Analysis And Test Of Sound Absorption And Sound Insulation Performance Of Multi-Layer Composite Materials

With the improvement of living standards,people focus on the quality of life is becoming more and more high,as one of the three big pollution,noise pollution continues to cause harm to people’s physical health.The control of noise become the current research topic,many scholars focus on the route of transmission of noise to cut off the noise transmission way.Using the sound absorption mechanism and sound insulation mechanism of the material to achieve noise reduction,the commonly used material with porous materials,homogeneous,micro perforated panel board,composite materials.The single material is difficult to achieve good noise reduction effect of complex noise.When the formation of multi-layer composite by combining multi-layer materials can effectively reduce the noise in a wide band.Based on the equivalent fluid model to analysis the sound-absorbing performance of melamine foam,the acoustic parameters were obtained by experimental testing and parameter inversion.Analyzing the acoustic performance of porous sandwich plate and the lattice structure.The main research contents of this paper are as follows:Firstly,the acoustic characteristics of multi-layer composites such as porous materials,plates,perforated plates and lattice structures are summarized.Analyzing the sound absorption mechanism of various kinds of sound absorption materials.Secondly,the acoustic parameters of melamine porous materials were reverse-deduced and the acoustic absorption performance was analyzed.Based on JCA equivalent fluid model to study the sound absorption performance of melamine foam,the flow resistance and sound absorption coefficient of melamine foam were tested by flow resistance meter and impedance tube test,using the genetic algorithm to reverse the acoustic parameters.The influence of back cavity thickness,acoustic incident angle,material thickness and other factors on the sound absorption performance of melamine foam was analyzed.Based on the Sobol sensitivity method to analyze the sensitivity of parameters in JCA model and to analyze the sound absorption performance of multi-layer porous materials.Then,analyzing the sound insulation performance of porous sandwich plate.Using the finite element method to analyze the sound insulation of cavity double-layer plate,verified by theory and experiment,analyzes the panel thickness,air layer thickness,the material of panel on the effect of sound insulation performance of double-layer plate cavity,analyzes the sound insulation properties of porous material sandwich plate,analyzes the effect of flow resistance rate,the location of the porous materials on the sound insulation performance,optimizes the thickness of porous materials in the sandwich plate.Finally,based on the bandgap properties to analyze periodic lattice structures,analyses the bandgap characteristics of three traditional lattice structures,the narrow bandgap of the traditional lattice structure is not good for vibration reduction effect,two kinds of new type of lattice structure was designed.After size optimization,it has good bandgap characteristics for low and medium frequency bands,and the limited size of the lattice sandwich plate is analyzed on sound insulation performance.