| 摘要 |
<p>Provided is a plate-shaped material (1) which has a recessed and projected portion (20) formed to enhance rigidity. The recessed and projected portion is formed with reference to a first reference plane (K1), an intermediate reference plane (K3), and a second reference plane (K2). It is assumed that the intermediate reference plane (K3) is defined by a first grid straight line (L1), a second grid straight line (L2), and a third grid straight line (L3), and filled with a hexagonal unit region (24) and a triangular unit region (25). Those regions made up of the hexagonal unit region (24) and the triangular unit region (25) are to be a first reference region (214), a second reference region (224), and a third reference region (234), so that combinations thereof form a new first reference region (213), a new second reference region (223), and a new third reference region (233). The recessed and projected portion (20) is made up of a first region (21) and a second region (22) which include the new first reference region (213) and the new second reference region (223), and an intermediate plane (23) which includes the new third reference region (233).</p> |
