Fiber reinforced composite material structure, composite material molded body using the same, and manufacturing method therefor

1. A fiber reinforced composite material structure comprising:

a thin sheet that includes a first surface and a plurality of convex portions which protrude and are regularly arranged on the first surface and each of which includes a top face, the thin sheet including a reinforcing fiber; and

a surface material that includes a second surface and is bonded to top faces of the convex portions on the second surface,

wherein the reinforcing fiber in the thin sheet is a sheet-like material in which a plurality of long fibers are arranged in parallel in one direction where the sheet-like material is laminated so that each of the long fibers is aligned in 0° and 90° directions or a fabric formed of a long fiber,

an arrangement of the plurality of convex portions includes a zigzag arrangement in which an arrangement direction of the plurality of convex portions forms an angle with respect to a longitudinal fiber direction of the reinforcing fiber,

the plurality of convex portions include a first convex portion and a second convex portion adjacent to the first convex portion,

a first area is defined by being surrounded by a boundary line between one convex portion among the plurality of convex portions, and the first surface,

a pitch of the convex portions is 1.6 to 2.4 times the minimum diameter of the first area, and

the pitch of the convex portions is defined by the gap between a center axis of the first convex portion which is perpendicular to the first surface and a center axis of the second convex portion which is perpendicular to the first surface.

2. The fiber reinforced composite material structure according to claim 1 ,

wherein in the convex portion among the plurality of convex portions, the shape of the top face of the convex portion and the shape of the first area are at least one shape selected from a square shape, a rectangular shape, a rhombic shape, a triangular shape, a pentagonal shape, a hexagonal shape, a circular shape, an oval shape, a rounded square shape, a rounded rectangular shape, a rounded rhombic shape, a rounded triangular shape, a rounded pentagonal shape, and a rounded hexagonal shape.

3. The fiber reinforced composite material structure according to claim 1 ,

wherein in a second area provided with the plurality of convex portions arranged regularly, the ratio β/α is equal to or larger than 5% and smaller than 40%,

where αand β is the area of the second area and the total area of the top faces of the plurality of convex portions, respective.

4. The fiber reinforced composite material structure according to claim 1 ,

wherein in one convex portion among the plurality of convex portions, the area of the top face of the convex portion is equal to or larger than 5 times and smaller than 500 times of the square of the sheet thickness of the thin sheet.

5. The fiber reinforced composite material structure according to claim 1 ,

wherein the height of each of the plurality of convex portions is equal to or larger than 0.5 times and smaller than 10 times of the sheet thickness of the thin sheet.

6. The fiber reinforced composite material structure according to claim 1 ,

wherein in each of the plurality of convex portions, the minimum Feret diameter in a cross-section parallel to the top face is equal to or larger than 3 times of and smaller than 30times of the sheet thickness of the thin sheet.

7. The fiber reinforced composite material structure according to claim 1 ,

wherein a concave recess is provided in each front end of the plurality of convex portions.

8. The fiber reinforced composite material structure according to claim 1 ,

wherein the arrangement of the plurality of convex portions further includes at least one of a square arrangement in which the plurality of convex portions are arranged at the directions of 0° and 90° with respect to the longitudinal fiber direction of the reinforcing fiber and a rectangular arrangement in which the plurality of convex portions are arranged at the directions of 0° and 90° with respect to the longitudinal fiber direction of the reinforcing fiber.