Prediction of the resin fillet size in honeycomb sandwich structures by co-cure process

The resin fillet plays an important role in the bonding performances of co-cured honeycomb sandwich structures by hot pressing process. The numerical method based on resin flow-fiber compaction was developed to predict the resin fillet size under different processing conditions in this paper. The amount of adhesive weight for forming resin fillet was calculated respectively according to the decrease of the thickness of skins and the increase of fiber volume fraction. Processing parameters, including temperature and pressure cycle and the viscosity of matrix resin in prepreg were analyzed by the numerical method. The maximum error is less than 10% which shows that the predictions have a good agreement with the experimental results. The results also show that pressure factors influence the resin fillet size more significantly than temperature factors. This research provides a promising way to predict the forming quality of honeycomb sandwich structure composite and guidance for the optimization of process conditions and control of processing quality.