The Application Of Multiscale Implicit Finite Element Method In LCM Process Simulations

Liquid composite molding (LCM) technology is a high-powered and cost-effect-ive fabrication technique appearing in recent years.The key technology which can product efficiently stable performance composite materials is to select appropriate process parameters in order to improve the infiltration of resin. However, it will cause a high cost and much difficulty if the parameters are optimized only with the LCM experimental methods.Thus, the design based on numerical simulation becomes a good choice to overcome above difficulties.Multiscale implicit finite element method proposed in the paper improved the traditional implicit finite element method by constructing multiscale basic functions. Because this method do not need divide control volume unit and there is no strict restriction on time steps, we can more reasonably analyze molding transient process, at the same time, the solution of coarse scales can capture fine scales features by constructing the multiscale base functions.lt can overcome the shortcoming of traditi-onal implicit finite element method.The shortcoming is huge computation in order to obtain high computational accuracy.The main work in this paper are as follows:(1)The paper improved traditional implicit finite element method.The mutiscale basic functions used in the paper are constructed by solving the local equation.Thus, the functions will contain micro-scale information, which are reflected in the macro-solution.(2)The multiscale implicit finite element method revised the filling coefficient to ensure the filling coefficient in [0,1].(3)In the paper,we took resin flow through fibers as the movement of a Newtonian fluid in porous media flow.On the basis of resin flow model in LCM process,we gained the finite element numerical formula by multiscale implicit finite element method and wrote simulation program of resin flow process.(4) We simulated the resin flow in LCM process by multiscale implicit finite element method and traditional implicit finite element method respectively, and compared the results with two methods.We research the influence on the amount of injection port and fill time.We observe that multiscale implicit finite element method can forecast effectively stress distribution and resin flow front position.In addition, the multiscale implicit finite element method has high accuracy. The multiscale implicit finite element method is a new method for molding parameter optimization, mold design and ensure product quality.We can observe that it can shorten obviously fill time by increasing injection port.