Optimisation of the co-curing of two different composites with the aim of minimising residual curing stress levels

We have established an optimisation procedure for curing cycles with the aim of reducing residual curing stresses in composite laminates. The main goal of this optimisation procedure is to reduce residual curing stresses while keeping the mechanical characteristics of the materials at a maximum level without exceeding a maximum duration of the cure cycle. An optimisation procedure first developed for a single composite material is extended to the simultaneous curing of two different materials. The results of the procedure ale presented as a three-dimensional diagram which allows the determination of optimum temperature conditions to minimise residual curing stresses. Furthermore, this diagram allows us to show that the curing conditions could be defined according to a coherent scheme in order to minimise residual curing stresses while the laminate mechanical characteristics remain constant. (C) 1998 Elsevier Science Ltd. All rights reserved.