ON THE EFFECT OF DRAPING STRATEGY ON FE-BASED DRAPING SIMULATION OF BASIC AND COMPLEX 3D GEOMETRIES FOR AUTOMATED PREFORMING

摘要

Preforming of dry fabrics is a process under investigation for large scale production of carbon fiber reinforced plastics (CFRP). The automation of automotive CFRP parts is motivated by large scale volumes and the need for cost reduction. It is important to understand the critical deformation phenomena of dry fabrics, which occur during the draping of complex geometries, before investing in expensive tooling. A variety of software codes are available to study the effects of deformation during fabric composite forming. Only with finite element (FE) based simulation tools it is possible to study the effect of manufacturing parameters in detail, however they are computationally more expensive than geometrical draping tools. To shorten the computational effort involved in FE draping simulation, the authors study critical shear phenomena on a simplified geometrical level which includes 2.5D and 3D geometries. A previous study using 2.5D geometries revealed the interaction between proper ply placement and tooling directions for a one-piece upper tool for an automated draping process. A transfer of these findings onto basic isolated geometries and complex 3D geometries is used to verify this draping strategy. The strategy under investigation is extended by the influence of tool segmentation on basic 3D geometries. To conclude the work presented, tooling sequences are studied for complex S- and C-shaped geometries, and recommendations are made on how to achieve an optimized drape solution for woven fabrics.