The issue of low-frequency structural noise radiated from high-speed railway(HSR) box-girder bridges(BGBs) is a significant challenge worldwide. Although it is known that vibrations in BGBs caused by moving trains can...The issue of low-frequency structural noise radiated from high-speed railway(HSR) box-girder bridges(BGBs) is a significant challenge worldwide. Although it is known that vibrations in BGBs caused by moving trains can be reduced by installing multiple tuned mass dampers(MTMDs) on the top plate, there is limited research on the noise reduction achieved by this method. This study aims to investigate the noise reduction mechanism of BGBs installed with MTMDs on the top plate. A sound radiation prediction model for the BGB installed with MTMDs is developed, based on the vehicle–track–bridge coupled dynamics and acoustics boundary element method. After being verified by field tested results, the prediction model is employed to study the reduction of vibration and noise of BGBs caused by the MTMDs. It is found that installing MTMDs on top plate can significantly affect the vibration distribution and sound radiation law of BGBs. However, its impact on the sound radiation caused by vibrations dominated by the global modes of BGBs is minimal. The noise reduction achieved by MTMDs is mainly through changing the acoustic radiation contributions of each plate of the bridge. In the lower frequency range, the noise reduction of BGB caused by MTMDs can be more effective if the installation of MTMDs can modify the vibration frequency and distribution of the BGB to avoid the influence of small vibrations and disperse the sound radiation from each plate.展开更多
This paper studies optimization of three design parameters （mass ratio, frequency ratio and damping ratio） of multiple tuned mass dampers MTMDs that are applied in a cable stayed bridge excited by a strong wind usin...This paper studies optimization of three design parameters （mass ratio, frequency ratio and damping ratio） of multiple tuned mass dampers MTMDs that are applied in a cable stayed bridge excited by a strong wind using minimax optimization technique. ABAQUS finite element program is utilized to run numerical simulations with the support of MATLAB codes and Fast Fourier Transform FFT technique. The optimum values of these three parameters are validated with two benchmarks from the literature, first with Wang and coauthors and then with Lin and coauthors. The validation procedure detected a good agreement between the results. Box-Behnken experimental method is dedicated to formulate the surrogate models to represent the control efficiency of the vertical and torsional vibrations. Sobol＇s sensitivity indices are calculated for the design parameters in addition to their interaction orders. The optimization results revealed better performance of the MTMDs in controlling the vertical and the torsional vibrations for higher mode shapes. Furthermore, the calculated rational effects of each design parameter facilitate to increase the control efficiency of the MTMDs in conjunction with the support of the surrogate models.展开更多
Multimodal control for seismic responses of tall buildings is performed by using MTMDs. Installation and main parameters of MTMDs are described, equations of motion of the coupled system of tall buildings and MTMDs ar...Multimodal control for seismic responses of tall buildings is performed by using MTMDs. Installation and main parameters of MTMDs are described, equations of motion of the coupled system of tall buildings and MTMDs are built under earthquake excitations, and parametrical optimization for multimodal control is carried out under excitations of harmonic ground motion. An 11 story frame building controlled by MTMDs is simulated under the excitation of El Centro earthquake (1940, NS), and its displacement response at the top floor in the case of multimodal control is reduced by 20% more than the case of single modal control. Some conclusions are given as the MTMDs is an effective, reliable and practical passive measurement for controlling seismic responses of tall buildings and the multimodal control has better adaptability and reliability by comparison with the single modal control.展开更多
为了探究钢混组合式塔架结构(混塔)在风载荷和地震波联合作用下的结构响应,建立了钢混组合式塔架的有限元模型,采用Davenport脉动风速谱,基于AR线性滤波法对脉动风速进行时程模拟;并基于结构所处的场地条件,对混塔进行相应的地震波时程...为了探究钢混组合式塔架结构(混塔)在风载荷和地震波联合作用下的结构响应,建立了钢混组合式塔架的有限元模型,采用Davenport脉动风速谱,基于AR线性滤波法对脉动风速进行时程模拟;并基于结构所处的场地条件,对混塔进行相应的地震波时程分析。在此基础上,采用基础隔震结构、单个调谐质量阻尼器(single tuned mass damper, STMD)和分布式多重调谐质量阻尼器(distributed multiple tuned mass damper, D-MTMDs)结构、以及隔震结构和D-MTMDs结构组合而成的混合控制结构等一系列控制方法对混塔的响应进行了控制,并采用了七种评价指标对各控制方法的优劣进行了相应的评估。计算结果表明,混合控制结构可以结合隔震结构和D-MTMDs结构的控制优点,不仅展现对风载响应的良好控制,也显示出对风载和地震波联合载荷响应优异的控制效果。展开更多
For the offshore wind turbines installed in earthquake areas,their operation is affected by seismic loads in addition to wind and wave loads.Therefore,it is necessary to study the dynamic responses and vibration contr...For the offshore wind turbines installed in earthquake areas,their operation is affected by seismic loads in addition to wind and wave loads.Therefore,it is necessary to study the dynamic responses and vibration control of the wind turbines.In previous studies,the structural responses of offshore wind turbines are usually investigated in the parked case,while the blade rotation effect is usually not considered.The evaluation on the structural responses may be inaccurate under this condition,further affecting the evaluation on the vibration control performance of a control system.In view of it,this paper established a complete multi-body model of a fixed-bottom offshore wind turbine considering pile-soil interaction,and then performed simulations when the wind turbine was subjected to multiple external excitations.Continued,a single tuned mass damper(STMD)system and a multiple tuned mass dampers(MTMDs)system were applied to control structural vibrations of the wind turbine.Then,based on the construction of a simplified main structure-TMD system,TMD parameters were optimized.Finally,twelve load cases including operating and parked conditions were selected to perform simulations.Results show that the influence of the seismic excitation on blade responses is greater under the parked condition than that under the operating condition.Moreover,STMD/MTMDS exhibit better performance under the parked condition than that under the operating condition.Compared with STMD,MTMDS can better suppress the vibrations at both the fundamental and high-order modes,and exhibits significant robustness under the condition of changing soil parameters.展开更多
基金supported by the National Natural Science Foundation of China (NSFC) (Grant Nos. 52362049 and 52208446)the Natural Science Foundation of Gansu Province (Grant Nos. 22JR5RA344 and 22JR11RA152)+4 种基金the Special Funds for Guiding Local Scientifi c and Technological Development by the Central Government (Grant No. 22ZY1QA005)the Joint Innovation Fund Project of Lanzhou Jiaotong University and Corresponding Supporting University (Grant No. LH2023016)the Fundamental Research Funds for the Central Universities (2682023ZTZ010), the Lanzhou Science and Technology planning Project (Grant No. 2022-ZD-131)the key Research and Development Project of Lanzhou Jiaotong University (Grant No. LZJTU-ZDYF2302)the University Youth Fund Project of Lanzhou Jiaotong University (Grant No. 2021014)。
文摘The issue of low-frequency structural noise radiated from high-speed railway(HSR) box-girder bridges(BGBs) is a significant challenge worldwide. Although it is known that vibrations in BGBs caused by moving trains can be reduced by installing multiple tuned mass dampers(MTMDs) on the top plate, there is limited research on the noise reduction achieved by this method. This study aims to investigate the noise reduction mechanism of BGBs installed with MTMDs on the top plate. A sound radiation prediction model for the BGB installed with MTMDs is developed, based on the vehicle–track–bridge coupled dynamics and acoustics boundary element method. After being verified by field tested results, the prediction model is employed to study the reduction of vibration and noise of BGBs caused by the MTMDs. It is found that installing MTMDs on top plate can significantly affect the vibration distribution and sound radiation law of BGBs. However, its impact on the sound radiation caused by vibrations dominated by the global modes of BGBs is minimal. The noise reduction achieved by MTMDs is mainly through changing the acoustic radiation contributions of each plate of the bridge. In the lower frequency range, the noise reduction of BGB caused by MTMDs can be more effective if the installation of MTMDs can modify the vibration frequency and distribution of the BGB to avoid the influence of small vibrations and disperse the sound radiation from each plate.
文摘This paper studies optimization of three design parameters （mass ratio, frequency ratio and damping ratio） of multiple tuned mass dampers MTMDs that are applied in a cable stayed bridge excited by a strong wind using minimax optimization technique. ABAQUS finite element program is utilized to run numerical simulations with the support of MATLAB codes and Fast Fourier Transform FFT technique. The optimum values of these three parameters are validated with two benchmarks from the literature, first with Wang and coauthors and then with Lin and coauthors. The validation procedure detected a good agreement between the results. Box-Behnken experimental method is dedicated to formulate the surrogate models to represent the control efficiency of the vertical and torsional vibrations. Sobol＇s sensitivity indices are calculated for the design parameters in addition to their interaction orders. The optimization results revealed better performance of the MTMDs in controlling the vertical and the torsional vibrations for higher mode shapes. Furthermore, the calculated rational effects of each design parameter facilitate to increase the control efficiency of the MTMDs in conjunction with the support of the surrogate models.
文摘Multimodal control for seismic responses of tall buildings is performed by using MTMDs. Installation and main parameters of MTMDs are described, equations of motion of the coupled system of tall buildings and MTMDs are built under earthquake excitations, and parametrical optimization for multimodal control is carried out under excitations of harmonic ground motion. An 11 story frame building controlled by MTMDs is simulated under the excitation of El Centro earthquake (1940, NS), and its displacement response at the top floor in the case of multimodal control is reduced by 20% more than the case of single modal control. Some conclusions are given as the MTMDs is an effective, reliable and practical passive measurement for controlling seismic responses of tall buildings and the multimodal control has better adaptability and reliability by comparison with the single modal control.
文摘为了探究钢混组合式塔架结构(混塔)在风载荷和地震波联合作用下的结构响应,建立了钢混组合式塔架的有限元模型,采用Davenport脉动风速谱,基于AR线性滤波法对脉动风速进行时程模拟;并基于结构所处的场地条件,对混塔进行相应的地震波时程分析。在此基础上,采用基础隔震结构、单个调谐质量阻尼器(single tuned mass damper, STMD)和分布式多重调谐质量阻尼器(distributed multiple tuned mass damper, D-MTMDs)结构、以及隔震结构和D-MTMDs结构组合而成的混合控制结构等一系列控制方法对混塔的响应进行了控制,并采用了七种评价指标对各控制方法的优劣进行了相应的评估。计算结果表明,混合控制结构可以结合隔震结构和D-MTMDs结构的控制优点,不仅展现对风载响应的良好控制,也显示出对风载和地震波联合载荷响应优异的控制效果。
基金Project supported by the Major State Basic Research Development Program of China(973 Program)(No.2015CB060000)the National Natural Science Foundation of China(Nos.51378111 and 51438002)+2 种基金the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China(No.142007)the Program for New Century Excellent Talents in University of Ministry of Education of China(No.NCET-13-0128)the Jiangsu Key Laboratory of Environmental Impact and Structural Safety in Engineering,China University of Mining & Technology(No.JSKL2014K03),China
基金sponsored by the Scientific Research Foundation of Chongqing University of Technology (Grant No. 2020ZDZ023)the Project of Science and Technology Research Program of Chongqing Education Commission of China (Grant No. KJQN202101133)+2 种基金the National Natural Science Foundation Cultivation Program of Chongqing University of Technology (Grant No.2021PYZ14)Shanghai Engineering Research Center of Marine Renewable Energy (Grant No. 19DZ2254800)the Science and Technology Research Program of Chongqing Municipal Education Commission (Grant No. KJQN201805801)
文摘For the offshore wind turbines installed in earthquake areas,their operation is affected by seismic loads in addition to wind and wave loads.Therefore,it is necessary to study the dynamic responses and vibration control of the wind turbines.In previous studies,the structural responses of offshore wind turbines are usually investigated in the parked case,while the blade rotation effect is usually not considered.The evaluation on the structural responses may be inaccurate under this condition,further affecting the evaluation on the vibration control performance of a control system.In view of it,this paper established a complete multi-body model of a fixed-bottom offshore wind turbine considering pile-soil interaction,and then performed simulations when the wind turbine was subjected to multiple external excitations.Continued,a single tuned mass damper(STMD)system and a multiple tuned mass dampers(MTMDs)system were applied to control structural vibrations of the wind turbine.Then,based on the construction of a simplified main structure-TMD system,TMD parameters were optimized.Finally,twelve load cases including operating and parked conditions were selected to perform simulations.Results show that the influence of the seismic excitation on blade responses is greater under the parked condition than that under the operating condition.Moreover,STMD/MTMDS exhibit better performance under the parked condition than that under the operating condition.Compared with STMD,MTMDS can better suppress the vibrations at both the fundamental and high-order modes,and exhibits significant robustness under the condition of changing soil parameters.
