Prediction of mechanical behavior of spatially reinforced composites for kick motor nozzle

This paper predicts the material properties of spatially reinforced composites (SRCs) and analyzes the mechanical behavior of a kick motor nozzle manufactured from that material. To find the appropriate SRC structure for the nozzle throat that satisfies given design conditions, the equivalent material properties of the SRC are predicted using the superposition of rod and matrix stiffnesses. The kick motor nozzle considered in this study consists of graphite or SRC as the throat part, carbon/phenol as the outer surface of the entrance part and inner surface of the expansion part, and steel as the outer surface of the expansion part. The material properties in arbitrary spatial directions are predicted and compared for 3-D and 4-D SRCs suitable to an axisymmetric kick motor nozzle structure. The 4-D SRC shows the smallest and uniform deformation in the nozzle throat, which has a favorable effect on the rocket thrust. The equivalent material properties of SRC are input to analyze the mechanical behavior of the kick motor nozzle using finite element method.