Sound transmission loss of sandwich plate with pyramidal truss cores

This paper presents the theoretical model of sandwich plate with pyramidal truss cores to investigate the acoustic property of transmission loss. The two-dimensional periodic model is established based on the assumption that the trusses are regarded as Euler-Bernoulli beams. The fluid-structure interaction is considered by imposing velocity continuity condition at fluid-structure interfaces. The periodic governing equations are derived by using space harmonic expansions and the principle of virtual work. Meanwhile, the practical specimens are fabricated by slitting and snap-fit assembly to conduct sound insulation experiment via standing wave tube method. The theoretical result shows satisfactory agreement with experimental data. The numerical discussions are conducted to demonstrate the effects of incident angles and topological parameters which should be helpful for practical design.