Optimisation of Sheet Forming for Textile Composites using variable PeripheralPressure.

摘要

This paper addresses optimisation of the sheet forming process for textilecomposites. A woven carbon/epoxy prepreg helicopter pilot helmet is used todemonstrate both experimental and numerical studies. A novel stamp-formingexperimental procedure is developed, where a segmented blank-holder is used tocontrol draw-in, facilitating process control and optimisation. A truss basedfinite element model, incorporating non-linear fabric shear properties and theoccurrence of wrinkling due to tow buckling, is used to simulate forming. Thesimple basis of the model results in low computational times that allow its usewithin an optimization procedure. A genetic algorithm is used to solve theoptimisation problem, minimizing the wrinkling in the formed component byselecting a suitable peripheral holding force distribution. Optimised designsresulting from the inversion procedure have significantly lower wrinkling thanuniform peripheral force profiles.