Ni Yu, Shi Zhifei
Institute of Smart Materials and Structures, School of Civil Engineering, Beijing Jiaotong University , Beijing 100044, People's Republic of China.
Philos Trans A Math Phys Eng Sci. 2024 Sep 9;382(2278):20240020. doi: 10.1098/rsta.2024.0020. Epub 2024 Jul 29.
Periodic wave barriers (PWB) open a new window for vibration mitigation. However, the Doppler effect is rarely considered in most of the previous investigations on the control of ambient vibration induced by moving loads. This article reveals the significance of the speed and frequency of moving loads on surface waves, and improves the design method of PWB for ambient vibration reduction and isolation. First, the theoretical expression of the main frequency band of surface waves propagating in an elastic half-space caused by a moving load was obtained. Comparisons with the numerical results under three different types of traffic loads were also conducted and good agreement was found. Second, the theoretical expression and numerical results were verified by experimental studies. Some inherent properties of wave propagation caused by a moving load in an elastic half-space were also revealed. Third, two kinds of PWBs, i.e. periodic empty trench barrier and periodic pile barrier, were introduced to mitigate wave propagation. It has been confirmed that if the attenuation zones of PWB match the target frequency bands given by the theoretical expression, good vibration mitigation can be achieved. This article is part of the theme issue 'Current developments in elastic and acoustic metamaterials science (Part 1)'.
周期波屏障(PWB)为振动减缓开辟了一扇新窗口。然而,在以往大多数关于移动荷载引起的环境振动控制的研究中,很少考虑多普勒效应。本文揭示了移动荷载的速度和频率对表面波的重要性,并改进了用于环境减振和隔振的PWB设计方法。首先,得到了移动荷载作用下弹性半空间中表面波主频带的理论表达式。还与三种不同类型交通荷载下的数值结果进行了比较,发现吻合良好。其次,通过实验研究验证了理论表达式和数值结果。还揭示了弹性半空间中移动荷载引起的波传播的一些固有特性。第三,引入了两种周期波屏障,即周期性空沟屏障和周期性桩屏障,以减缓波传播。已经证实,如果周期波屏障的衰减区与理论表达式给出的目标频带匹配,就可以实现良好的减振效果。本文是主题为“弹性和声学超材料科学的当前发展(第1部分)”的一部分。