Research Of Wave Field Snapshots In 2D Ultrasonic Physical Simulation

The wave-field snapshots can clearly and visually show the temporal and spatial images of the seismic waves in the medium,and the response characteristics(wave field characteristics)between the geological factors such as tectonics,physical properties and lithology under complex conditions is of a great help,and wave field characteristics in the field of seismic exploration is essential to explain the basis of information.Although the numerical simulation is still the main method to obtain the time-space wave propagation of seismic wave due to the limitation of the physical simulation method,the importance and irreplaceability of the physical simulation in the understanding and research of the seismic wave field have been to promote the development of geophysicists A method of obtaining a wavefront snapshot by physical simulation.Based on the theory of two-dimensional seismic model,the thickness of the two-dimensional model used in the experiment is studied by combining the first Fresnel zone radius theory(transverse resolution)and the observation condition(excitation sensor size).Then based on the basic theory of seismic physics experiment,the ultrasonic physical experiment observation system based on virtual instrument technology is used to construct the two-dimensional homogeneous media model and the two-dimensional transverse heterogeneous media model by using the designed observation scheme for wave field snapshot data acquisition.And the measured experimental data were processed by the prepared data processing program.Finally,the two-dimensional wavefield snapshot was drawn with the processed data and the frequency of the Rayleigh surface wave recorded by the near-free surface was measured by the method.And the corresponding numerical simulation results were compared and analyzed to verify the feasibility and credibility of the experimental method.Finally,a two-dimensional wavefield snapshot of the uniform half-space and transverse non-uniform half-space model is obtained.The wave-field snapshots and the near-free surface recorded Rayleigh wave characteristics are compared with the results of the corresponding two-dimensional numerical simulation,and the two are well consistent with the experimental observation and processing of the two models,which verifies the feasibility and credibility of the ultrasonic wave method.The results show that the proposed physical simulation method has the advantage of visually revealing the spatiotemporal response characteristics of the whole-wave image in two-dimensional complex media.