371 results about "Shear waves" patented technology

The invention provides a multi-mode ultrasonic fusion pressure vessel weld defect nondestructive testing method and system, and relates to the technical field of nondestructive testing. According to the method, geometric parameters of a welding seam are obtained through three-dimensional laser scanning, and an optimal scanning parameter set is generated; driving ultrasonic phased array equipment to scan for one time and synchronously acquire shear wave full-matrix capture and longitudinal wave linear scanning data; performing energy flow angular spectrum analysis and envelope analysis on the bimodal data, extracting defect feature parameters and constructing a three-dimensional feature tensor; carrying out multi-dimensional feature fusion by adopting Tucker decomposition, and enhancing a core tensor through physical modeling; generating three types of defect indication diagrams including a defect existence possibility diagram, a defect relative scale diagram and a defect space orientation diagram from the enhanced feature tensor; and the three types of indication diagrams are visually presented for comprehensive interpretation of detection personnel. Through multi-modal data fusion and physical modeling enhancement, the defect identification accuracy and detection efficiency are remarkably improved, the false alarm rate is reduced, and reliable technical support is provided for pressure vessel welding seam safety detection.

The invention provides an airfield pavement detection method based on an earthquake background noise imaging technology, and relates to the technical field of airfield pavement detection. Comprising the following steps: acquiring seismic background noise data of an airport pavement to be measured; preprocessing the seismic background noise data to obtain preprocessed noise data; carrying out cross-correlation calculation on the preprocessed noise data and carrying out empirical Green function extraction; according to the empirical Green function, a surface wave group velocity frequency dispersion curve is extracted by adopting spatial autocorrelation and multiple filtering methods; inverting shear wave velocity distribution of each layer of the pavement based on the surface wave group velocity dispersion curve, and constructing a three-dimensional velocity model; determining a shear wave velocity distribution diagram according to the three-dimensional velocity model; and determining a detection result of the airfield pavement to be detected according to the transverse wave velocity distribution diagram. According to the invention, the problems of low detection precision and poor real-time performance of a common detection technology in the prior art are solved.

The invention discloses a transmission tower vulnerability analysis method and system based on seismic simulation, and belongs to the technical field of electric power facility disaster prevention, and the method comprises the steps: correcting bedrock seismic oscillation parameters based on equivalent shear wave velocity, and generating a high-precision earth surface PGA distribution diagram; automatically positioning a key node layer through eigenvalue decomposition, reducing the order of the three-dimensional model of the power transmission tower into a two-dimensional series multi-degree-of-freedom model, and outputting a layer mass vector, a condensation stiffness matrix and rod piece bending stiffness; performing time-history analysis by using the corrected PGA-driven reduced-order model to generate an earthquake damage probability; the multi-source remote sensing data and the PGA are fused, the landslide space probability is output through a deep learning model, and the impact strength and the landslide kinetic energy are calculated to judge the landslide damage probability; and based on the dual-threshold condition triggering probability union set, calculating a comprehensive damage probability, and generating a three-dimensional vulnerable curved surface. According to the method, the problems of high missing report rate and low calculation efficiency of single disaster assessment are solved, and minute-level accurate early warning of the composite disaster risk of the power transmission tower is realized.

The invention provides a tissue viscoelasticity calculation method and system based on wavelet transform, and the method comprises the steps: exciting and generating shear waves at a target region of a tissue, and extracting shear wave information; carrying out wavelet transformation on the shear wave information, and extracting frequency domain information in the shear wave information, so as to obtain time-frequency domain information of shear waves; taking any point on the transverse tangent plane as a target point, and performing cross-correlation between the time-frequency domain information of the target point and the time-frequency domain information of the other points by using a cross-correlation algorithm to obtain phase differences between the target point and the other points under different frequencies; determining phase velocities of shear waves under different frequencies according to phase differences between the time-frequency domain signals of the target point and the time-frequency domain signals of other points under different frequencies; and fitting the phase velocities of the shear waves under different frequencies to obtain a viscosity value and an elasticity value corresponding to the target area of the tissue. The method does not need to collect data for many times, reduces errors caused by data collection, and improves the mechanical characteristic calculation precision of the tissue.

The invention discloses a tight sandstone gas reservoir logging scale fracture development evaluation method, and relates to the field of earth exploration physics, and the method comprises the steps: carrying out the inversion based on a complex pore structure high-angle fracture type rock physical model and actual logging data through employing a simulated annealing particle swarm algorithm, and obtaining two groups of fracture density parameters in a well; respectively calculating crack density identification factors under different rotation angles; based on a correlation coefficient between the Poisson impedance and the fracture density under different rotation angles, determining an optimal rotation angle when the correlation coefficient reaches a maximum value; calculating a crack density identification factor under the optimal rotation angle by combining longitudinal wave impedance and transverse wave impedance data; and applying the fracture density identification factor under the optimal rotation angle to actual logging data, and representing fracture development. The method can effectively distinguish and quantify multiple groups of high-angle fractures developed in the tight sandstone reservoir, significantly improve the prediction precision and reliability of the fractured reservoir, and provide a key basis for reservoir sweet spot prediction and well location deployment.

One or more embodiments of the invention provide a Scholte wave frequency dispersion curve adaptive inversion method and a related device, and the method comprises the steps: obtaining and processing the original seismic data of a target seabed, and obtaining a Scholte wave frequency dispersion curve; constructing an initial shear wave velocity model through linear inversion based on a Schlte wave frequency dispersion curve; and performing fitting optimization on the Schlte wave frequency dispersion curve based on the initial shear wave velocity model to obtain a two-dimensional shear wave velocity profile. According to the technical scheme, the problem that a traditional linear inversion method depends on an initial model is solved, the calculation efficiency is remarkably improved, the problem of local extremum is avoided, and an automatic high-precision inversion solution suitable for batch data processing is provided for submarine seismic exploration.

The invention belongs to the technical field of medical imaging, and provides a tissue stress measurement method and system based on a reverberation shear wave field, and the method comprises the steps: applying steady-state harmonic excitation, and obtaining the reverberation shear wave field of a target tissue; determining a stress direction according to the prior information of the target tissue, and constructing a stress direction vector; constructing an analytic operator, and extracting an intermediate characteristic quantity of the reverberation shear wave field; and according to the intermediate characteristic quantity, combining stress direction inversion to reconstruct spatial stress distribution. According to the method, a complex reverberation wave field is modeled into superposition of multi-direction propagation wavelets by utilizing anisotropic propagation characteristics of shear waves and combining a traveling wave expansion model, and characteristic quantities related to local stress and material parameters are directly extracted from the reverberation wave field by designing a wave field operator with physical significance; the three technical problems existing in a traditional shear wave elastic imaging technology are solved, the dependence of a traditional method on a single propagation direction and wave pattern controllability is broken through, and in-situ, in-vivo and non-invasive quantification is achieved.

The invention discloses a tight sandstone shear wave prediction method based on a fluid saturation dual fracture coupling model, and relates to the technical field of earth exploration physics. According to the method, a saturated rock physical model containing two groups of vertical orthogonal fracture fluids is constructed based on a Chapman multi-scale fracture medium theory framework, and an inter-fracture fluid mass distribution function is introduced to construct a dual-fracture coupling model based on fluid saturation. According to the method, conventional logging information is used as prior information, a rock physical model is used as a drive, an actual longitudinal wave speed and a simulated transverse wave speed are used as nested constraint conditions, a transverse wave speed prediction objective function is constructed, the tight sandstone transverse wave speed and the reservoir multi-group fracture density are estimated, a simulated annealing particle swarm optimization algorithm is introduced, and the reservoir multi-group fracture density is predicted. And the global optimization capability and the local convergence efficiency are enhanced. According to the method, the shear wave velocity prediction error can be effectively reduced, meanwhile, reservoir microstructure parameters are provided, and effective support is provided for reservoir fluid property judgment, lithology accurate recognition and underground fracture system quantitative description.

This invention discloses a quantitative evaluation method for the homogeneity of lightweight aggregate concrete based on rapid ultrasonic testing, belonging to the field of engineering materials testing technology. The method includes: S1, obtaining the shear wave velocity and longitudinal wave velocity at multiple test points of a series of lightweight aggregate concrete reference specimens; S2, calculating the shear modulus and bulk modulus at each test point of each reference specimen; S3, calculating the elastic modulus at each test point of each reference specimen; S4, constructing a relationship between the lightweight aggregate volume content, shear wave velocity, and longitudinal wave velocity based on the elastic modulus obtained in step S3; S5, obtaining the shear wave velocity and longitudinal wave velocity at each test point of the specimen to be tested, and calculating the lightweight aggregate volume content at each test point of the specimen to be tested based on the relationship; S6, evaluating the homogeneity of the specimen to be tested based on the lightweight aggregate volume content calculated in step S5. This invention solves the technical problem of insufficient accuracy in ultrasonic testing results for the homogeneity of lightweight aggregate concrete.

The invention provides a frictional wear acoustic emission detection method based on a shear wave sensor, which comprises the following steps: determining the frequency response range of the shear wave sensor and designing the shear wave sensor according to the requirements of the material characteristics of a friction pair, different working condition scenes and monitoring precision; a designed shear wave sensor is installed on one side of a non-contact surface of a friction pair in a self-transmitting and self-receiving mode, and a frictional wear monitoring system is built by combining with the shear wave sensor; shear wave acoustic emission signals and mechanical signals collected in a frictional wear monitoring system are synchronously stored, collected data are analyzed by adopting a method of combining time domain analysis, frequency domain analysis and time-frequency analysis, a corresponding relation between signal characteristics and frictional wear states is established, and accurate identification of shear damage is realized. According to the invention, the in-situ, real-time and high-precision monitoring of the shear damage in the friction wear process is realized by optimizing the type of the sensor and building a friction wear monitoring system.

The invention discloses a karst detection method based on blasting seismic wave component analysis. According to the method, based on the propagation characteristics of shear waves (transverse waves and S waves) in fluid, a blasting seismic source generated in the tunnel excavation process is used as an active signal source, existence of a karst cave area is preliminarily judged through multi-point synchronous monitoring and analysis of S wave energy proportion changes, arrival time difference, energy distribution and the like of P waves and S waves are analyzed according to the karst cave area, and the karst cave area is determined. The method achieves the recognition and judgment of the spatial distribution characteristics (including the position and the scale) of the karst cave, and finally obtains the specific moisture content of the karst cave in combination with a related theoretical calculation result, thereby achieving the accurate detection of the characteristics of the karst cave in a detection region. According to the method, an excitation source does not need to be additionally arranged, the detection process and conventional blasting construction can be carried out synchronously, and the method has the advantages of being few in measuring point arrangement, easy and convenient to implement, high in efficiency, accurate, small in calculation workload and the like and is suitable for karst detection and geological disaster early warning in the blasting construction period of tunnels such as water conservancy projects and traffic tunnels.

The present disclosure describes ultrasound systems and methods configured to interrogate the stiffness and / or elasticity of a target tissue through shear wave imaging. The systems can be configured to transmit multiple push pulses at different focal depths in the target tissue in a strobe-like fashion. The rapidly transmitted push pulses can generate constructive interference to form shear waves of a composite shear wave. An example system can include a beamformer configured to transmit parameters of a push pulse to a transducer array while receiving new parameters of a push pulse from a controller. The dual transmission and reception of parameters of different push pulses reconfigures the beamformer without interrupting push pulse transmission, thereby minimizing the delay between successive push pulses. The push pulses transmitted according to the disclosed methods can generate a composite shear wave configured to interrogate the tissue with enhanced sensitivity over a wide range of depths.

The invention relates to a method for forming (P1) a primary stack (30) comprising: a supply step (E1) of an initial stack (10) comprising an initial substrate (11) having a front face (Fav) comprising a central zone (Zc) and a peripheral contouring zone (Zdp), and a resonant thin layer (13) of piezoelectric material; and a protection step (E2), in which a protective thin layer (17) is deposited on the initial stack (10) and covering the peripheral contouring zone (Zdp); the protective thin layer (17) being of a material having an acoustic impedance greater than 20 MRayl for longitudinal waves and / or greater than 12 MRayl for shear waves. The invention also relates to a resonant electronic device (100) and a method (P2) for manufacturing a resonant electronic device (100) from such a primary stack (30). Figure 2

The invention relates to the technical field of petroleum geophysical exploration, and provides a reservoir forming period hydrocarbon source rock paleo-pressure quantitative prediction method and system, and the method comprises the steps: solving the stratum denudation thickness based on a mudstone compaction curve extrapolation method; obtaining the thickness of a terrain skeleton, constructing a binary function based on the stratum denudation thickness and the thickness of the terrain skeleton to analyze an approximate solution, and inverting the stratum paleo-burial depth for the logging paleo-burial depth; obtaining the total porosity of the hydrocarbon source rock according to the stratum paleo-burial depth; quantitatively predicting the single well paleo pressure of the hydrocarbon source rock according to the total porosity; the multi-well paleo pressure is obtained based on the single well paleo pressure, interpolation is performed according to the multi-well paleo pressure to obtain the plane paleo pressure, in this way, the accurate well logging compaction trend line is established, the accuracy and reliability of the prediction result are improved by considering the influence of the shear wave speed, and therefore the accuracy of predicting the paleo pressure of the hydrocarbon source rock in the reservoir forming period is improved.

The present application relates to the technical field of medical elastic imaging and material multi-scale mechanical measurement, and particularly discloses an elastic imaging method and system based on a scattering displacement gradient field, which comprises the following steps: generating a scattering displacement field by arranging an excitation device around a target material, measuring an out-of-plane displacement gradient field by using transverse shear interference imaging, selecting a single-frame instantaneous gradient field or a frequency-domain gradient field obtained by time-frequency domain Fourier transform as a target field; obtaining a global shear wave velocity distribution by adaptive sliding window interception, two-dimensional autocorrelation calculation and Rayleigh wave spatial autocorrelation theoretical model fitting, and then reconstructing viscoelastic modulus distribution by using an inversion algorithm. The present application supports single-frame scattering displacement gradient field inversion elastic imaging, can be used without high-frame-rate equipment, has strong anti-environmental vibration interference ability and high system stability, is suitable for scenes with poor isolation conditions, has low cost, high efficiency and high measurement precision, and can meet the requirements of medical clinical diagnosis and material multi-scale mechanical measurement.

Changes in tissue stiffness have long been associated with disease. Systems and methods for determining the stiffness of tissues using ultrasonography may include a device for inducing a propagating shear wave in tissue and tracking the speed of propagation, which is directly related to tissue stiffness and density. The speed of a propagating shear wave may be detected by imaging a tissue at a high frame rate and detecting the propagating wave as a perturbance in successive image frames relative to a baseline image of the tissue in an undisturbed state. In some embodiments, sufficiently high frame rates may be achieved by using a ping-based ultrasound imaging technique in which unfocused omni-directional pings are transmitted (in an imaging plane or in a hemisphere) into a region of interest. Receiving echoes of the omnidirectional pings with multiple receive apertures allows for substantially improved lateral resolution.

A viscoelasticity measurement method and an ultrasonic imaging system, the method comprising: generating a shear wave propagating in a target region of a subject to be measured (S210); transmitting an ultrasonic wave tracking the shear wave to the target region, and receiving an ultrasonic echo returned by the target region to obtain ultrasonic echo data (S220); obtaining tissue motion information in the process of the shear wave propagation according to the ultrasonic echo data (S230); extracting tissue motion target information corresponding to shear waves of at least two different frequencies from the tissue motion information (S240); and outputting the tissue motion target information of the shear waves of the at least two different frequencies, the tissue motion target information being used to reflect a viscous characteristic of the target region (S250). Thus, the viscous characteristic of the tissue is reflected by the tissue motion target information of the shear waves of the at least two different frequencies.

For shear wave imaging with ultrasound, the apparent pulse repetition frequency is increased by combining displacements from different lateral locations. Different combinations based on different shear wave velocities and corresponding time shifts and / or attenuations and corresponding scalings are tested to find a smooth displacement profile for the combination. Once the smooth displacement profile is found, the corresponding shear wave velocity is estimated or determined.

Provided herein is an ultrasound imaging probe comprising: a backing layer; an acoustic stack, the acoustic stack having an interconnect coupled to the backing layer; a transducer array electrically coupled and interconnected and comprising at least one transducer element having a transduction surface, and at least one matching layer having a first side acoustically coupled to the transduction surface, and a second opposite side; and a compound lens including an inner lens having a planar inner side acoustically coupled to the second opposite side of the matching layer and a first non-planar side that is non-planar in height and that is wave-shaped at least in azimuth angle, and an outer lens having a planar outer side acoustically coupled to the second opposite side of the matching layer and a second non-planar side that is non-planar in height and that is wave-shaped at least in azimuth angle. The outer lens has an outer side configured to contact an object or body and a second non-planar side that is non-planar in height and undulating at least in azimuth angle, wherein the first non-planar side of the inner lens is acoustically coupled to the second non-planar side of the outer lens.

The invention provides a site classification method and system based on a regional gradient-Vs30 mapping model, electronic equipment and a storage medium, and relates to the technical field of seismic engineering and site classification.The method comprises the steps that a grid where a drilling point in a to-be-measured area is located is used as a center pixel, a nine-square window is constructed, and a Vs30 mapping model is constructed; and calculating elevation change rates of the central pixel and the adjacent pixels in x and y directions based on the digital elevation data, and further obtaining a terrain slope value through a slope formula. A slope value is converted into a soil layer shear wave velocity predicted value by utilizing a pre-constructed regional gradient-Vs30 mapping model, and the model is optimized through local drilling data, so that the regional applicability is improved. And finally, according to the mapping relationship between the interval and the site category, classifying the predicted values and generating a site classification spatial distribution diagram. According to the method, the site classification precision and the engineering applicability are improved.

The embodiment of the invention discloses an ultrasonic elastography method and ultrasonic imaging equipment. In the embodiment of the invention, ultrasonic imaging equipment can respectively obtain a first shear wave elasticity result and a first strain elasticity result of an external area of a focus in target tissue of a testee and obtain a second strain elasticity result of an internal area of the focus in the target tissue; a quantitative elasticity result for the internal region of the lesion is determined based on the first shear wave elasticity result, the first strain elasticity result, and the second strain elasticity result. The shear wave elasticity result and the strain elasticity result of the external region of the focus and the strain elasticity result of the internal region of the focus are accurate, so that the quantitative elasticity result of the internal region of the focus is calculated according to the results; compared with the method of directly measuring the shear wave elasticity of the internal area of the focus, the method has the advantages that the obtained result is more accurate, and the form and boundary of the focus can be presented more accurately.

The invention relates to the technical field of petroleum geophysical exploration, and particularly discloses a consolidation parameter optimization and soft pore volume ratio shear wave velocity prediction method and device, and the method comprises the steps: calculating the elastic modulus of a dry rock skeleton based on a dual-pore medium rock physical model; based on the elastic modulus of the dry rock skeleton, calculating the elastic modulus of the fluid saturated rock through a Gassmann equation, and further calculating and predicting the longitudinal wave velocity; by continuously adjusting input parameters and optimizing consolidation parameters and a soft hole volume ratio, the error between the predicted longitudinal wave speed and the measured longitudinal wave speed is minimized, and the optimized consolidation parameters and the optimized soft hole volume ratio are obtained; and calculating the shear wave velocity based on the optimized consolidation parameters and the soft pore volume ratio. According to the method, the influence of the pore structure and the diagenesis consolidation effect on the longitudinal and transverse wave velocity of the rock is fully considered, the method has definite physical meaning and geological significance and relatively high prediction precision, and the situation that most models only consider the diagenesis consolidation effect or focus on a single pore structure is avoided.

The invention discloses an ultrasonic shear wave elastography-based intrameniscus tearing quantitative evaluation method and system, and relates to the technical field of computer-aided diagnosis. The method is used for solving the problem of insufficient quantification of meniscus tearing detection. The method comprises the following steps: firstly, fixing a knee joint at a preset buckling angle, exciting shear waves along an annular fiber direction and a vertical direction, and collecting ultrasonic radio-frequency signals of an affected side meniscus and an uninjured side meniscus in different load states; then, a three-dimensional anisotropic elastic atlas is constructed based on the shear wave propagation velocity field, and spatial elastic distribution characteristics of the tissue are obtained; thirdly, calculating an elastic continuity index, a spatial variation coefficient and an abnormal region morphological parameter, and quantitatively representing the continuity and local tearing characteristics of the tissue structure; and finally, inputting the multi-dimensional features into a multi-branch neural network, fusing the features through a cross-branch attention mechanism, and outputting a meniscus tearing quantitative evaluation value, thereby realizing intelligent and objective evaluation of the tearing degree, and providing a basis for clinical diagnosis and postoperative rehabilitation.

The present application relates to the geological exploration technical field, more particularly, to a deep water super shallow layer natural gas reservoir rock physics shear wave velocity prediction method, comprising: calculating equivalent bulk modulus, shear modulus and density of a plurality of mineral mixed matrix according to shale content; then calculating skeleton bulk modulus and shear modulus; then calculating saturated rock bulk modulus and shear modulus through a model, and calculating saturated rock density through rock matrix density; distributing longitudinal and transverse velocities of suspended state and bearing state, and calculating equivalent longitudinal and transverse wave velocities; using equivalent longitudinal wave velocity to construct an inversion objective function with longitudinal wave velocity as a known condition; comparing actual longitudinal wave velocity with calculated longitudinal wave velocity; realizing nonlinear inversion of transverse wave velocity according to an algorithm, and obtaining transverse wave velocity of a to-be-inverted work area. The present application simultaneously considers rock physics models of particle suspended state and bearing state, and realizes transverse wave velocity prediction and deep water super shallow layer natural gas reservoir transverse wave velocity direct inversion.

For shear wave imaging with ultrasound, the apparent pulse repetition frequency is increased by combining displacements from different lateral locations. Different combinations based on different shear wave velocities and corresponding time shifts and / or attenuations and corresponding scalings are tested to find a smooth displacement profile for the combination. Once the smooth displacement profile is found, the corresponding shear wave velocity is estimated or determined.

An ultrasound imaging probe includes a backing layer, an acoustic stack with an interconnect coupled to the backing layer, a transducer array electrically coupled interconnect and including at least one transducer element with a transducing surface and at least one matching layer with a first side acoustically coupled to the transducing surface and a second opposing side, a compound lens including an inner lens with a planer inner side acoustically coupled to the second opposing side of the matching layer and a first non-flat side that is non-flat in elevation and wavy at least in azimuth and an outer lens with an outer side configured to contact a subject or object, and a second non-flat side that is non-flat in elevation and wavy at least in azimuth, wherein the first non-flat side of the inner lens is acoustically coupled to the second non-flat side of the outer lens.

The utility model discloses a semi-explosion type transverse wave source based on high-pressure gas explosion near-field waveform regulation and control, which comprises a cylindrical detonation tube, a gas chamber is arranged in the detonation tube, one side of the gas chamber is an arc-shaped surface, the central axis of the arc-shaped surface is consistent with that of the detonation tube, the other side of the gas chamber is an isolation surface, and the isolation surface is arranged on the detonation tube. A groove consistent with the detonation tube in the extending direction is formed in the side, close to the isolation face, of the tube wall of the detonation tube to form a waveform regulation and control chamber, an annular notch groove is formed in the side, close to the arc-shaped face, of the tube wall of the detonation tube, and sealing heads are arranged at the two ends of the detonation tube. The semi-explosive shear wave source realizes near-field waveform regulation and control on a high-pressure gas detonation pressure field through structural design, performs near-field waveform regulation and control on the pressure field generated by detonation through structural design of the detonation tube, enables the energy proportion of a generated shear wave signal to be amplified, is a brand-new shear wave source generation way, and can be applied to the field of high-pressure gas detonation. The system has the advantages of being strong in transverse wave signal, environmentally friendly, good in economical efficiency, good in field adaptability and the like.

The embodiment of the present application discloses an ultrasonic elastography method and an ultrasonic imaging device. In the embodiment of the present application, the ultrasonic imaging device can acquire a first shear wave elasticity result and a first strain elasticity result of an external region of a lesion in a target tissue of a subject, acquire a second strain elasticity result of an internal region of the lesion in the target tissue, and determine a quantitative elasticity result of the internal region of the lesion based on the first shear wave elasticity result, the first strain elasticity result and the second strain elasticity result. Since the shear wave elasticity result and the strain elasticity result of the external region of the lesion and the strain elasticity result of the internal region of the lesion are all accurate, the quantitative elasticity result of the internal region of the lesion calculated according to the above results is more accurate than the result obtained by directly performing shear wave elasticity measurement on the internal region of the lesion, and the morphology and boundary of the lesion can also be more accurately presented.

The application provides a formation fracturing detection method and device, a storage medium and a processor, and belongs to the technical field of well logging. The method obtains a frequency spectrum array of original array waveform data, calculates slowness values of each acoustic mode, then obtains a frequency dispersion curve greater than a preset resolution according to iterative operation of hierarchical clustering and threshold division, projects the time difference and the frequency of the frequency dispersion curve to a time difference axis by using a time difference-frequency projection method to obtain a time difference-frequency projection curve after fracturing, overlaps the time difference-frequency projection curve after fracturing with a time difference-frequency projection curve before fracturing to obtain a time difference change value at the lowest frequency, and finally determines the degree of formation fracturing according to the time difference change value at the lowest frequency to obtain a formation fracturing detection result, so that the change of formation shear wave velocity caused by fracturing and the degree of formation fracturing can be accurately distinguished.

Shear wave phase velocity is estimated from measurements of shear wave motion obtained using ultrasound shear wave elastography or other suitable elastography techniques. Shear wave dispersion curves are generated using a combined generalized Stockwell transform and slant wave number-frequency analysis. A modified version of the S-transform is used to control the time-frequency resolution of a time-frequency decomposition of a signal.