Xu P.-Z.,Tsinghua University |
Xu P.-Z.,Qingdao Technological University |
Yin X.-J.,GERB Qingdao Vibration Control Co. |
Gao X.-L.,GERB Qingdao Vibration Control Co. |
And 2 more authors.
Gongcheng Lixue/Engineering Mechanics | Year: 2012
This paper presents theoretical and experimental research work on the vertical vibration comfort and vibration control of passenger boarding bridge in Shanghai Pudong international airport phase II project. The FEM model of the passenger boarding bridge was built. The vibration characteristics and vibration responses under pedestrian excitation of the bridge were calculated. Through numerical simulation, the suitable parameters of tuned mass damper (TMD) were obtained. Measurement results indicate that the vibration of the boarding bridge can be significantly reduced by employing TMD.
Meinhardt C.,GERB Schwingungsisolierungen GmbH and Co. KG |
Yin X.,GERB Qingdao Vibration Control Co. |
Luo Y.,GERB Qingdao Vibration Control Co. |
Gao X.,GERB Qingdao Vibration Control Co.
Bridge Maintenance, Safety, Management and Life Extension - Proceedings of the 7th International Conference of Bridge Maintenance, Safety and Management, IABMAS 2014 | Year: 2014
This paper presents a practical project example for the successful application of 32 Tuned Mass Dampers (TMDs) to the Chong Qi Bridge in China (total length 7km - main bridge span 944 m) to reduce vortex shedding induced oscillations of the bridge's girder sections (section span 184 m). The application of such devices is a beneficial alternative to aerodynamic and aeroelastic optimization of the bridge deck by increasing structural damping to reduce the vertical dynamic response for the case that vortices shed off with a frequency that corresponds with the fundamental vertical bending frequency of the bridge. While aerodynamic measures only shift the critical wind speed for which these resonance effects occur, passive TMDs reduce the bridge's dynamic response. In detail, this contribution describes the TMD concept and the realized optimization of the Tuned Mass Damper units to achieve an optimum reduction effect whilst reducing the mass additional mass that has to be applied to the bridge. Results of preliminary work shop tests will be presented as well as the experimental dynamic analysis of several bridge segments that has been performed during the commissioning of the TMD. This analysis included the determination of the bridges relevant vibration modes and the corresponding structural damping from ambient vibration tests using several system identification techniques such as FDD, SSI and Rand Decrement Method algorithms. Especially the damping values of the bridge are within the scope of interest to verify the optimum performance of the applied TMD systems. In addition the interaction between bridge and TMD has been monitored also under ambient wind loading. Therefore an approach to additionally assess the effectiveness of the systems will also be introduced. © 2014 Taylor & Francis Group.
Nawrotzki P.,GERB Vibration Control Systems |
Wang W.,GERB Qingdao Vibration Control Co.
International Conference on Nuclear Engineering, Proceedings, ICONE | Year: 2013
Safety in nuclear facilities is of special importance and recent seismic events and the resulting damage in these facilities again bring up the discussion. One of the latest events is the 2007 Chuetsu earthquake in Japan. The arising damage in the Kashiwazaki Kariwa Nuclear Power Plant can be found in several reports like (Fukushima, 2007) and (Yamashita, 2008). Base-Control Systems (BCS) consist of Springdamper combinations with specifically designed stiffness and damping properties which can be described in the vertical and both horizontal directions. Nowadays these 3 dimensional supports are frequently used to reduce seismic acceleration levels of machine components, equipment and buildings as safety or non-safety related structures. They may also be applied to protect sensitive equipment or machinery against other catastrophic events, i.e. airplane impact which is of particular importance in nuclear facilities. By presenting specific executed examples, this article shall also underline the efficiency of the BCS which, in contrary to purely horizontally efficient Base-isolation Systems with rubber (BIS), is not extensively discussed in literature. Decisive characteristics of the shown applications are provided and the benefits of using this technology for machine or equipment manufacturers, designers or owners are explained. Copyright © 2013 by ASME.
Yin X.,GERB Qingdao Vibration Control Co. |
Wang J.,GERB Qingdao Vibration Control Co. |
Gao X.,GERB Qingdao Vibration Control Co. |
Zhang B.,GERB Qingdao Vibration Control Co. |
And 2 more authors.
Advances in Environmental Vibration - Proceedings of the 5th International Symposium on Environmental Vibration, ISEV 2011 | Year: 2011
In some modem High Speed Railway stations the track bed is coupled with the station structure, so the structure-born noise in the station can be a problem. For example in the High-Speed Railway ChônAn Station in Korea, high speed trains run on the fourth floor and the three lower floors are used for offices and service. The intended usage of the three lower floors requires that the control of vibration and noise were an inherent requirement from the beginning of the design phase. Without the noise reduction measure the acoustic pressure level of 85 dB (A) inside the ChônAn station was expected. This paper provides an adequate noise and vibration solution with steel spring floating slab track. It can be concluded through the theoretical and experimental research, with this technology the noise in the ChônAn Station is reduced by 25 to 30 dB(A) without considering ballast mat and acoustic shield. This application is successfully adapted without scarifying stability criteria including excessive deformation, displacement, and vertical acceleration.
Liu L.,Beijing Jiaotong University |
Liu C.,Beijing Jiaotong University |
Yin X.,Gerb Qingdao Vibration Control Co.
Applied Mechanics and Materials | Year: 2012
This paper presents experimental and finite element analysis result of a full-size Buckling Restrained Brace (BRB). The brace consists of a steel core encased in a steel tube filled with concrete. The low-cycle fatigue check was incorporated into the cyclic test program. Test results show that the BRB product can develop stable hysteretic responses up to core axial strain of 1.3% and the maximum compressive loads is 1.23 times the actual yield load. The specimen performs well through the whole test sequence. Nonlinear finite element analysis was conducted for a comparison analysis, and contact interactions between the steel core and concrete infill were modeled. The finite element model can reasonably predict the compression behavior and post-yield strength of the specimen. © (2012) Trans Tech Publications.
Wang J.L.,GERB Qingdao Vibration Control Co. |
Chen G.F.,GERB Qingdao Vibration Control Co. |
Wang J.,GERB Qingdao Vibration Control Co.
Recent Advances in Environmental Vibration - Proceedings of 6th International Symposium on Environmental Vibration, ISEV 2013 | Year: 2013
Steel spring floating slab track (FST) has been widely used in urban rail transit lines since it was imported into China. In order to improve the speed and quality of FST and to match challenges of vibration control during construction period and challenges of transformation of running lines, the prefabricated floating slab track has been invented. Innovation has been achieved in structure design, system design and construction technology. Its safety and effectiveness have been verified by mechanical simulation with a integrated model, static load and fatigue test of system and elements. Test section is constructed in formal line and on-site measurement is accomplished at the section. Related researches won the first and second prize of Science and Technology Progress Awards respectively from Shanghai and Chinese government. Prefabricated floating slab track has been applied in Shanghai Metro for more than 30 kms, and will provide higher-level resolutions for noise and vibration control of running lines. It has become the most efficient and advanced one of the FST.
Sun Q.,Shanghai Power Equipment Research Institute |
Yin X.,Gerb Qingdao Vibration Control Co. |
Li W.,Shanghai Power Equipment Research Institute |
Wang X.,Shanghai Power Equipment Research Institute |
And 2 more authors.
Dongli Gongcheng Xuebao/Journal of Chinese Society of Power Engineering | Year: 2013
To quantitatively study the influence of foundation on dynamic characteristics of the shafting in turbine-generator set, numerical calculations were carried out to the support dynamic stiffness of different bearing seats for a 1000 MW nuclear power half-speed unit, under conditions respectively with conventional foundation and spring foundation, by taking the foundation and bearing seat as the boundary of support dynamic stiffness, based on which an analysis was performed to the main dynamic characteristics, such as the critical speed of shafting, the unbalance response of journal and the logarithm decrement of shafting, etc. Results show that the critical speed of rotors and the unbalance response of journals are very close in value under above two foundation conditions, with both instability speeds of shafting greater than 2000 r/min. The critical speed of rotor in horizontal mode declines and that in vertical mode rises, in the case spring foundation is adopted, under which condition the support stiffness can be optimized to a degree equivalent to conventional foundations via appropriate designs.