In the present study, under the assumption of small amplitude water wave theory and structural response, effect of bed undulation on the wave interaction with a combination of flexible porous barrier and a flexible floating plate, is studied. The flexible porous barrier is modelled using the porous wave maker-theory while the elastic floating plate is modelled using thin plate theory. The physical problem is handled for solution using eigenfunction expansion method by matching pressure and velocity at interface boundaries while finite difference method is used to deal with modified mild-slope equation. In the present study, two types of plate configurations are namely (a) finite plate and (b) semi-infinite plate. To understand the role of undulating seabed, wave and structural parameters, in attenuating wave force and plate deflection, numerical results are computed and compared with available literature. It is found that full wave reflection occurs for certain critical angle and wave force acting on the barrier vanishes for the same critical angle for the semi-infinite plate case while the wave reflection tends to attain maximum value at critical angle for the finite case and these maximum value increases with the increase of plate length. It is observed that less wave reflection occurs for sloping bed profile compare to rest of the bed profile. The study reveals that positioning a barrier between plate and undulated region, helps in the reduction of plate deflection significantly. As special case, wave interaction problem with a finite floating elastic plate is studied experimentally and the experimental result has shown good agreement with the numerical result. The findings of the present study are likely to be of immense help in the design of various types of marine structures for protecting very large floating structures (VLFS). The present theory can be extended to handle large class of acoustic wave interaction problems with flexible porous structures.

中文翻译：

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波浪形底部与浮动柔性板耦合柔性多孔屏障对波浪相互作用的影响

在本研究中，在小振幅水波理论和结构响应的假设下，研究了床层起伏对柔性多孔屏障和柔性浮板组合的波浪相互作用的影响。柔性多孔屏障使用多孔造波器理论建模，而弹性浮板使用薄板理论建模。物理问题的求解采用特征函数展开法，通过匹配界面边界处的压力和速度，而有限差分法用于处理修正的缓坡方程。在本研究中，两种类型的板配置是（a）有限板和（b）半无限板。了解起伏的海床、波浪和结构参数在衰减波浪力和板块挠度方面的作用，计算数值结果并与现有文献进行比较。发现对于一定的临界角会发生全波反射，对于相同的临界角，半无限板情况下，作用在屏障上的波力消失，而对于有限情况，波反射在临界角处趋于达到最大值，并且这些最大值随着板长的增加而增加。据观察，与其余的床剖面相比，倾斜床剖面发生的波反射较少。研究表明，在板块和起伏区域之间设置屏障有助于显着减少板块偏转。作为特例，对有限浮动弹性板的波浪相互作用问题进行了实验研究，实验结果与数值结果吻合良好。本研究的结果可能对设计各种类型的海洋结构以保护超大型浮动结构 (VLFS) 有很大帮助。本理论可以扩展到处理具有柔性多孔结构的大类声波相互作用问题。