ABSTRACT
In a development study of the air-turbo-ramjet (ATR) engine for a space plane, application of carbon-carbon (C/C) composites play an important role to achieve expected performance of the engine. Above all, dovetail joint structures are one of the key structure to realize the turbine structure. From this point of view, a feasibility study for the application of C/C composites to the dovetail joint was carried out in this study.
Tensile tests were carried out on simplified dovetail joint models made of two or three dimensionally reinforced C/C composites. The shoulder angles of the dovetail joint were taken as a parameter to optimize a shape of the dovetail. Finite element analysis was also carried out to obtain stress distribution in the joint. Results suggests that fracture of the dovetail joint is controlled by the average shear stress, which implies shear stress concentration on the shoulder is relaxed during failure process of the C/C composite dovetail. It is also shown that the dovetail joint made of C/C composites is feasible for the ATR engine.
