| 摘要 |
End portions of face plates 21 and 22 of a hollow extruded frame member 20 are connected by a rib 24 and are welded to end portions of face plates 11 and 12 of a second hollow extruded frame member 10 by friction stir welding. A surface of a connection portion of the end portion of the face plate 21 and the rib 24 is constituted by circular arcs 31 and 32 which are recessed in the hollow extruded frame member 20, and similar a surface of a connection portion of the end portion of the face plate 22 and the rib 24 is constituted by circular arcs 33 and 34. The diameter of the circular arcs 31,33 is smaller than the diameter of the circular arms 32,34. Accordingly, a structure body having a light weight can be obtained, which is able to absorb stress in the friction stir welding. <IMAGE> |
