Needle Design for Piercing Uncured CF-SMC: Numerical Model and Experimental Validation

The integration of automation into the Compression Molding process for mass production of automotive components using Carbon Fiber Sheet Molding Compound (CF-SMC) represents a significant improvement in the sector. It improves efficiency, precision, and safety while reducing production costs and allowing product customization. A review of current technologies highlights the limitations of manual lay-up and the potential of automated pick-and-place systems to transfer uncured charges from the preform stage to the mold. Needle grippers have emerged as the most suitable solution to minimize the retention time of composite material in the heated mold, reducing the risk of premature curing. This study proposes a validation model to analyze the needle insertion process, which includes the piercing, detachment, transfer, and release phases, with the goal of developing a numerical model capable of accurately replicating real physical behavior. Focusing on the piercing phase, the analytical model identifies key design parameters that correlate the insertion force, the tilt angle, and the geometry of the needle and the CF–SMC. Subsequently, a hybrid FEM–SPH numerical model, known for its suitability to simulate large-deformation problems, was then implemented in Abaqus. Finally, custom experimental setups and a dedicated picking layout were developed to conduct a preliminary validation of the model, allowing correlations between interaction forces and design parameters.