Kinematic Description and Shape Optimization of UD-Tape Reinforcements Manufactured with a Novel Preforming Process

Abstract

The preforming of UD-Tape reinforcement structures for thermoplastic components can be done in additional process steps or during the handling processes. For an efficient process chain, it is desired to avoid non value adding steps like handling. Therefore they should be combined with value adding steps. A novel process for the preforming of UD-Tape strips has been developed at wbk Institute for Production Science to achieve this. In this process, the strips will be locally heated and bent by an industrial robot as they are pushed out of a material supply unit. With the process, it is possible to efficiently preform complex reinforcement tapes without the need for component specific tools. However, the limitation to local bending deformation sets process limitations different from the present, shear based processes. In this paper, an approach to the kinematic description and shape optimization of reinforcement patches is presented. First, a syntax for the description of tape strips containing several bends is presented. Afterwards, the kinematics of the process of bending tape strips around a bendable hinge are described. A method for pre-processing the geometry data of the desired structure with the aim of limiting the solution space is presented. Based on the kinematic description and the preprocessing of the geometric data, a genetic optimization environment for the bending parameters of a tape strip is implemented. The performance of the optimization shows its potential although the specific optimization parameters still have to be improved. Results and limitations of the optimization approach are presented.