| 摘要 |
<p>A method of manufacturing a stepped riser e.g. for use in sports stadia and the like comprises providing a first sheet of metal 10 with a layer of plastics or polymer material 50 bonded to the metal 10 with at least one indentation 46, 48 formed in the layer of plastics or polymer material 50. The indentation 46, 48 in the plastics or polymer layer allows bending of the sheet of metal 10 along a pre-determined line without inducing compression or tension forces through the thickness of the layer of plastics or polymer material 50. A later embodiment relates to an element for forming into a stepped riser and a separate embodiment to a member for changing the mechanical dynamic performance of a stepped riser.</p> |
