A NONLINEAR CONTROL METHOD FOR RESIN TRANSFER MOLDING

In performing permeability measurements on the fiber reinforced prefor ms typically used in the resin transfer molding (RTM) process. two typ es of fluid injection are commonly utilized: constant fluid pressure a nd constant fluid flow rate. The constant pressure condition is often enforced by placing the test fluid within a pressure pot. and supplyin g a constant gas pressure, thereby forcing the fluid into the mold und er a constant pressure, in the case of constant fluid flow rate, the f luid is often supplied by forcing a piston through a fluid-filled cyli nder at a constant rate of displacement through the use of a press or Instron machine. This paper presents a nonlinear control method far pr oviding constant flow rate RTM processes with a pressure pot solely th rough the use of a regulator. Computer simulations of the control exam ined the effect of various parameters on the ability to maintain const ant flow rate, Rectilinear now experiments were carried out to evaluat e the theoretical development, Experimental results are in good agreem ent with the computer simulations, Both computer simulations and exper iments show significant promise for the proposed control methodology.