任意排列的固定刚性桩屏障对SH波的多重散射

引入任意排列、任意半径的刚性圆柱体对声波或电磁波的多重散射解,对于平面SH波入射下刚性桩隔振屏障的散射问题提出新的有别于以往只考虑单重散射的求解方法--多重散射法.散射波可以表示为无限多重散射的叠加.每根桩的第1重散射即通常的单重散射,第2重散射可以表示为该桩被其余桩的第1重散射波所激发的散射波之和,后续的散射重数以此类推.将所有桩的无限重散射叠加,即求得SH波入射下任意排列、任意半径固定刚性桩多重散射的精确解.在算例中引入量纲一位移的概念,即屏障后总波场引起的位移幅值与入射波在该处引起的自由场位移幅值的比值,绘制了单排等间距、等半径桩屏障后一定范围内的量纲一位移等值线图、屏障后某处的量纲一位移图及透射系数图,分析了散射重数、桩间距和桩数对屏障隔离效果的影响.

Multiple scattering of plane SH wave by arbitrary configuration of rigid pile as barrier for vibration isolation

A new method was established by introducing the multiple scattering of plane acoustic or electromagnetic wave by an arbitrary configuration of parallel cylinders.The method differs from the past ones to solve the problem of plane SH waves scattered by rigid piles as barriers for vibration isolation.The first order of scattering fell back on the single scattering,and the second order resulted from the excitation of each pile by the first order of scattering induced by remaining piles;and so on the successive order could be done in the same manner.The scattered wave was expressed as an infinite sum of various orders of scattering.Thus,the formal solution was obtained.By introducing the normalized displacement amplitude,which means the ratio of total wave field displacement amplitude to incident wave field displacement amplitude,the contour of normalized displacement amplitude and a particular transmissibility index figure were analyzed.The influences of the variation of scattering orders,separations between piles and pile number on the piles as barriers for vibration isolation were investigated.