Simulation Of Mobile Phone Loudspeaker Based On Finite Element Method

The simulation of audio equipment such as mobile phone speakers is important for the input and output optimization of audio signals and the development of audio signals in human-computer interaction.However,the design of mobile micro-speakers involves many aspects,among which the multi-physics coupling in the sound process of mobile phone speakers is quite important.Therefore,it is very important to establish a virtual physical model of the mobile phone speaker based on the finite element simulation analysis software to simulate based on the speaker model and verify the design of the mobile phone speaker based on the simulation results and evaluate the performance of the mobile phone speaker.The simulation research of audio equipment such as loudspeakers based on finite element analysis software can promote the development and construction of the audio equipment design industry to a certain extent,and can also play a role in the development and progress of mobile electronic devices,such as mobile phones,and human-computer interaction.The main research content of this paper is to use the finite element simulation software COMSOL Multiphysics and MATLAB to realize the full-link simulation of the mobile phone speaker model,and to carry out time domain simulation research on the mobile phone speaker,and adjust the structure and material properties of the mobile phone speaker in the simulation to apply to actual equipment design.This paper discusses the multiphysics physics equations of mobile phone speakers based on finite element analysis,and analyzes the differential equations or partial differential equations and their boundary conditions of the magnetic field,mechanics,acoustics and thermal parts to be solved in the finite element simulation of mobile phone speakers.According to the multi-physics coupling research in the sounding process of mobile phone speakers,the three kinds of speaker simulation coupling ideas are analyzed,and the single item decoupling method is selected to simulate the mobile phone speaker model.The mobile phone speaker model is imported in COMSOL,the material parameters and mesh division are set,and the magnetic circuit of the speaker is simulated and solved.The curve of the force factor BL with the vibration of the voice coil is obtained,and the influence of nonlinear distortion is analyzed.Then,in MATLAB,the script is called to call COMSOL to interpolate the actual audio signal obtained by inputting the electrical simulation in COMSOL,and the joint simulation of MATLAB & COMSOL is carried out.The simulation results analyze the sound pressure of the voice coil driving force and the listening point,and use the three-dimensional drawing to visualize.The changes of sound pressure inside the mobile phone speaker are analyzed,and the sound pressure results illustrate the feasibility of full link simulation.At the same time,the glitch signal is analyzed by full-link simulation,and the result verifies the accuracy of full-link simulation.The single-tone time-varying signal input to the mobile phone speaker is simulated,and the sound pressure variation and total harmonic distortion are analyzed.Harmonic distortion test is performed on the actual mobile phone speaker,and the total harmonic distortion curve with the input frequency is obtained.Then,the multi-frequency scan calculation is added in the simulation study to obtain the total harmonic distortion curve with frequency,and the total harmonic will be simulated.The comparison between the distortion curve and the measured data verifies the accuracy of the time domain simulation method and its distortion analysis,and adjusts the material properties to assist the design of the actual mobile phone speaker.Finally,based on the electromagnetic loss obtained by the magnetic analysis of the mobile phone speaker,the model is thermally simulated,and the internal temperature distribution of the speaker is obtained.The selection of the speaker structure material is given.