Active isolation tests of metamaterial-based barriers and foundation
Active isolation tests of metamaterial-based barriers and foundation
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DOI：
10.1016/j.engstruct.2022.114253
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发表时间：
2022-06
影响因子：
5.5
通讯作者：
Jiaji Wang;Hsuan-Wen Huang;Benchen Zhang;F. Menq;K. Nakshatrala;Y. Mo;K. Stokoe
中科院分区：
文献类型：
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作者：
Jiaji Wang;Hsuan-Wen Huang;Benchen Zhang;F. Menq;K. Nakshatrala;Y. Mo;K. Stokoe
本研究探讨了新型超材料屏障和地基在减轻从振动源向周围土壤传播的波方面的性能。主动隔振系统是一种靠近振源设置的波屏障，用于减少结构上的振源向周围土壤辐射的波。本研究报告的有效性，提出的隔离系统使用主动激励场测试，从而扩大了被动隔离以外的波屏障的适用性。测试屏障是填充有分层周期性超材料的沟槽屏障，该超材料由聚氨酯和钢筋混凝土（RC）的交替层组成。为了进行比较，还在一个空战壕上进行了测试。利用安装在钢架顶部的移动的振动台模拟主动振源。通过机械地重新定向振动筛，可以在所有三个方向（垂直、水平直列和水平交叉线）上进行主动隔离测试。使用三维（3D）地震检波器和3D加速度计监测地表、周期性障碍物、地基和钢框架上的运动。的隔离行为在各种激励频率和激励方向上的障碍的长度，填充材料，和障碍的总数量的影响进行了研究。测试还包括波屏障与基于超材料的周期性基础一起使用的情况。实验研究表明，安装在钢框架顶部的振动筛产生的振动有效地抑制了基于超材料的基础。在一定的频率范围内，周期性势垒的性能优于空沟槽。隔浪性能随着屏障长度的增加而提高。这项研究为未来建筑物或其他振动敏感设施中周期性屏障和周期性基础的设计提供了基准。
This study investigates the performance of novel metamaterial-based barriers and foundation on mitigating waves transmitting from a vibrational source to the surrounding soil. An active isolation system is a wave barrier built close to the vibration source to reduce the wave radiating from the source of vibration on the structure to surrounding soil. This research reports the efficacy of the proposed isolation system using an active excitation field test, thereby expanding the applicability of such wave barriers beyond passive isolation. The test barrier is a trench barrier infilled with a layered periodic metamaterial that is composed of alternating layers of polyurethane and reinforced concrete (RC). Tests are also conducted on an empty trench for comparison. A mobile shaker mounted on top of a steel frame is utilized to simulate an active vibration source. By mechanically reorienting the shaker, active isolation tests can be conducted in all three directions (vertical, horizontal inline, and horizontal crossline). Motions on the ground surface, periodic barrier, foundation, and steel frame are monitored using three-dimensional (3D) geophones and 3D accelerometers. The effects of the barrier length, the infilled material, and the total number of barriers on the isolation behavior at various exciting frequencies, and excitation directions are investigated. Tests also include the scenario where the wave barrier is used along with a metamaterial-based periodic foundation. Experimental studies show that vibrations generated from the shaker mounted on top of the steel frame are effectively restrained by a metamaterial-based foundation. The performance of the periodic barriers is better than that of an empty trench within certain frequency ranges. The wave isolation performance is enhanced with the increasing barrier length. This research provides the benchmark for the future design of periodic barriers and periodic foundations in buildings or other vibration-sensitive facilities.