| 摘要 |
The invention relates to a tubular pole 1. The rigidity thereof is maintained by static interaction between at least two elements disposed at different radial centre distances and forming part of the pole. As a result of local stress in the transverse direction of the pole 1, the said static interaction is brought to an end. The result is that the pole collapses. According to the invention, the said elements are layers 4,5,6 in a laminate material which forms the wall of the tubular pole 1. The pole 1 has been given a local region A in which the said static interaction is weakened by a delamination tendency of the layers 4,5,6 which is enhanced relative to rest of the pole. When the pole 1 is subjected to transverse forces in the region A, it collapses here but remains otherwise intact. <IMAGE> |
