Fiber-reinforced composite material and sandwich structure

A The fiber-reinforced composite material comprising:

• a resin (A), wherein the resin (A) is a thermoplastic resin;
• and
• a reinforcing fiber (B), wherein the reinforcing fiber (B) is a discontinuous fiber having a number average fiber length of 1 mm or more and 50 mm or less, and including:
• a fiber-reinforced structure portion including an in-plane orientation portion having an average fiber orientation angle of the reinforcing fiber (B) of 0° or more and 45° or less and an out-of-plane orientation portion having an average fiber orientation angle of the reinforcing fiber (B) of more than 45° and 90° or less;
• and
• a tunnel-shaped cavity portion defined by the in-plane orientation portion and the out-of-plane orientation portion of the fiber-reinforced structure portion,
• wherein the tunnel-shaped cavity portion extends in an in-plane direction of the fiber reinforced composite material, and
• wherein the in-plane direction is orthogonal to a thickness direction of the fiber reinforced composite material.