München, Germany
München, Germany

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Friedrich H.,Bundesanstalt fur Strassenwesen | Empelmann M.,TU Braunschweig | Hamm S.,Hochtief Group | Freundt U.,Industriestrasse 1a | And 4 more authors.
Beton- und Stahlbetonbau | Year: 2013

The Federal Ministry of Transport, Building and Urban Development (BMVBS) together with the Federal Highway Research Institute (BASt) created a long-term framework research program called "Road in the 21st Century". The design of futurecompliant roads requires an integral approach also including bridges and structural technology. The following article deals with three completed and two current research projects with the focus on Innovations in Bridge Construction. © 2013 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.


Weber F.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Distl H.,Maurer Sohne GmbH and Co. KG
Beton- und Stahlbetonbau | Year: 2014

Stay cables are prone to wind-induced vibrations due to their low inherent damping of 0,1%-0,15%. Since wind conditions vary over time, vibration amplitudes and frequencies are unknown. Consequently, cable damping systems must generate amplitude and frequency independent cable damping. It is described how this requirement can be fulfilled by real-time controlled magnetorheological dampers. The efficiency of the adaptive cable damping system is experimentally validated and its implementation on the world largest stay cable bridges, the Sutong Bridge in China and the Russky Bridge in Russia, is described. Copyright © 2014 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.


Weber F.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Distl H.,Maurer Sohne GmbH and Co. KG
Scientific World Journal | Year: 2015

This paper discusses the damping measurements on cables with real-time controlled MR dampers that were performed on a laboratory scale single strand cable and on cables of the Sutong Bridge, China. The control approach aims at producing amplitude and frequency independent cable damping which is confirmed by the tests. The experimentally obtained cable damping in comparison to the theoretical value due to optimal linear viscous damping reveals that support conditions of the cable anchors, force tracking errors in the actual MR damper force, energy spillover to higher modes, and excitation and sensor cables hanging on the stay cable must be taken into consideration for the interpretation of the identified cable damping values. © 2015 Felix Weber and Hans Distl.


De Canio G.,ENEA | Mongelli M.,ENEA | Roselli I.,ENEA | Giocoli A.,ENEA | And 7 more authors.
SHMII 2015 - 7th International Conference on Structural Health Monitoring of Intelligent Infrastructure | Year: 2015

This paper describes the shaking table testing performed on the full-scale prototype of a device developed in the framework of the EC Collaborative Project SILER (Seismic-Initiated events risk mitigation in Lead-cooled Reactors) to protect the seismic gap in Generation IV LFRs (Lead-cooled Fast Reactors) provided with base isolation. The need of a seismic gap is due to the relative movement between the seismically isolated building and the adjacent ones, during earthquakes. In fact, collisions between the reactor building and the pit wall during beyond design seismic events can be avoided only by the presence of sufficient clearance between the two structures. The joint cover shall be waterproof, fireproof and resistant to impacts. The specimen was a 2.5 x 3.45 m full-scale prototype subjected to three seismic tests, sine and combined sine-sweep tests at the UTTMAT-QUAL laboratory of the ENEA Casaccia Research Center. Together with traditional accelerometers, a 3D motion capture system was used to measure triaxial absolute displacements with easy and fast test set-up, high accuracy and the possibility to link the 3D motion time histories with CAD drawings of the structure and validate the FE models in real time experimental data assimilation. © 2015, International Society for Structural Health Monitoring of Intelligent Infrastructure, ISHMII. All rights reserved.


Weber F.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Distl H.,Maurer Sohne GmbH and Co. KG
Beton- und Stahlbetonbau | Year: 2013

In May 2010, the Wolgograd Bridge underwent wind-induced bending vibrations with estimated amplitudes of up to 40 cm. Since November 2011, the Wolgograd Bridge is mitigated by adaptive tuned mass dampers whose frequency and damping are adjusted to the actual frequency of vibration in real-time by controlled MR dampers. This concept mitigates the bridge in the worst case similarly to and in all other cases better than passive tuned mass dampers. This improvement is achieved by approximately half the mass damper mass compared to passive tuned mass dampers which is a desirable feature for the bridge construction type. Copyright © 2013 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.


Weber F.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Distl H.,Maurer Sohne GmbH and Co. KG
Structural Control and Health Monitoring | Year: 2015

Two control approaches for magnetorheological (MR) dampers on cables based on collocated control without state estimation are formulated, which generate amplitude and frequency independent cable damping: cycle energy control and controlled viscous damping (CVD). The force tracking is solved by the inverted Bingham model whose parameters are fitted as function of current and frequency. Cycle energy control and CVD are experimentally validated by hybrid simulations and free decay tests on stay cables of the Sutong Bridge, China, and the Eiland Bridge, the Netherlands. The implementation of CVD on the Russky Bridge, Russia, includes two novelties: the force tracking also takes the actual MR damper temperature into account to ensure precise force tracking for MR damper temperatures -40 to +60 ° C and the decentralised real-time control units with pulse width current modulation are installed next to each MR damper to avoid long direct current (DC) power lines with associated losses and thereby minimise power consumption. © 2014 John Wiley & Sons, Ltd.


Weber F.,Empa - Swiss Federal Laboratories for Materials Science and Technology | Distl J.,Maurer Sohne GmbH and Co. KG | Maslanka M.,AGH University of Science and Technology
Conference Proceedings of the Society for Experimental Mechanics Series | Year: 2013

The Volgograd Bridge in Russia is known not only for its record length but also for the large amplitude vibrations induced by wind in May 2010. This paper describes the development of a new semi-active TMD with a magnetorheological damper (MR-STMD) that was installed on the Volgograd Bridge in fall 2011. The main feature of the MR-STMD concept is that the real-time controlled MR damper emulates a controllable stiffness force and a controllable friction force. The controllable stiffness force augments or diminishes the stiffness of the passive springs and thereby tunes the MR-STMD frequency to the actual frequency of the bridge. The controllable friction force generates frequency dependent energy dissipation. The small-scale prototype was experimentally tested on the 19.2 m long Empa bridge for various modal masses and disturbing frequencies. After that, the full-scale MR dampers were tested at Empa by hybrid testing for the expected frequencies and amplitudes of the bridge. Finally, the frequency controllability of one full-scale MR-STMD was verified at the University of the German Armed Forces, Munich. All tests confirm that the new technology can compensate for the frequency sensitivity of passive TMDs and works at high efficiency. © The Society for Experimental Mechanics, Inc. 2013.


Braun C.,Maurer Sohne GmbH and Co. KG | Butz C.,Maurer Sohne GmbH and Co. KG
Large Structures and Infrastructures for Environmentally Constrained and Urbanised Areas | Year: 2010

A seismic isolator shall be capable to transmit vertical loads, to decouple the prevailing mass from ground motions, to provide sufficient restoring force, energy dissipation and adequate functionality under service loads and movements. In case of curved surface sliders the friction between the main sliding surfaces is crucial for most of the fundamental requirements listed above. The quasi static coefficient of friction is the significant parameter for the determination of restoring forces due to movements under service conditions. The dynamic coefficient of friction is decisive for energy dissipation and restoring capability during a seismic event. Both these coefficients have to be determined in separate test procedures given in standards EN 1337-2 and EN 15129. This paper gives an overview of the state of the art comparing the European and American design rules.


Fobo W.,Maurer Sohne GmbH and Co. KG
40th International Congress and Exposition on Noise Control Engineering 2011, INTER-NOISE 2011 | Year: 2011

Nowadays noise emission poses an ever-increasing problem for designers of roads and bridges. In case of bridges noise emission is not only directed to above the carriageway, but also in direction below, and in addition is also being intensified due to oscillations of the bridge structure. Particularly cumbersome are noise emissions due to impacts like they usually occur at a non-smooth carriageway and at the expansion joints. MAURER has realized the importance of noise reduction of expansion joints already about 20 years ago. Since 1991, Maurer investigates in noise reduction of expansion joints by means of test vehicles passing expansion joints of different design types. Copyright © (2011) by the Institute of Noise Control Engineering.

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