Optimising high-throughput, automated preform production with non-linear simulation of the pick and place process for technical fabrics

The serial manufacturing of high performance composites parts is based on the lay-up of textile cuttings with subsequent resin impregnation. For industrial applications the cuttings are produced on automated cutter systems [1, 2, 3, 4, 8]. The existing difficulty for a complete automated process is the "pick and place"- process of these cuttings [1, 2, 3, 4, 8]. The process step is a main challenge for high throughput and quality. The textiles have a low stiffness, high sensitivity against mechanical loads and great range of the mechanical properties depending on the fabric structure [5]. The production of high performance parts is dominated by non-crimp fabrics with single- or multi-layer structure. Currently the handling of textile cuttings is done manually. These leads to challenges in the handling process if the cuttings become larger or the handling times have to be reduced for a more effective production [1, 2]. Automated "pick & place" will avoid structural defec ts and speed up the production [1, 2]. Currently handling of textile blanks is dominated by grabbing of the entire cutting surface [2, 3, 8]. More flexibility of such gripping devices can be achieved by multiple picking points with relatively small contact areas instead of the entire fabric area. Apart from the challenge of choosing a feasible gripping principle, the number and the positioning of gripping units have to be known for a successful handling. Because of the different shapes and variation of mechanical properties a practical evaluation will need time and resources. This can be reduced by a virtual model for the handling process. The approach of this work is focussed on non-crimp fabrics. Existing simulation approaches of the handling process are based on the complex modelling of textiles substructure [6, 7]. The proposed solution is based on FEA -approach with existing elements by modelling the integral textile structure. The non-linear FE-model requires a relatively small number of mater