摘要
为解决常规非线性能量阱(nonlinear energy sink, NES)在低能量输入时难以触发靶向能量传递的问题,在立方刚度NES的基础上引入低阶非线性刚度项,提出一种组合刚度NES,以提高NES减震性能的鲁棒性。提出考虑不同层级能量输入的NES参数优化策略,采用遗传算法对组合刚度NES、立方刚度NES和调谐质量阻尼器(tuned mass damper, TMD)进行参数数值寻优,对比分析了不同阻尼器的减震性能。结果表明,组合刚度NES的减震性能全面优于立方刚度NES,对不同层级能量输入的鲁棒性几乎与TMD相当,而对主结构频率变化的鲁棒性则优于TMD。利用数值小波变换对地震响应的功率谱进行分析,揭示了组合刚度NES能在较宽频带与主结构产生强烈的瞬时内共振俘获行为,由此表明其具有极强的频率鲁棒性。对能量在受控系统中不同部分间的传递分析表明,高阶非线性刚度仅在高能量输入时转移主结构能量,而低阶非线性刚度在低能量输入时仍可有效转移主结构能量,揭示了组合刚度NES具有良好的能量输入鲁棒性。
Here,to solve the problem of conventional nonlinear energy sink(NES)during low energy input being difficult to trigger targeted energy transfer,a low order nonlinear stiffness term was introduced on the basis of cubic stiffness NES,and a combined stiffness NES was proposed to improve the robustness of NES seismic mitigation performance.A parametric optimization strategy for NES considering different levels of energy input was proposed,and genetic algorithm was used to numerically optimize parameters of combined stiffness NES,cubic stiffness NES and tuned mass damper(TMD).Seismic mitigation performances of different shock absorbers were analyzed contrastively.The results showed that seismic mitigation performance of combined stiffness NES is fully superior to that of cubic stiffness NES,and its robustness to energy input at different levels is almost equivalent to TMD’s,while its robustness to frequency changes of main structure is superior to TMD’s.Numerical wavelet transform was used to analyze power spectra of seismic responses,it was revealed that combined stiffness NES can generate strong instantaneous internal resonance capture behavior with main structure in a wider frequency band,so combined stiffness NES has extremely strong frequency robustness.The analysis of energy transfer among different parts of controlled system showed that high-order nonlinear stiffness can transfer main structure energy only during high energy input,while low order nonlinear stiffness can effectively transfer main structure energy even during low energy input,so combined stiffness NES has good energy input robustness.
作者
吴梦南
宁西占
张洪福
WU Mengnan;NING Xizhan;ZHANG Hongfu(College of Civil Engineering,Huaqiao University,Xiamen 361021,China;Key Laboratory for Intelligent Infrastructure and Monitoring of Fujian Province,Huaqiao University,Xiamen 361021,China;College of Civil Engineering and Architecture,Hainan University,Haikou 570228,China)
出处
《振动与冲击》
北大核心
2025年第9期203-213,共11页
Journal of Vibration and Shock
基金
国家自然科学基金(52478175
51908231)
福建省自然科学基金(2024J01075)
中央高校基本科研业务费专项资金项目(ZQN-912)。
关键词
非线性能量阱
组合刚度
减震性能
鲁棒性
nonlinear energy sink(NES)
combined stiffness
seismic mitigation performance
robustness
