Measurement And Calculation Of Sound Absorption And Insulation Of Vehicle-used Multi-layered Panel Materials

Nowadays people pay more and more attention to the NVH performance of vehicles.Controlling vehicle noise is an essential part when designing a car.For automotive interior trims,like dash or carpet,comparing to traditional sandwich insulation system,the ABA(absorber-barrier-absorber)and dissipative structures are lighter in the condition of same thickness and same sound absorption and insulation performances.At present,when developing double felt,ABA and dissipative structural interior trims,several groups of experimental samples are made,the absorption coefficient and sound insertion loss of each experimental sample are tested,and then the experimental results are compared in order to pick out a suitable scheme which costs a lot of time and money.The measurement and calculation methods for sound absorption and insulation of multi-layered panel materials including double felt,ABA and dissipative materials are proposed.Firstly,the sound absorption coefficients and the insertion losses of three kinds of multi-layered panel materials are measured with Alpha cabin equipment and anechoic-reverberation room,respectively.To calculate the sound absorption and insertion loss of multi-layered panel materials,then the sound absorption,flow resistivity and porosity of the single-layer materials are measured.Thirdly,the sound absorption coefficient and insertion loss of the multi-layered panel materials are estimated using the software.When calculating the sound absorption coefficient and insertion loss of ABA structural panel materials,the felt is chosen elastic modal in order to considering the force between the film and the felt.When calculating the sound absorption coefficient and insertion loss of dissipative structural panel materials,the perforated film is chosen perforated screen modal.The film’s flow resistivity is tested and its porosity is calculated.Comparison of measurements and calculations show reasonable agreement for sound absorption coefficient and insertion loss results.The results of the study will be able to guide the design of the three kinds of structures which will promote the application of the three kinds of structures in interior trims.At the same time,the research and modeling methods of this paper can also be used to analyze the characteristics of other acoustic structures.