NUMERICAL MODELING OF FIBER BUNDLE ARCHITECTURE IN THE ROBOTIC CORELESS FILAMENT WINDING PROCESS

The coreless filament winding (CFW) is a novel robot assisted manufacturing process, where impregnated fiber bundles are wound around sleeves in a defined chronological order. Unlike conventional winding, there is no mandrel available to define the resulting shape. Instead the fiber-fiber and fiber-sleeve interaction, influenced by winding sequence and prestress, is forming the final fiber architecture. Depending on the load case of the subsequent area of application, a precise knowledge on the cross-section of the resulting fiber structure is required for a reliable structural evaluation. In order to enable virtual modeling of the forming process, an expansion-based multifilament method is presented. The values for influencing parameters, such as filament diameter, static coefficient of friction, Young's modulus, pretension and penalty stiffness require a balanced interaction and therefore need to be optimised to experimental results during an optimization loop. To evaluate the deviation between simulation results and experimental data, the area and maximal dimensions in a cross-section of a specimen is used.