摘要 |
<p>A structural metal sheet employed as an outer sheet for a railway vehicle, for example, is generally pretensioned in order to prevent buckling. Hitherto, the pretensioning is effected by various methods after or during the assembly of a structure. According to the invention, the metal sheet itself is pretensioned by a plastic working for increasing the flexural rigidity thereof. Thus, there is no bear of buckling, and the appearance is improved as compared with the prior art.</p> |