| 摘要 |
PROBLEM TO BE SOLVED: To provide a light and highly rigid structure. SOLUTION: Two face plates 21, 22 are joined with each other through ribs 23A, 23B in a truss to form a hollow shape. An end part of one face plate 21 is in the vicinity of a top of a truss at an end part of the hollow shape. An end part of the other face plate 22b is projected from the end part of the face plate 21. The face plate 22b is friction-agitation joined from an upper part. Then, a connection member 30 is arranged between the face plates 21, and friction-agitation joined from an upper part. The load in the friction- agitation joining is sustained by the ribs 23A, 23B. The whole structure is of the truss-structure which is light in weight and high in rigidity. |
