This study investigates the effects of fluid–structure and soil–structure interaction on the free vibration response of functionally graded sandwich plates. To this aim, an exemplary problem is analyzed, whereas a metal/ceramic sandwich plate is placed at the bottom of a tank filled in with fluid. Two cases are considered: (i) soft core, i.e., a sandwich plate with metal core and ceramic skins, and (ii) hard core, i.e., a sandwich plate with ceramic core and metal skins. In both cases, the skins are modelled as suitable functionally graded materials (FGMs). The soil is modelled as a Pasternak foundation. The free vibration analysis is carried out according to the extended higher order sandwich plate theory (EHSAPT). The fluid is assumed to be inviscid, incompressible, and irrotational. Hamilton’s principle is exploited to deduce the governing equations and the corresponding boundary conditions. The Rayleigh–Ritz method with two-variable orthogonal polynomials is used to compute the natural frequencies of the sandwich plate. The adopted approach is first validated through comparison with results published in the literature. Then, the effects are studied of several parameters on the dynamic response of the system.

这项研究调查了流体-结构和土壤-结构相互作用对功能梯度夹层板自由振动响应的影响。为了这个目的，分析了示例性问题，而金属/陶瓷夹层板被放置在填充有流体的罐的底部。考虑了两种情况：（i）软芯，即具有金属芯和陶瓷表皮的夹心板，和（ii）硬芯，即具有陶瓷芯和金属表皮的夹心板。在这两种情况下，都将蒙皮建模为合适的功能渐变材料（FGM）。将土壤建模为Pasternak基础。自由振动分析是根据扩展的高阶夹心板理论（EHSAPT）进行的。假定流体不粘稠，不可压缩且无旋转。利用汉密尔顿原理来推导控制方程和相应的边界条件。具有二变量正交多项式的瑞利-里兹方法用于计算夹层板的固有频率。首先通过与文献中发表的结果进行比较来验证所采用的方法。然后，研究了几个参数对系统动态响应的影响。