To provide a three-dimensional fiber structure consisting of fiber reinforced composite material having a structure of a cylindrical shape with bottoms whose mechanical characteristic is excellent and can be easily estimated and suitable for frame materials.
In this three-dimensional fiber structure W formed into a cylindrical shape with bottoms, the cylinder part 2 and bottom parts 1 are composed of laminated fiber groups 3 having a pseudo isotropic orientation formed by laminating plural fiber layers consisting of fiber bundles F arranged in specific directions. The laminated fiber groups 3 are bound with thickness-direction yarns arranged in the direction perpendicular to each fiber layer. A bottom part 1 is constructed into pseudo isotropy with fiber bundles F arranged in three directions of +30°, -30° and 90°. The cylinder part 2 is constructed into pseudo isotropy with fiber bundles arranged in four directions of 0°, +45°, -45° and 90°. The fiber bundles F arranged in the bottom part 1 are connected to fiber bundles F arranged in the cylindrical part 2.
YASUI YOSHIHARU
SUZUKI KOUYA
