Vibro-acoustic Modeling And The Parametric Study Of Carbon Fiber Composite Panel Structures

Compared with traditional homogeneous material plates,carbon fiber composite plates have excellent mechanical properties such as light weight and high strength,so they are widely used in aerospace,high-speed rail and automobile cabin structures.Since the carbon fiber composite panel is lighter,it is easy to generate large acoustic radiation under the excitation of environmental vibration and noise.The carbon fiber composite board is formed by extrusion lamination of multi-layer boards with different fiber laying directions,which results in complex constitutive relationship and huge calculation of vibration sound,and it is difficult to understand the relationship between the vibrating characteristics of composite sheets and the lamination design parameters.It restricts the vibrating optimization design of carbon fiber composite plates.Therefore,it is of great engineering significance to carry out the vibration characteristics simulation and parameter research of carbon fiber composite plates.In this paper,the multi-layer symmetrically laid carbon fiber composite board is used as the research object to simulate the vibration characteristics of the composite board.Firstly,based on the classical laminated board modeling theory,the calculation formula of the equivalent stiffness coefficient of the composite board is derived,and the composite board is realized based on the equivalent stiffness.Equivalent single layer simulation of dynamic characteristics.Taking the 16-layer carbon fiber composite rectangular plate with solid boundary as an example,the effectiveness of vibration calculation for equivalent single-layer modeling is verified by finite element simulation and modal test.On this basis,the influence of the number and area of the ply on the computational time-consuming of traditional modeling and equivalent single-layer simulation is analyzed and compared.The results show that the equivalent single-layer simulation can greatly improve the accuracy of vibration response calculation.Reduce the calculation time.Both theoretical and finite element simulations show that this equivalent single layer modeling is suitable for the case where the layup is symmetrical with respect to the center plane of the plate.Secondly,the Rayleigh integral method and impedance method are combined with the modal decomposition method to analyze and calculate the acoustic radiation characteristics and sound insulation characteristics of the composite plates.The vibration modes of the carbon fiber composite plates are discussed.The mechanism of influence on the acoustic radiation characteristics of the board and the sound insulation characteristics.Studies have shown that there are a few dominant vibration modes that determine acoustic properties in the low frequency range of carbon fiber composite plates.Based on the theoretical relationship between the dominant vibration mode and the design parameters of the composite plate,the acoustic characteristics of the carbon fiber composite plate can be effectively improved by optimizing the design parameters of the composite plate.Finally,a model of vibration simulation of carbon fiber composite plates was established.Through the finite element simulation calculation and comparison,the influence mechanism of some key parameters of the laminated structure on the overall vibration characteristics of carbon fiber composite plates,including laminated structure,was further discussed.Specific parameters(such as fiber laying parameters)and general material parameters(such as material property parameters).The calculation results show that the number of layers in the fiber direction has the greatest influence on the overall vibration characteristics of the carbon fiber composite board.The fiber direction arrangement order and axial elastic modulus have a great influence on the natural frequency value,while the transverse elastic modulus and shear mode The amount has a relatively small effect on the overall vibrating characteristics.In this paper,the simplified equivalent modeling method for vibration simulation of carbon fiber composite plates is studied.The influence mechanism of key design parameters of composite plates on the overall vibration characteristics is analyzed.The vibration modeling and optimization design of carbon fiber composite plates is carried out.Provide a theoretical basis.