| 摘要 |
PURPOSE:To prevent concentration of stress to a branched part, by a method wherein a structural material composed of main and branched beams made of fiber-reinforced resin is molded by branching a continuous fiber bundle impregnated with resin at a predetermined position while the same is being wound round a winding form and giving a cross-sectional form having a major and minor axes by tightening up a part of the branched beam prior to thermal cure of the structural material. CONSTITUTION:A fiber bundle composed of a carbon fiber is wound round a winding form 4 after impregnation of the carbon fiber with an epoxy resin liquid. Three-dimensional structural material 8 which is composed of a main beam 1 in a parallel direction with an axial line of a center bar 5 and is in a triangle cross section is molded. When the resin is made to cure by a method wherein a mold 9 composed of a top and bottom forces 9a, 9b is set in a form placing a branch beam 2 between the forces at a position close by a branch part A of the beam 2 between the forces at a position close by a branch part A of the branch beam 2 and the structural material is heated under a state that the same is kept as it was, an oval cross-sectional form is given to the structural material in an X-X direction of a part B which has been placed between the mold 9. When external force F is applied to the branched beam 2, it follows that stress does not concentrate to the branch part A by deforming the branched beam 2 through a deformation at the part B where the cross-sectional form has been made to change. |
