Method of manufacturing ribbed structure by using biodegradable mold

A method of manufacturing a ribbed structure with fiber-reinforced composite material, the ribbed structure including a T-shaped cross section having a wide head portion and a narrow body portion, comprising:

• preparing a reference surface mold which has a reference surface and a wide head portion-formation groove for formation of the wide head portion, formed in a predetermined position in the reference surface;
• preparing a mold for the ribbed structure, located in a predetermined position on the reference surface of the reference surface mold, providing a narrow body portion-formation groove for formation of the narrow body portion of the rib in association with the wide head portion-formation groove, and having a mold surface;
• forming a mold for the narrow body portion of the rib by using a material containing biodegradable polymers;
• placing non-hardened resin containing reinforcing fibers in the wide head portion-formation groove formed in the reference surface of the reference surface mold;
• placing the structure mold in a predetermined position on the reference surface of the reference surface mold;
• laminating non-hardened resin containing reinforcing fibers on the mold for the narrow body portion, and then placing the mold for the narrow body portion in the narrow body portion-formation groove provided by the structure mold placed in the predetermined position on the reference surface of the reference mold;
• placing non-hardened resin containing reinforcing fibers on the mold surface of the structure mold to cover the non-hardened resin containing the reinforcing fibers on the narrow body portion mold in the narrow body portion-formation groove;
• hardening all the resins;
• and
• biochemically degrading the narrow body portion mold,
• wherein the reference surface mold end the ribbed structure mold are formed using a material containing biodegradable polymers, and are biochemically degraded along with the narrow body portion mold;
• and
• wherein in the hardening of the resins, the resin hardened in the wide head portion-formation groove, the resin hardened on the narrow body portion mold, and the resin hardened on the mold surface of the structure mold are united with each other.