Method of manufacturing unevenness shaped Z-pin and Z-pin manufactured using the same and composite structure including the Z-pin

A method of manufacturing a Z-pin having an uneven surface used for Z-pinning of a composite material laminated structure, comprising:

• forming a pillar shaped body by an extruding process, the pillar shaped body having a length and a cross-section;
• preparing a gear-shaped press-fitting forming jig having gear teeth formed along a circumference of the gear-shaped press-fitting forming jig;
• pressing and rotating the gear shaped press-fitting forming jig on the pillar shaped body along a longitudinal direction thereof to form an unevenness pillar shaped body having an uneven surface, thereby forming unevenness in a surface of the pillar shaped body by the gear teeth;
• and
• cutting the unevenness pillar shaped body at an inclined angle with respect to the longitudinal direction thereof into a plurality of Z-pins each having the uneven surface and a predetermined length, at least one end portion of each of the Z-pins having a sharp distal end.