DAMPING ARRANGEMENT FOR A CABLE

Abstract

The invention relates to a damping arrangement (100) for a cable (102) extending in a tensioned manner from an anchorage (108), said damping arrangement (100) comprising a rigid damping action transfer device (112) which is positively connected to the cable (102) at a predetermined distance (L1) from said anchorage (108), and at least one damping device (110) extending in a damping manner between said damping action transfer device (112) and a constructional element (106) rigidly connected to said anchorage (108), and connected to said damping action transfer device (112) at a further predetermined distance (L2) from said anchorage (108), said further predetermined distance (L2) being shorter than said predetermined distance (L1).

Claims

1. Damping arrangement for a cable extending in a tensioned manner from an anchorage, said damping arrangement comprising a rigid damping action transfer device which is positively connected to the cable at a predetermined distance from said anchorage, and at least one damping device extending in a damping manner between said damping action transfer device and a constructional element rigidly connected to said anchorage, and connected to said damping action transfer device at a further predetermined distance from said anchorage, said further predetermined distance being shorter than said predetermined distance.

2. Damping arrangement according to claim 1, wherein said rigid damping action transfer device is formed by a rigid transition pipe surrounding the cable adjacent to the anchorage.

3. Damping arrangement according to claim 1, wherein a force transmitting device is located between the cable and the damping action transfer device for positively connecting the cable to the damping action transfer device.

4. Damping arrangement according to claim 3, wherein the force transmitting device includes a resilient element adapted and configured to be compressed between two compression plates so as to be expanded in a direction orthogonal to the plate planes of the compression plates.

5. Damping arrangement according to claim 3, wherein said resilient element has an annular shape and/or is arranged to surround the cable.

6. Damping arrangement according to claim 3, wherein the force transmitting device engages a compacting clamp unit adapted and intended for compacting a plurality of wires and/or strands of said cable to a side-by-side arrangement.

7. Damping arrangement according to claim 1, wherein the damping action transfer device is pivotably supported at its anchorage end.

8. Damping arrangement according to claim 7, wherein said rigid damping action transfer device is formed by a rigid transition pipe surrounding the cable adjacent to the anchorage, and wherein a resilient ring is arranged between the axial end surface of the anchorage end of the transition pipe and a corresponding support surface of the anchorage.

9. Damping arrangement according to claim 7, wherein said rigid damping action transfer device is formed by a rigid transition pipe surrounding the cable adjacent to the anchorage, and wherein the anchorage end of the transition pipe is in sliding contact with at least one socket element allowing a pivoting movement of the transition pipe around its anchorage end.

10. Damping arrangement according to claim 9, wherein the at least one socket element has a convex surface pointing towards the outer surface of the transition pipe.

11. Damping arrangement according to claim 1, wherein an angle formed between the at least one damping device and the cable amounts to less than 90°.

12. Damping arrangement according to claim 1, wherein a plurality of damping devices is connected to the rigid damping action transfer device.

13. Damping arrangement according to claim 12, wherein at least two damping devices are connected at different further predetermined distances to the rigid damping action transfer device.

14. Damping arrangement according to claim 12, wherein at least two damping devices, when seen along the cable's longitudinal direction, are crossing each other between their respective two ends.

15. Damping arrangement according to claim 1, wherein at least one damping device is formed as one of a passive fluidic damper, a semi-active fluidic damper, a friction damper and an elastomer damper.

16. Damping arrangement according to claim 2, wherein a force transmitting device is located between the cable and the damping action transfer device for positively connecting the cable to the damping action transfer device.

17. Damping arrangement according to claim 4, wherein said resilient element has an annular shape and/or is arranged to surround the cable.

18. Damping arrangement according to claim 8, wherein said rigid damping action transfer device is formed by a rigid transition pipe surrounding the cable adjacent to the anchorage, and wherein the anchorage end of the transition pipe is in sliding contact with at least one socket element allowing a pivoting movement of the transition pipe around its anchorage end.

Description

[0023] In the following, the present invention will be explained in more detail referring to specific embodiments shown in the attached drawing, in which

[0024] FIG. 1 shows a partially sectional view of a stay cable equipped with a first embodiment of a damping arrangement according to the present invention;

[0025] FIG. 2 shows an enlarged view of detail II in FIG. 1;

[0026] FIG. 3 shows an enlarged view of detail Ill in FIG. 1;

[0027] FIG. 4 shows a partially sectional view taken according to line IV-IV in FIG. 1 of a damping arrangement having one damping device;

[0028] FIG. 5 shows a view similar to FIG. 4 of a damping arrangement having two damping devices, i.e. of a second embodiment of a damping arrangement;

[0029] FIG. 6 shows a partially sectional view similar to FIG. 1 of a stay cable equipped with a third embodiment of a damping arrangement according to the present invention; and

[0030] FIG. 7 shows a partially sectional view according to line VII-VII in FIG. 6 of the embodiment of FIG. 6.

[0031] FIG. 1 shows a damping arrangement 100 which is applied to a stay cable 102 of a cable-stayed bridge 104 which is schematically represented by its driving and/or walking deck 106 and the anchorage 108 for the stay cable 102. The stay cable 102 extends in a tensioned manner from the anchorage 108 to a corresponding anchorage (not shown) of a pylon (not shown) of the cable-stayed bridge 104 so as to contribute to supporting the driving deck 106.

[0032] The damping arrangement 100 comprises a damping device 110 and a rigid transition pipe 112 surrounding the cable 102.

[0033] At a predetermined distance L1 from the anchorage 108, the rigid transition pipe 112 is positively connected to the outer surface of the cable 102, or to the outer surface of a compacting clamp 114 compacting a plurality of wires and/or strands 116 of the cable 102 to a side-by-side arrangement, to be precise, via a force transmitting device 118.

[0034] As may be seen in more detail from FIG. 2, the force transmitting device 118 may include a resilient element 120 which is compressed between two compression plates 122, 124 so as to be expanded in a direction orthogonal to the plate planes of the compression plates 122, 124. In this way, the radially inner expanded portion of the resilient element 120 may positively abut against the cable 102 or the compacting clamp 114 connected thereto, while the radially outer expanded portion of the resilient element 120 may positively abut against the inner surface of the transition pipe 112. The resilient element 120 may, for example, have an annular shape and may be arranged to surround the cable 102.

[0035] In this way, any vibrational movement of the cable 102 is transmitted to the transition pipe 112.

[0036] In order to allow the transition pipe 112 to freely follow vibrational movements of the cable 102, it is pivotably supported at its anchorage end 112a. For this purpose, as may be seen from FIG. 3, the axial end surface 112b of the transition pipe 112 is supported by a resilient ring 126 arranged between the axial end surface 112b of the transition pipe 112 and a corresponding support surface 108a of the anchorage 108. Furthermore, an outer surface 112c of the transition pipe 112 is slidingly guided in a socket ring 128 having a convex surface 128a slidingly abutting against the outer surface 112c of the transition pipe 112.

[0037] Due to the afore-described design, any vibrational movement of the cable 102 is transferred to a pivoting movement of the transition pipe 112 around its anchorage end 112a.

[0038] In order to dampen the vibrational movement of the cable 102, i.e. the pivoting movement of the transition pipe 112, the damping device 110 is connected to the transition pipe 112 at a second predetermined distance L2 from the anchorage 108, which is shorter than the first predetermined distance L1. As a consequence, the effective connection point, which is relevant for the technical design of the damping arrangement 100, may be located far away from the anchorage 108, namely at the first predetermined distance L1, while the damping device 110 needs not to be directly attached to the cable 102, but may be attached to the transition pipe 112 at a position closer to the anchorage 108, namely at the second predetermined distance L2. As may be easily understood, due to its rigidity, the transition pipe 112 thus fulfills the function of a damping action transfer device.

[0039] As may be seen from FIG. 1, the damping device 110, on the one side, and the cable 102 or the transition pipe 112, respectively, on the other side, form an angle α between them, which amounts to less than 90°. In this way, the damping device 110 can be arranged steeper than with conventional damper arrangements and thus be shorter.

[0040] As far as the damping device is concerned, several alternative embodiments are conceivable.

[0041] According to a first alternative embodiment shown in FIG. 4, one single damping device 110 may extend between the driving deck 106 and the transition pipe 112.

[0042] According to a second alternative shown in FIG. 5, two damping devices 110-1, 110-2 may extend between the driving deck 106 and the transition pipe 112. The two damping devices 110-1, 110-2 may form an angle β between them, which is different from 0°. In this way lateral movements of the transition pipe 112 indicated by arrows L may be dampened as well.

[0043] While the two damping devices 110-1, 110-2 are attached to the transition pipe 112 at the same predetermined distance L2 from the anchorage, this needs not necessarily to be the case, as is shown by the third alternative of FIGS. 6 and 7 for the damping devices 110-3, 110-4. While damping device 110-3 is attached to the transition pipe 112 at a predetermined distance L2a from the anchorage 108, damping device 110-4 is attached to the transition pipe 112 at a predetermined distance L2b from the anchorage 108, still being shorter than the first predetermined distance L1.

[0044] The different distances L2a and L2b provide for a further flexibility in the design of the damping arrangement 100. For example, the two damping devices 110-3 and 110-4, when seen along the cable's longitudinal direction A, may be crossing each other between their respective two ends, i.e. extend in analogy to skew lines. This configuration allows an even more effective dampening of lateral vibrations of the cable 102.

[0045] Finally, it is to be emphasized that the invention isn't restricted to a specific type of damper. Rather, at least one damping device may be constituted by a passive fluidic damper or a semi-active fluidic damper or a friction damper or an elastomer damper.