Abstract
SMC composites, which consist of chopped strand glass mat and resin layers, have been used for structural parts such as transportation vehicles, water tanks, bathtubs and many other applications. When considering the final SMC composite product, the deformation and flow behavior in the molding should be investigated in detail. The main problem is the slippage between inter- and/or intra-layers. Generally, it occurs in laminated materials. Therefore, in this study, finite element analysis was performed to understand the fundamental behavior of the slippage flow in the molding of the SMC. In the FEM analysis, three-dimensional solid elements with a non-linear incremental deformation were employed. A critical shear strain criterion was also employed at the initiation of the slippage. It is the specific value of the shear strain difference at upper and lower of the element to describe the slippage flows between layers.
Fresh inner layer contacts the die surface after slippage flow occurs, technically, this results in a good surface appearance which is the most important characteristics for SMC moldings. The reason is that the non-cure inner layer appears the surface of moldings. Effective usage of slippage deformation/flow can create new high quality SMC products. Thus concept was valified by both experimental and numerical results.
