フィラメントワインディングロケットモーターケース形状設計手法に関する一考察

抄録

As solid Rocket motor cases made of carbon fiber reinforced plastic (CFRP) by the use of inplane filament winding method have nonuniform distributions of thickness and elastic properties, their optimum shapes are far different from spheres and must be determined under the consideration of the stress and/or deformation distributions. A design method, where the shape is determined from the strain ratio between the longitudinal and hoop directions, is proposed first. Then, the deformed shape obtained by a finite element analysis, considering a geometrical nonlinearity, is proposed to be used as the dome shape. Deformation and bending stresses of the rocket motor cases designed by the conventional method based on the netting theory and present methods are calculated by the use of a finite element method (NISA II). The shape derived from the nonlinear analysis is found to be an ideal shape which shows much smaller bending stress than the conventional dome derived from the iso-tensoid shape.