded point sensors and automated pneumatic grippers to open and close any gates or vents were installed. Two injection machines capable of being controlled with the computer were used for the filling. The supervisory computer was used to interface with the hardware and to monitor and control the mold filling experiment. A case study was performed with and without control actions to test whether the control actions can prevent incomplete fillings due to unplanned race-tracking disturbances. It was shown that without control, the disturbed cases caused dry spots (resin starved regions), which the control actions eliminated. The system also demonstrates that we are one step closer towards automating the resin transfer molding process by the integration of modeling and simulation with the hardware such as injection machines, sensors and valves using data acquisition systems.