Development of CAE for predicting stiffness of SMC structure: Estimation of Young’s modulus in rib part

Sheet moulding compound (SMC) products have some ribs to improve the stiffness of structures. So, because of the ribs, fibre distribution and orientation in ribs change, and the expected stiffness of products cannot often be obtained. In these cases, while it is needed to change die design, it costs greatly to do so. Therefore, CAE system to improve the efficiency of die design is needed. By the way, stiffness of SMC products in compression moulding is influenced by moulding conditions, especially material flow. However, material flow of SMC is complex and unsteady. In ribs, it is difficult to predict material flow, fibre distribution, fibre orientation and so on. Therefore, it is useful to apply the database that can express these factors simply. We are trying to construct the CAE system to predict the stiffness of structures in SMC compression moulding. In this paper, we investigated the mechanical properties in rib part of SMC products. From the results, we constructed the method for estimating Young’s modulus in rib part in consideration of heterogeneity as fibre orientation, fibre distribution and resin-rich part. Consequently, in predicting Young’s modulus in rib part, we get good agreement with the values by experiment and this system.