摘要
当单摆式调谐质量阻尼器（PTMD）的频率调谐至与结构的自振频率一致时，PTMD有良好的减振效果。由于结构的设计频率与实际频率之间的偏差和结构在使用过程中发生的损伤累积等，结构的自振频率可能会偏离PTMD的控制频率，降低PTMD的减振效果。为了改善传统PTMD对频率调谐敏感的缺陷，提出的自适应单摆式TMD基于PTMD频率仅与摆长有关的特点，利用短时傅里叶变换和环境激励法识别出结构的自振频率，然后自发地启动步进电机改变摆长，以调节PTMD频率与结构频率相同。介绍了一种自适应单摆式TMD的模型装置，并用数值模拟对比了其在各种激励作用下的结构响应。结果表明，自适应单摆式TMD对结构的频率识别精度高，能够提高结构的等效阻尼比，降低结构的加速度响应。自适应单摆式TMD能够提高PTMD的减振效果，提高结构的安全性和耐久性，延长结构的使用寿命，且构造简单、需电量小，具有较好的工程应用前景。
When the natural frequency of pendulum-type tuned mass damper （PTMD） is consist- ent with that of the main structure, the vibration can be controlled effectively. Because the engi- neering structural design frequency may be different from the actual frequency, together with the accumulated damage during operation, the actual natural frequency of the main structure will de- viate from that of the PTMD, hence greatly reducing the effect of PTMD on controlling vibra- tion. In order to overcome the deficiency of traditional PTMDs, an adaptive PTMD device is pro- posed in this paper on the basis that the frequency of PTMD is only related to the pendulum length. Short-time fourier transform and natural excitation method are used to identify the natu- ral frequency of the main structure, and then, the step motor initiates spontaneously to change the pendulum length to adiust its frequency to match the main structural frequency. This paper proposes a test apparatus of adaptive PTMD, and simulates its structural responses under differ- ent excitations. The results show that the adaptive PTMD can precisely identify the structuralfrequency, and it can improve the structural equivalent damping ratio and reduce the structural acceleration response. Adaptive PTMD can improve the vibration control effect of PTMD, im- prove the safety and durability of a structure, and extend its service life. Moreover, it is simple and energy efficient. Therefore, adaptive PTMDs have a bright prospect in engineering applica- trans.
作者
王梁坤
施卫星
鲁正
WANG Liangkun;SHI Weixing;LU Zheng(Research Institute of Structural Engineering and Disaster Reduction,Tongji University,Shanghai 200092,China)
出处
《防灾减灾工程学报》
CSCD
北大核心
2018年第4期693-699,共7页
Journal of Disaster Prevention and Mitigation Engineering
基金
国家自然科学基金项目(51478361)资助
关键词
PTMD
短时傅里叶变换
频率识别
自适应单摆式TMD
数值模拟
pendulum-type tuned mass damper
short-time Fourier transform
frequency identifi-cation
adaptive pendulum-type tuned mass damper~ numerical simulation
