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
针对海上单桩风机支撑结构在风浪荷载作用下的动力响应与减振设计开展研究。首先,建立某6.45 MW海上风电机组单桩集中质量-梁杆模型,利用Kaimal谱计算风荷载、Jonswap谱模拟波浪荷载,分析单桩风机结构的动力振动特性。随后,基于多重调...针对海上单桩风机支撑结构在风浪荷载作用下的动力响应与减振设计开展研究。首先,建立某6.45 MW海上风电机组单桩集中质量-梁杆模型,利用Kaimal谱计算风荷载、Jonswap谱模拟波浪荷载,分析单桩风机结构的动力振动特性。随后,基于多重调谐质量阻尼器(Muti-Tuned Mass Damper,MTMD),设计1阶、2阶TMD,以结构振动响应为目标,研究该减振方案的适用性。研究表明,支撑结构的加速度、位移响应受塔架基频影响较大,且加速度受2阶基频主控,位移受1阶基频主控。当外荷载较大时,MTMD的减振效果会有所提高。MTMD体系的减振效果明显,各响应的减小率达到50%,且塔架的1阶、2阶频谱主峰值明显降低。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
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.
文摘针对海上单桩风机支撑结构在风浪荷载作用下的动力响应与减振设计开展研究。首先,建立某6.45 MW海上风电机组单桩集中质量-梁杆模型,利用Kaimal谱计算风荷载、Jonswap谱模拟波浪荷载,分析单桩风机结构的动力振动特性。随后,基于多重调谐质量阻尼器(Muti-Tuned Mass Damper,MTMD),设计1阶、2阶TMD,以结构振动响应为目标,研究该减振方案的适用性。研究表明,支撑结构的加速度、位移响应受塔架基频影响较大,且加速度受2阶基频主控,位移受1阶基频主控。当外荷载较大时,MTMD的减振效果会有所提高。MTMD体系的减振效果明显,各响应的减小率达到50%,且塔架的1阶、2阶频谱主峰值明显降低。
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.
