Optimization of Parts Placement in Autoclave Processing of Composites

The main processing variable in autoclave production, besides pressure and time, is fluid temperature. The different geometry of tools and composite laminates and the fluid dynamic characteristics of each autoclave batch lead to temperature changes in the composites, during heating, soaking and cooling, not easily predicted. The soak time at maximum temperature is considered one of the most critical constraints. This time is computed for the entire autoclave batch when the last composite laminate reaches the specified cure temperature. In this work a completely different approach is presented. Areduction of cure time is achieved identifying a rule for the position of different tools inside the autoclave. An optimization model is derived by defining an objective function in terms of penalty coefficients associated to different tools and different positions into the autoclave. Test cases of the behaviour of autoclave batches have been simulated leading to significant predicted cure time reductions.