Coupled non-conforming finite element and finite difference approximation based on laminate extrapolation to simulate liquid composite molding processes. Part II: non-isothermal Filling and Curing

A numerical methodology is presented for the accurate simulation of non-isothermal mold filling in Liquid Composite Molding. Starting with a mid-surface mesh and based on the structure of the fabric reinforcement, the extrapolation algorithm described in /17/ is used to generate 3D finite elements or parallel layers of 2D elements. To solve the coupled flow/energy/chemical species equations, two methodologies are used. The finite element formulation presented in /17/ is first coupled with a 3D finite element formulation for heat and curing analyses. In the second approach, a hybrid finite element and finite difference model is proposed. As the heat conduction and convection is evaluated in the plane of the elements by the finite element formulation, the through-thickness heat flow is computed by a one-dimensional finite difference approximation. The combination of the three-dimensional mesh extrapolated in parallel layers with the thermal formulations allows investigating diverse degrees of coupling between the fluid and heat flows. With the same initial 2D mesh and material data, the user can easily define the level of complexity to be used in the numerical model. The results of the thermal formulations are validated with analytical tests. The performance of the model as well as the gain in cpu time are summarized. Finally a test case is presented to illustrate the advantages of the coupled model in terms of accuracy.

Mots clés

liquid composite molding (LCM); composites processing modeling; non-conforming finite element; non-isothermal simulation; mesh extrapolation