MANUFACTURE OF THIN COMPOSITE STRUCTURES BY THE RTM PROCESS - NUMERICAL-SIMULATION OF THE SHAPING OPERATION

The glass-fibre preform shaping process is the first stage of the RTM manufacturing process for the production of thin fabric-reinforced com posite structures. A numerical tool for the simulation of this shaping process is proposed. The aim of the software developed is to be able to determine if a drawing operation is possible before the manufacturi ng of expensive tools. The approach used is a mechanical one. The beha viour of the flat fabrics used in the shaping process is obtained from the tensile curve of a single yarn and the current position of yarns during the shaping operation. Discrete finite elements made of yarns a re used, which lead to a good numerical efficiency, especially in the case of elements directed by the yarns. A set of comparisons between s haping simulations and experimental results proves the validity of the proposed formulation. (C) 1996 Elsevier Science Limited