Simulation of non-isothermal filling process in vacuum assisted compression resin transfer moulding process

Abstract

A non-isothermal filling process of vacuum assisted compression resin transfer moulding (VACRTM) has been developed to reduce cyclic period in this study. In VACRTM, the state of the fabric stack is controllable by stretchable film. During infusion, the resin is isothermally infused into the loose fabrics. After that, a hot fluid with high pressure is applied on the film to heat the resin and compact the preform. A one-dimensional flow and two-dimensional heat transfer model coupled with preform deformation is numerically analysed to investigate the influences of various scenarios on the non-isothermal filling process. Results show that the effects of pressure and temperature distributions at the onset of compression stage are transitional. The main mode of heat transfer is conduction in the thickness direction. Through evaluation of various scenarios, a preferable method is proposed by integrating the concept of fully wetted preform, less excess resin, hot compression and two-sided drainage.

Dynamic pressure control in VARTM: Rapid fabrication of laminates with high fiber volume fraction and improved dimensional uniformity

“…Moreover, the distribution medium usually causes texture on the laminate surface, which may significantly decrease laminate quality . Resin flow can also be manipulated by either relaxing the preform to increase its permeability or forming flow channels using external vacuum chambers . Even though these methods enable faster impregnation, rapid and uncontrolled resin flow may lead to excess resin intake and, thus, reduce the fiber volume fraction of the fabricated parts .…”

“…Even though these methods enable faster impregnation, rapid and uncontrolled resin flow may lead to excess resin intake and, thus, reduce the fiber volume fraction of the fabricated parts . Limiting the resin intake followed by compressing the impregnated preform with an external pressure as in vacuum‐assisted compression RTM (VACRTM), could reduce both the fill time and laminate thickness . Nevertheless, the favorable effect of these rapid filling methods on the laminate properties and microstructure has not been analyzed in detail.…”

Nonisothermal simulation on pressure during resin transfer molding

“…proposed a mathematical model of two‐phase flow in RTM filling stage and realized the numerical simulation. Chang proposed a nonisothermal for one‐dimensional flow/two‐dimensional heat transfer mathematical model for the nonisothermal VACRTM and realized numerical simulation by finite difference method. From literature above studies have been on nonisothermal RTM process with focus on the methods of nonisothermal RTM numerical simulation.…”

Optimization method to select temperature based on chemorheological and exothermal reaction of RTM

“…used numerical simulation to explode the two‐phase flow in the RTM filling stage. Chang proposed a nonisothermal simulation and used it to research the vacuum‐assisted compression RTM process. The aforementioned studies are focused on the methods of nonisothermal RTM numerical simulation.…”