摘要 |
A fiber-reinforced plastic joined body is provided, in which a fiber-reinforced molded article (X) containing carbon fibers and a thermoplastic resin and having a joining surface (x), and a thermoplastic resin member (Y) having a joining surface (y) are welded via the joining surfaces (x) and (y) by applying ultrasonic to the molded article (X), and in which:
(1) a maximum value of tan δ by viscoelastic measurement of the molded article (X) is less than 70% of a maximum value of tan δ by viscoelastic measurement of the thermoplastic resin contained in the molded article (X) within a range of a glass transition temperature ±100° C. of the thermoplastic resin contained in the molded article (X),(2) at least one of the joining surfaces (x) and (y) has an energy director, and(3) an application surface of the molded article (X) to which ultrasonic sound is applied is smooth. |