Evaluation of Temperature Profiles in Thick Composite Parts during Autoclave Processing

摘要

In autoclave processing, the temperature history of the part is an important factor in determining the acceptability of the process as well as being an important determinant of the residual stresses and final deformation of the part. In this study, as many as 50 thermocouples were used to gather very detailed thermal profiles of thick CFRP composite parts for a variety of cure cycle conditions. The effect of bagging conditions, temperature ramp rate and autoclave pressure on the temperature profiles were investigated. Unexpected but fully explainable effects were seen. For example, bag leaks can have significant effects on thermal profiles, but this effect might be ignored or dismissed if only a few thermocouples are used. A number of lessons learned are presented, including a first attempt at defining best practices for optimization of thermocouple placement and two different methods of back-calculating the heat transfer coefficient of the autoclave.