摘要
波阻板(wave impeding block,WIB)隔振体系是一种有效的振动污染治理措施,虽逐渐被应用在工程实际中,但以往的研究多集中于单相固体均质材料的情形,而对材料特性沿空间连续变化的非均匀固体材料的波阻板隔振性能的研究相对较少.基于功能梯度材料(functionally graded material,FGM)特点,本文提出了以功能梯度波阻板作为隔振屏障的一类新型的地基振动控制体系.考虑在弹性地基内部设置梯度波阻板,基于线弹性理论,利用傅里叶积分变换,根据Helmholtz矢量分解原理,建立了弹性地基在动载荷作用下的回传射线矩阵法(reverberation ray matrix method,RRMM)计算列式.假设梯度波阻板的物理力学性质沿深度方向按幂函数连续变化,采用数值傅里叶逆变换获得了弹性地基的位移和应力等物理量的数值解.通过数值算例,与单相固体均质波阻板进行了对比,并分析讨论了梯度波阻板的材料梯度因子、埋深以及梯度波阻板厚度等物理力学参数对地基隔振性能的影响规律.结果表明,梯度波阻板能有效降低振动的振幅,与单相固体均质波阻板相比,梯度波阻板具有更好的减振隔振效果.地基的位移幅值和应力幅值随着梯度因子的增大而减小.梯度波阻板的隔振效果随着波阻板厚度的增大而提高,而随着梯度波阻板埋深的增大而降低.
Wave impeding block(WIB)vibration isolation system as an e_ective measure for vibration pollution control is applied in practical engineering gradually,but the previous studies mostly focused on the single-phase solid homogenous materials,few research have been on the vibration isolation performance of wave impeding block with materials properties that have a continuous variation along space relatively.Based on the functionally graded material,a new type of foundation vibration isolation system is proposed.Considering setting the graded wave impeding block in the elastic foundation which subjected to surface strip harmonic load,using the Fourier transform and Helmholtz vector decomposition,the calculation formula of reverberation ray matrix method(RRMM)is established for two-dimensional transient response of elastic foundation based on the line elastic theory.Assuming that the material properties of graded wave impeding block have an exponential law distribution along the thickness-coordinate,by using numerical inverse Fourier transformation,the displacement and the stress are obtained.Via numerical examples,the effectiveness of vibration isolation of graded wave impeding block is compared to conventional single phase solid homogenous wave impeding block,and the influences of physical and mechanical parameters including the gradient factor,the depth and the thickness of graded wave impeding block are analyzed.The results show that the graded wave impeding block can effectively reduce the vibration amplitude,and compared with the single phase solid homogenous wave impeding block isolation system,graded wave impeding block isolation system has better effect.The amplitude of displacement and stress is decreased with the increase of gradient factor.The effect of vibration isolation of graded wave impeding block improved with the increased of the thickness,but reduced with the increasing of the embedded depths.
作者
马强
周凤玺
刘杰
Ma Qiang;Zhou Fengxi;Liu Jie(School of Civil Engeering,Lanzhou University of Technology,Lanzhou 730050,China;School of Trac and Transportation,Lanzhou JiaoTong University,Lanzhou 730070,China)
出处
《力学学报》
EI
CSCD
北大核心
2017年第6期1360-1369,共10页
Chinese Journal of Theoretical and Applied Mechanics
基金
国家自然科学基金资助项目(51368038)
关键词
地基振动控制
弹性地基
动力响应
梯度波阻板
回传射线矩阵法
ground vibration control
elastic foundation
dynamic response
graded wave impeding block
reverberation ray matrix method
