Flow front prediction method of non-isothermal resin transfer molding based on mid-plane model

Abstract

The invention provides a flow front prediction method of non-isothermal resin transfer molding based on a mid-plane model, comprising the following steps: (1) constructing a node three-dimensional control volume by a die cavity mid-plane grid; (2) setting molding technological parameters; (3) setting material parameters; (4) calculating resin flowing pressure and speed; (5) calculating resin solidifying reaction; (6) calculating the temperatures of resin and fiber reinforcements; (7) updating flow front and material physical properties so as to ensure time step; (8) ensuring whether the die cavity is filled, and entering the step (9) if the die cavity has already been filled, or entering the step (5); and (9) predicting the distribution of dry spots. Based on the mid-plane grid, the three-dimensional control volume is constructed and the finite element method of the control volume is used, the changes of viscidity, speed, temperature, curing degree and the like in the thickness direction and the influence to the calculation of pressure field are considered in the calculation, and the flow front of resin transfer molding and the distribution of various physical quantity fields can be predicted more accurately.

Description

technical field [0001] The invention belongs to a computer numerical simulation method, in particular to a method for predicting the flow front of a non-isothermal resin transfer molding based on a mid-plane model, which is used for non-isothermal resin transfer molding of a composite product whose size in the plane direction is much larger than that in the thickness direction forming. Background technique [0002] Resin Transfer Molding (Resin Transfer Molding, RTM) is a process of injecting resin into a closed mold to infiltrate reinforcement materials and solidify them. It is also one of the important methods for producing high-quality fiber-reinforced composite products. Compared with the hot compression molding process, the RTM process has less investment in molding equipment, and the production is green and environmentally friendly. Compared with the traditional hand lay-up process, the RTM product quality is stable and releases less harmful volatile substances, and th...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a method for predicting the flow front of non-isothermal resin transfer molding based on the mid-surface model, to solve the problem that the numerical simulation method of the non-isothermal RTM process in the prior art adopts the finite difference method in the thickness direction, and only Considering the change of temperature in the thickness direction, the change of other physical quantities (such as velocity, viscosity, curing degree, etc.) The technical problem of low numerical calculation accuracy caused by only using the first-order upwind style in the direction of the mid-surface grid plane

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