Permeability Prediction Of Textile Preform And Mold-filling Simulation In Resin Transfer Molding

Resin Transfer Molding,(RTM) is widely used in aerospace, shipbuilding,automotive industry and other fields because of its advantages such as high damage tolerance and high successful rate of finished products. The mold-filling is a key part of RTM and technological parameters in this part can also influence the quality of final products. At the present, parameters of RTM simulation usually use the trial-and-error method, which can easily cause high cost, low effect and the other defects. This paper has studied the RTM mold-filling and designed the mold-filling simulation system that can effectively reduce cost, designing period, and also improve the rate of finished products.In this paper, a mathematical model of meso flow is set up based on analyzing the RTM mold-filling. Human-computer interaction model, building geometry of preform model, permeability prediction of preform model, mold-filling simulation model and the experiment validate model are included in the RTM mold-filling system. According to analyze all the five models and the simulation process of this system, a overall scheme of the system is established. And then, a multi-level architecture and a technology solution of permeability prediction are built.Permeability of preform is one of the key technological parameters of RTM mold-filling simulation. In this article, a mathematical model that can both objectify resin meso flow between adjacent yarns themselves and resin micro flow in yarns is established at first. And then geometry models of preform cell under different states are established. By simulating and analyzing the permeability of preforms under different states, some relevant solutions that permeability decreases with the increment of the compression can be acquired. By experimental measurement and data analysis, the geometric models and forecasting method are proved to be correct.A method of simulation for RTM mold-filling is studied based on the VOF method. And then a two-dimensional numerical example verifies the accuracy of this method. The unsaturated flow mathematical model is set up by introducing the sink function in control function. Unsaturated flow is numerical calculated by a method,which combines the master-slaver element with finite element/control volume method. In this article, unsaturated flow is simulated based on the algorithm,which combine the VOF with sink function introduced by UDF. Finally,numerical example shows the feasibility of the algorithm.Based on platforms which use to build models, calculate and manage data, a system of RTM mold-filling can be developed. In this system, the relevant functionmodules are designed and implemented. In the article, the practicability and correctness of the system are verified by simulating the flange model.