大型化工管道受管内流体流动、边界约束、振源激励等复杂因素影响,服役期间往往会发生振动,其振动频率相较于土木结构较高,且可能存在多个主要频率成分.若采用单一频率的调谐质量阻尼器(Tuned Mass Damper,TMD),难以达到理想的控制效果...大型化工管道受管内流体流动、边界约束、振源激励等复杂因素影响,服役期间往往会发生振动,其振动频率相较于土木结构较高,且可能存在多个主要频率成分.若采用单一频率的调谐质量阻尼器(Tuned Mass Damper,TMD),难以达到理想的控制效果,而采用多重调谐质量阻尼器(Multiple Tuned Mass Damper,MTMD)时,受现场条件限制,又存在无法确定最优安装位置等问题.本文开展了基于MTMD的管道倍频响应减振研究.首先,开展了某化工企业丙烷脱氢装置的大型管道现场实测研究,发现管道振动频率存在明显的倍数关系,即倍频现象.其次,建立局部管道有限元模型,分析管道动力特性,提出了基于数值搜索法的MTMD参数设计方法.最后,考虑化工管道现场安装条件的限制,研究了MTMD安装位置对管道减振效果的影响.数值研究结果表明,安装MTMD可有效减小管道振动响应.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
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
文摘大型化工管道受管内流体流动、边界约束、振源激励等复杂因素影响,服役期间往往会发生振动,其振动频率相较于土木结构较高,且可能存在多个主要频率成分.若采用单一频率的调谐质量阻尼器(Tuned Mass Damper,TMD),难以达到理想的控制效果,而采用多重调谐质量阻尼器(Multiple Tuned Mass Damper,MTMD)时,受现场条件限制,又存在无法确定最优安装位置等问题.本文开展了基于MTMD的管道倍频响应减振研究.首先,开展了某化工企业丙烷脱氢装置的大型管道现场实测研究,发现管道振动频率存在明显的倍数关系,即倍频现象.其次,建立局部管道有限元模型,分析管道动力特性,提出了基于数值搜索法的MTMD参数设计方法.最后,考虑化工管道现场安装条件的限制,研究了MTMD安装位置对管道减振效果的影响.数值研究结果表明,安装MTMD可有效减小管道振动响应.
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。
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.
