Thermal expansion mold design using silicone rubber and processing quality analysis of bidirectional stiffened plates

A thermal expansion process with a closed mold and a silicone rubber assisted autoclave process are both adopted to produce bidirectional stiffened carbon fiber reinforced composite plates. The features of these two processes and their effects on the processing qualities are analyzed. Furthermore, for the silicone rubber assisted autoclave process, the effects of process gap, thickness of silicone rubber and metal mold positioning on the consolidation and dimensional accuracy of the products are studied. The results demonstrate that compared with the thermal expansion process with a closed mold, the silicone rubber assisted autoclave process and its mold design are more suitable for the production of bidirectional stiffened composite plates. The process gap of the thermal expansion process should be designed based on the free-expansion mode of the silicone rubber in the autoclave process. Moreover, the thickness of silicone rubber has little effect on consolidation, while larger thickness results in more obvious unevenness of temperature. The method that holds the metal mold in position in the autoclave process can significantly enhance the dimensional accuracy and consolidation degree at the intersection of ribs. These research results are of significance to the development of control technology on the manufacturing quality for composite grid stiffened structures.