Simulation Of Laser Thermoelastically Excited Ultrasonic And Analysis Of Chinese Whisper's Acoustic Characteristics

In this paper,we analyzes laser-excited ultrasonic of the thermo-elastic mechanism and establishes a theoretical model suitable for exciting ultrasound in solid samples(metallic and non-metallic).Based on this,it stimulates laser pulse irradiation on the surfaces of aluminum and silicon discs by using COMSOL.The physical phenomena of forming ultrasonic waves are simulated.Based on COMSOL Multiphysics,the temperature field is simulated to simulate the interaction process laser pulse forced on aluminum and silicon,and the temperature field of the laser in the material is simulated.On this basis,by using COMSOL,the finite element analysis model for laser excitation of ultrasonic waves in aluminum plates and silicon plates was established.The intrinsic mechanism of light-to-heat conversion is obtained by analyzing the results of the coupled thermal-solid-acoustic and other physical fields.This photo-thermal conversion for the thermo-acoustic effect can excite the ultrasound,which ultimately results in a specific process of photo-thermal-acoustic conversion.By using the power spectrum estimation method to trace the peak trajectory,the propagation characteristics of the ultrasonic waves excited in aluminum and silicon materials were analyzed,and the formation mechanism of different forms of ultrasonic waves excited under different conditions was analyzed.The research results can provide theoretical basis and simulation basis for the study of laser ultrasonic,especially laser-induced Lamb wave,and provide some theoretical references for the formation and propagation characteristics of ultrasonic waves.As a basic method for extracting signal peaks,the power spectrum estimation method is applied to extract a voiced formant,and the acoustic characteristics of the voice signal are analyzed.The acoustic characteristics of whisper and normal voices are different,and the length and formant characteristics of the ear and normal sounds are compared by statistical methods.The formants are obtained.The law of change is the peaks to the high-frequency region shift toward,and the bandwidth becomes wider.The research results can provide experimental support for whisper processing,recognition and conversion.