A novel approach for fiber placement trajectories and fabric draping in CAE

The definition of the fiber placement trajectories or the determination of the draped fabric configuration is an important step in the analysis of a composite part. In this paper, we study the efficiency of applying the numerical simulation of a moving interface to the problem of defining fiber placement trajectories for composite structures. This new approach is based on the Fast Marching Method. It has two main advantages: first, it simulates the mechanism of an Automated Fiber Placement machine by producing equidistant fiber courses, without undesirable gaps or overlaps between the successive courses; secondly, this method is very general and can be easily applied to complex surfaces, as it works directly on a mesh of the composite part and not on its representation by geometric equations. The method is extended here to deal with the draping of fabrics on surfaces which may be non-developable. The method is then able to identify zones with large shear due to the fabric deformation resulting from the draping process. This approach is illustrated through examples from real case studies for straight and curved fiber placement trajectories, and is compared to finite element solutions in the case of a fabric draping.