| 摘要 |
<p>Webs for reducing bending in board-shaped construction elements when in use have their main direction of load perpendicular to the board plane. The devices have a sandwich of at least one first material layer, one second material layer, and one third material layer. The third material layer lies between the other two material layers and has a substantially higher coefficient of heat expansion than the other two material layers, so as to set up contracting biasing forces in the third material layer. The third material is made of a sheet metal strip. The two other materials are made of thermosetting plastic, which sets at a temperature considerably above the working temperature of the construction element.</p> |
