MAURER SOHNE

Vibration of Stay Cables Rain in combination with wind can cause considerable vibrations in stay cables. In unfavourable circumstances, the magnitude of the vibrations of the stay cables can endanger the total bridge structure, in particular when the vibrations match the natural frequency of the bridge structure. But as a minimum, undesired vibrations may lead to fatigue problems, reducing the design life of stay cables, and also shortening the maintenance interval. 40 30 Modes of vibrations of stay cables, and their natural frequencies Hysteresis of a viscous damper (above) andan elastomeric...

Example of an externally arranged viscous cable damper (Eiland Bridge, Kampen, NL). What kinds of cable dampers are available ? All cable dampers have in common that they are attached to the stay cable close to their end, at the level of the bridge deck. At that location they will enact some force onto the vibrating cable, thus reducing the amplitude of the vibration. Cable dampers can be arranged internally, that is within the protection tube, or externally. Internal cable dampers are usually cheaper than the external ones, and will not affect the aesthetics of the bridge, and they may offer...

Hysteresis of an adaptive magnetorheological damper at different currents Adaptive Cable Dampers (ACDs) As its name implies, an adaptive linear viscous damper can adapt its response force to the modal shapes of the vibrating cable, thus making sure that always optimum damping is enacted. . The damper thus adapts to the existing situation on site, taking into account the specific parameters that make the cables vibrate, and tunes itself optimally to the situation by way of a certain algorithm Maurer Magneto-Rheological Dampers (MRDs) can be considered to be a member of the family of adaptive cable...

no MR damper, free cable signal of accelerometer @ 24% cable length after double integration signal of accelerometer @ 24% cable length after double integration Decay of vibrations of an undamped cable, i.e. no cable damper attached Decay Curves The effect of an adaptive magnetorheological cable damper can be seen from the 3 figures above, which were taken from measurements at the Ijssel Bridge near Kampen, NL that were conducted by EMPA in Switzerland. The figures depict the decay of the amplitudes of a stay cable over the time, after the stay cable was excited by means of a rope in its natural...

Reference Projects Bridge Dubrovnik / Croatia Response Force variable from 1 – 40 kN Stroke ± 80 mm Supply of 20 adaptive cable dampers (ACDs) Eilandbrug Kampen / Netherlands Test installation of MAURER Adaptive Cable Damper: Response Force variable from 1 – 40 kN, Stroke ± 60 mm Length of damped cable = 163 m. Sutong Bridge / China MAURER ACD, Response Force variable from 1 – 50 kN, Stroke ± 65 mm Supply of a total of 200 cable dampers, both of type ACD and passive linear viscous dampers. Longest cable to be damped is 588 m. Maurer Söhne Head Office Frankfurter Ring 193, D-80807 München P.O....