Method for manufacturing structure using composite material

A method for manufacturing a structure using a composite material having a skin and a stiffener which is a composite material in which fiber layers are laminated in a plate thickness direction, the method comprising:

• a tapering step of forming, with respect to the stiffener having a plate shape in an uncured state that has a first surface which is a flat plate surface and a second surface which is a surface opposite to the first surface, a first tapered surface forming an angle with the second surface;
• a bending step of bending the stiffener tapered in the tapering step so that the second surface is on an inner side;
• an arranging step of arranging the stiffener and the skin so that the first surface of the stiffener bent in the bending step and the skin comes into contact with each other;
• a vacuum suctioning step of covering the stiffener and the skin arranged in the arranging step with a flexible material and performing vacuum suctioning on an inside of the flexible material;
• and
• a joining step of curing the stiffener subjected to the vacuum suctioning step to join the stiffener and the skin to each other,
• wherein in the tapering step, the tapering is performed so that the angle between the first tapered surface and the second surface after the bending is performed in the bending step is an acute angle, and
• in the vacuum suctioning step, the vacuum suctioning is performed to deform the stiffener so that the first tapered surface comes into contact with the skin while maintaining a contact state between the first surface and the skin, and to deform the stiffener so that a second tapered surface having an acute angle with respect to the skin is formed on the second surface.