Analysis And Experimental Study On Sound Insulation Characteristics Of Honeycomb Sandwich Plates With Double-layer Cores

Honeycomb sandwich panels are widely used in aerospace,and many other fields because of their outstanding performances such as excellent light-weight,high strength,stiffness ratio,stability and sound insulation performance,which become an important part of vehicle structures such as airplane and cars.As people's requirements on the noise level become more stringent,more and more focus has been put in the cabin noise problems.It is great significance to study the vibrational and acoustic performance of honeycomb sandwich panels for improving the ride comfort and lower the noise level of the cabin.In this paper,the vibration characteristics and sound insulation properties of honeycomb sandwich plates with double-layer cores are theoretically and experimentally studied,and based on this work,the multi-objective optimization design of honeycomb sandwich plates with double-layer cores has been done.Firstly,the influence of structural parameters on the natural frequency of sandwich plates with double-layer cores have been analyzed by the established inherent frequency theory model of sandwich plates.The inherent frequency of honeycomb sandwich plates with single-layer core/double-layer cores have been calculated by cite the orthogonal anisotropic multi-layer sandwich board theory basis on the Hoff hypothesis.The natural frequency and vibration modes of honeycomb sandwich plate with singlelayer core and double-layer cores have been contrastive analyzed,then the influence of some structure parameters on the natural frequency of the honeycomb sandwich plates are analyzed.The results show that: the thickness of the face sheet and core,young's modulus of the face sheet have great influence on the natural frequency.Secondly,the influence of structure parameters on the sound transmission loss are analyzed by the established STL model of the honeycomb sandwich panel with doublelayer cores.Considering reverberation incident sound field,the sound transmission loss of limited size,rectangle honeycomb sandwich plates with double-layer cores have been calculated under simply supported conditions.The sound transmission loss of honeycomb sandwich plates with single-layer core and double-layer cores have been contrastive analyzed,then the influence of some structure parameters on the STL of the honeycomb sandwich plates are analyzed.The results show that: the thickness of the face sheet and core,the density of the face sheet and core have great influence on the natural frequency.Thirdly,the transmission loss of honeycomb sandwich plates with single-layer core and double-layer cores are tested and contrastive analyzed by using the impedance tube.By processing and testing the samples of different specification,the influence of the thickness of core and the side length of hive on the STL of the honeycomb sandwich plates are analyzed.The results show that: increasing the thickness of core layer can significantly increase the sound insulation performance of honeycomb sandwich plates,for honeycomb sandwich plates with single-layer core,the smaller side length of hive have better sound insulation performance.Finally,the double-objective optimization and triple-objective optimization design of honeycomb sandwich plates with double-layer cores have been done by using the genetic algorithm.It is assumed that the total thickness of honeycomb sandwich plates with double-layer cores is constant,set the thickness of core,the density of core layer and face sheet as design variables.The optimized Pareto solutions are obtained by the numerical simulation.