| 摘要 |
<p>Cold-rolled steel purlins have parallel opposite directed flanges, one major and one minor each with a flat outer fixing surface, terminal inturned lip and longitudinal strengthening groove nearer the inner edge where a central connecting web joins at 90.degree. but is so angled in central regions that a notional plane at right angles to each flange flat surface longitudinal midline passes through the web and the other flange flat surface. The minor flange outer contour matches the major flange inner contour. The flange lips are angled at least in part at less than 90.degree.. The purlin has good mechanical properties, and can be nested in pairs (with minor flanges inside major flanges) or stacked in the same sense either as individuals or as nested pairs (Figure 1).</p> |
