Blank geometry design for preforming of woven composites based on numerical modeling

The prepreg compression molding process has received increasing attention from industry due to its cost-effectiveness and ability to produce complex structural shapes, and the design of the initial blank geometry is critical for the efficient production of woven composite parts using the automated manufacturing process. To design the optimal blank geometry that meets the structure requirements, and minimize trimming and waste of the edge material after preforming in the prepreg compression molding process, a blank geometry design method was developed based on finite element analysis (FEA) of preforming and a modified non-orthogonal material model. Meanwhile, whether normal vectors of all shell elements of the preformed prepregs pointing to one side of the produced structure was analyzed to automatically detect appearance of wrinkles and overlaps. An optimal blank geometry can be designed by modifying edge elements of the prepreg model through iterations of the preforming simulation. By comparing with the experimental results, the blank span length, appearance and yarn angles predicted by the preforming model were validated, and capability of the modeling-based design method to optimize the prepreg blank geometry for minimum material waste during preforming was verified.