769 results about "Longitudinal wave" 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 relates to the technical field of pipe network data processing, in particular to an automatic monitoring data processing method for pipe network pressure. The method comprises the following steps: acquiring pipe network structure data; constructing a pipeline topology network based on the pipe network structure data to generate the pipeline topology network; screening main pipelines and branch pipes of the pipeline topology network to obtain pipe network circulation data; carrying out pipe wall microwave resonator deployment on the main pipeline and the branch pipelines based on the pipe network circulation data, and capturing pipeline circumferential deformation harmonic waves in real time through the deployed microwave resonators; longitudinal wave propagation time delay of pipe network circulation data is analyzed, and a pipe body structure dynamic resonance atlas is constructed in combination with pipeline circumferential deformation harmonic waves; and carrying out pipe network internal pressure and pipe wall equivalent stress calculation on the pipeline topology network through a pipe body structure dynamic resonance map. By combining pipeline topology analysis, microwave resonator monitoring, dynamic resonance spectrum and bidirectional fluid-solid coupling analysis, the accuracy of pipe network pressure monitoring and identification is improved.

The invention relates to the technical field of cast-in-place pile detection, and discloses a cast-in-place pile integrity detection system based on a multi-mode ultrasonic array, and the system comprises a deformable multi-mode ultrasonic probe which is used for adaptively adjusting the posture through an intelligent material driver; the intelligent coupling injection module is used for automatically cleaning the inner wall of an internal channel of the cast-in-place pile; the multi-source data processing module is used for receiving the original ultrasonic waveform data and the real-time position information of the ultrasonic probe; the deep learning recognition module is used for generating a recognition result including defect categories and preliminary features; the defect positioning and evaluating module is used for constructing a defect model comprising defect space coordinates, geometric dimensions and severity parameters; and the diagnosis decision module is used for providing targeted repair suggestions. The ultrasonic signals are transmitted and received through the integrated longitudinal wave transducer, the transverse wave transducer and the Rayleigh wave transducer, the internal structure information of the pile body is obtained, in this way, the ultrasonic beam coverage range is expanded, and the detection blind area of the area between the sounding pipes in a traditional method is effectively made up.

The invention relates to the technical field of hemispherical harmonic oscillator assembly, in particular to a welding method and device for an assembled hemispherical harmonic oscillator, and the device comprises a vibration welding platform and a clamping assembly located above the vibration welding platform; the vibration welding platform is used for bearing the sensitive base and providing a thermal field and a vibration field needed by welding, and the clamping assembly is used for clamping the center shaft and sending the center shaft into a center hole of the base. A heating unit and a composite vibration ultrasonic transducer are arranged in the platform, and the platform is configured to apply high-frequency vibration formed by superposition of vertical longitudinal waves and horizontal torsional waves to the base. The high-frequency vibration thixotropic effect is used for reducing the viscosity of the molten solder, the ultrasonic cavitation effect is used for forcibly discharging bubbles at the bottom of the blind hole, and the sound radiation pressure generated by the vibration standing wave field is used for driving the center shaft to achieve friction-free self-centering in the hole. According to the device, the problems of air bolt pseudo soldering and rigid assembly clamping stagnation in the traditional process are solved, and the assembly coaxiality and the connection strength of the harmonic oscillator are remarkably improved.

The invention discloses a multi-wave chromatography and reflection combined detection method and device for a thin-covering-layer urban active fault and a medium. The method comprises the steps that longitudinal wave seismic data and transverse wave seismic data are collected; recording vertical component data based on the longitudinal wave seismic data for first arrival travel time pickup and tomography inversion to obtain a longitudinal wave velocity structure model Vp; extracting Rayleigh surface wave frequency dispersion through the vertical component data and carrying out multichannel surface wave analysis inversion to obtain a transverse wave velocity structure model Vs; calculating a longitudinal and transverse wave velocity ratio parameter structure model Vp / Vs, and calculating to obtain a Poisson's ratio parameter structure model v; obtaining a longitudinal wave (P wave) reflection profile and a transverse wave (S wave) reflection profile; identifying and summarizing into an interpretation fracture set Fc, and recording key elements; and by taking the interpretation fracture set Fc as a structural skeleton, completing unified registration and superposition display on Vp, Vs, Vp / Vs and v, a longitudinal wave reflection profile and a transverse wave reflection profile, and outputting a shallow underground structure comprehensive interpretation map of the thin covering layer region.

The invention discloses a rock compressive strength prediction system and method based on grey correlation analysis and GWO-BILSTM, and the system is characterized in that a data collection unit is used for collecting Schmidt rebound index, Leeb hardness, Rockwell hardness, longitudinal wave velocity, density and uniaxial compressive strength measured values, and taking the above factors as original data; a gray correlation analysis module, a model optimization module and a compressive strength prediction module are arranged in the data processing unit, and the gray correlation analysis module is used for performing normalization processing on data and calculating a gray correlation degree; the model optimization module is used for optimizing the compressive strength prediction module; the compressive strength prediction module is used for predicting the compressive strength of the rock and outputting a result to the visual output module; the method comprises: collecting data; correlation degree analysis and input feature screening; establishing a rock compressive strength prediction model based on a bidirectional long-short-term memory network, and performing optimization by using a GWO algorithm; and carrying out actual prediction. The system and the method can realize efficient and accurate prediction of the compressive strength of the rock.

The invention relates to a near-surface longitudinal wave velocity modeling method and device based on micro-motion exploration, and the method comprises the steps: obtaining a surface survey-based ground geological map of a target work area, and correcting a geological boundary of the surface survey-based ground geological map; according to stratum, fault and stratum occurrence information provided by the corrected ground geological map, a geological cross section is drawn along a seismic survey line, and a shallow ground structure model of the target work area is obtained; obtaining the shallow surface shear wave velocity of each preset measuring point in the target work area, and converting the shallow surface shear wave velocity of each preset measuring point into a longitudinal wave velocity; with the shallow ground structure model as a constraint, spatial interpolation is carried out on the longitudinal wave velocity of each preset measuring point to obtain a near-surface longitudinal wave velocity model based on the shallow ground structure model and a shallow velocity field based on the shallow ground structure model, the inversion velocity is close to the stratum velocity, and the precision is high; and a good near-surface longitudinal wave velocity model is provided for subsequent pre-stack depth migration.

The invention provides a full-section detection method, device and equipment for reinforcing a steel rail welding seam and a storage medium, and relates to the technical field of nondestructive testing. The method comprises the following steps: respectively arranging a plurality of first phased array probes on rail head treads and rail bottom surfaces of a first steel rail and a second steel rail, and arranging a second phased array probe right above a welding seam; the detection method comprises the following steps: determining optimal parameters of a transducer based on the material of the steel rail, the size of the cross section of the steel rail and the sound pressure intensity at a preset focusing depth position; determining the optimal scanning angle range of the first phased array probe based on the propagation velocity of the ultrasonic longitudinal wave in the wedge block and the steel rail, the propagation velocity of the ultrasonic transverse wave in the steel rail and the Snell's law; and controlling the first phased array probe to carry out sector scanning imaging within the optimal scanning angle range, and controlling the second phased array probe to carry out zero-degree line scanning imaging, so as to detect the full section of the welding seam. According to the invention, the welding seam can be accurately detected without dismounting the clamping plate.

The invention relates to a regional fracturing influence range monitoring method based on distributed optical fiber sound wave sensing, and the method comprises the steps: pre-arranging a DAS monitoring system in a fracturing region, and collecting an original signal of the fracturing region through the DAS monitoring system; identifying the original signal, and obtaining a micro-seismic signal and first arrival time of a longitudinal wave in the micro-seismic signal; based on the first arrival time of longitudinal waves in the micro-seismic signals, the distribution position of micro-seismic events in the fracturing area is determined; according to the distribution position of the micro-seismic event in the fracturing area, the hydraulic fracturing influence range in the fracturing area is determined, the original signal of the fracturing area is collected through the DAS monitoring system, the distribution position of the micro-seismic event in the fracturing area is determined by processing the original signal, accurate characterization of the hydraulic fracturing crack propagation form is achieved, and the hydraulic fracturing influence range in the fracturing area is determined. The accuracy and efficiency of determining the effective influence range of hydraulic fracturing are improved, reference can be provided for optimization of a hydraulic fracturing scheme, the hydraulic fracturing pressure relief effect is improved, and the production safety of a coal mine is guaranteed.

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.

The invention relates to the technical field of unconventional shale oil and gas resource exploration, in particular to a shale shear wave velocity estimation method considering clay directional arrangement influence. According to the technical scheme, a shale compaction model is constructed, a shale directional arrangement background medium is formed, an orientation distribution function is used for simulating the elastic tensor of the background medium under different directional arrangement degrees, and the anisotropic speed of the background medium is calculated; calculating a longitudinal wave speed and a transverse wave speed in an equivalent isotropic background medium according to the anisotropic speed, and then calculating a bulk modulus and a shear modulus of the equivalent isotropic background medium; and adding clay-related pores and sand-related pores into an equivalent isotropic rock matrix by using an Xu-White model to obtain a bulk modulus and a shear modulus of dry shale, and finally simulating the shear wave velocity of the shale under the influence of directional arrangement of the clay. According to the invention, a new rock physical model is established to simulate the influence of clay directional arrangement, pore morphology, mineral and fluid properties on longitudinal and transverse wave velocities in shale.

The invention discloses a bolt axial force measurement method based on trailing waves and temperature compensation, and relates to the technical field of bolt axial force measurement. The influence of stress and temperature on the bolt length and ultrasonic sound velocity is analyzed, sound time variation of longitudinal waves and primary trailing waves under the action of stress and temperature is obtained, the longitudinal waves and the primary trailing waves are selected to serve as a wave type combination of bolt axial force measurement based on sensitivity analysis of sound waves on stress and temperature, and a sound elasticity principle is combined to measure the bolt axial force. Establishing a relation model of ultrasonic sound velocity, stress and temperature, and respectively calculating longitudinal wave sound time and primary trailing wave sound time considering the comprehensive influence of the stress and the temperature; and constructing a measurement characterization quantity of the bolt axial force based on longitudinal wave and primary trailing wave sound time, and performing temperature compensation on axial stress measurement to complete bolt axial force measurement. The axial force characterization quantity is constructed by measuring the sound time difference by utilizing the propagation information of the longitudinal wave and the primary trailing wave, and the axial force measurement requirement of the fastened bolt in the high-temperature environment is met.

The invention discloses an ultrasonic orthogonal scanning measurement method for mechanical properties of a fiber reinforced composite material. The method comprises the following steps: aiming at a composite material unidirectional plate to be detected, fixing receiving (transmitting) points on the surface of one side of a material, positioning the transmitting (receiving) points on the surface of the other side of the material, performing linear scanning along any two orthogonal directions, and recording transmission quasi longitudinal wave and quasi transverse wave time domain waveform signals which are acquired by combining each pair of transmitting and receiving points and are propagated along different paths; establishing an acoustic model for quantitatively describing the quantitative relationship between the ultrasonic trend and the independent elastic constant, thickness and fiber direction angle of the to-be-tested fiber reinforced resin matrix composite so as to simulate an ultrasonic data acquisition experiment and generate a corresponding simulated ultrasonic data set; and updating the independent elastic constant, the thickness and the fiber direction angle value of the composite material by taking the similarity degree between ultrasonic data sets obtained by experiments and simulation as a target function. According to the invention, multi-parameter high-precision in-situ nondestructive measurement of mechanical properties, thickness and fiber orientation of materials can be synchronously realized.

The invention relates to a buried hill reservoir permeability evaluation method and system based on Stoneley wave time difference intelligent prediction, processing equipment and a storage medium. The method comprises the following steps: preprocessing core physical property, conventional logging and electric imaging logging data in a target area; array acoustic logging data are processed, and longitudinal wave, transverse wave and stoneley wave time difference of each well in the target area is extracted; establishing an intelligent stoneley wave time difference prediction model, and predicting the stoneley wave time difference of the interval with poor stoneley wave data quality of each well; determining the effective fracture development position and the fracture width of each well; carrying out a crack plate model experiment, and calculating the total permeability of the stratum at the effective crack development position according to the effective crack development position and the crack width of each well; inverting the total permeability of the buried hill reservoir; on the basis of the plunger sample core permeability and the total stratum permeability calculated at the effective fracture development position, permeability inversion results of the effective fracture non-development position and the effective fracture development position of each well are calibrated, and the method can be widely applied to the field of oil and gas exploration and development.

The invention belongs to the technical field of seismic exploration, and particularly discloses an elastic wave vector seismic exploration data static correction method, which comprises the following steps: S1, establishing a longitudinal wave micro-logging surface velocity model; s2, establishing a three-component micro-logging shear wave surface velocity model; s3, performing low-frequency static correction on the longitudinal wave seismic data; s4, performing low-frequency static correction on the transverse wave seismic data; s5, performing low-frequency static correction on the converted wave seismic data; s6, calculating residual static correction values of shot points and detection points of the longitudinal wave field, the converted wave field and the transverse wave field; and S7, calculating total static correction values of shot points and detection points of the longitudinal wave field, the converted wave field and the transverse wave field. According to the method, the static correction problem of various wave field seismic data in elastic wave vector seismic exploration is effectively solved, and the calculation efficiency and the imaging precision are improved. The method is suitable for static correction of seismic exploration data.

The invention relates to the technical field of geological exploration, in particular to a deep water ultra-shallow natural gas reservoir rock physical shear wave velocity prediction method, which comprises the following steps: calculating the equivalent bulk modulus, shear modulus and density of a mixed matrix of various minerals according to the shale content; calculating the bulk modulus and the shear modulus of the skeleton; calculating the bulk modulus and the shear modulus of the saturated rock through the model, and calculating the density of the saturated rock through the density of the rock matrix; distributing longitudinal and transverse velocities in a suspension state and a bearing state, and calculating equivalent longitudinal and transverse wave velocities; taking the longitudinal wave velocity as a known condition, and constructing an inversion objective function by using the equivalent longitudinal wave velocity; comparing the actual longitudinal wave speed with the calculated longitudinal wave speed; and realizing nonlinear inversion of the shear wave velocity according to an algorithm, and obtaining the shear wave velocity of the work area to be inverted. According to the method, rock physical models in a particle suspension state and a bearing state are considered at the same time, and shear wave velocity prediction and direct inversion of the shear wave velocity of the deepwater ultra-shallow natural gas reservoir are realized.

The invention discloses a rock mass integrity index Kv determination method under a high crustal stress condition, and relates to the technical field of rock mass basic quality evaluation, and the method comprises the following steps: carrying out field crustal stress test to obtain the crustal stress of a rock mass and the elastic longitudinal wave velocity of the rock mass; if the result of the field crustal stress test is judged to be extremely high crustal stress or high crustal stress, determining a rock mass integrity index Kv according to the following method; a high-pressure rock triaxial dynamic test system is used for carrying out a standard cylinder sample wave velocity stress test for recovering the confining pressure of an original ground stress environment, and the elastic longitudinal wave velocity of the standard cylinder sample considering the confining pressure is obtained. The rock mass integrity index Kv is calculated based on the longitudinal wave velocity of the rock mass and the elastic longitudinal wave velocity of the standard cylinder sample, the rock core unloading effect caused by high ground stress is considered, the actual integrity of the rock mass is accurately reflected, and the problem that the Kv value is too high in a traditional method is solved. By more accurately calculating the Kv value, the rock mass quality is more scientifically evaluated, and a more reliable basis is provided for engineering design and construction.

The invention discloses a seismic data acquisition device based on a ground 3C-DAS optical cable and an acquisition method thereof, is applied to the field of seismic exploration, and aims to solve the problems of high layout cost, too long construction time and low operation efficiency of an existing ground three-component detector. According to the method, a 3C-DAS armored optical cable is buried under a shallow earth surface in a parallel or orthogonal mode, a ground multichannel low-frequency DAS modulation-demodulation instrument collects phase data of Rayleigh scattering light reflected back from the 3C-DAS armored optical cable and carries out modulation-demodulation processing, and high-density distributed three-component seismic data distributed along the 3C-DAS armored optical cable is obtained; according to the system, high-density distributed three-component ground seismic data along the armored optical cable can be rapidly and efficiently acquired at low cost; the invention also provides a processing method for the collected high-density distributed three-component ground seismic data, an analysis method for a shallow surface velocity structure with high spatial resolution, and an inversion imaging method for longitudinal waves, transverse waves and surface waves.

The invention discloses a wind power high-strength bolt axial stress detection method based on a GA-BP neural network, and the method comprises the following steps: 1, selecting high-strength bolts with different isopolarities and lengths, and obtaining an ultrasonic transverse and longitudinal wave sound-time ratio and loading stress data; 2, establishing a BP neural network structure between the ultrasonic transverse and longitudinal sound time ratio and the three parameters; 3, randomly distributing the original data to different groups; 4, optimizing the BP neural network model through a GA (Genetic Algorithm); 5, forming a GA-BP neural network model; and 6, substituting GA-BP neural network data into a bolt axial stress formula to obtain the axial stress of the high-strength bolt. According to the detection method, a GA-BP neural network is established to accurately predict the three parameters of the bolt and the ultrasonic transverse and longitudinal wave sound-time ratio, the accurate numerical value of the axial stress of the bolt is obtained through calculation, and then the accurate numerical value is compared with the axial stress obtained by actually measuring the ultrasonic transverse and longitudinal wave sound-time ratio, so that whether the high-strength bolt fails or not is judged. And safety accidents are avoided.

The invention provides a method and a device for determining a fracture fluid indication factor of a deep coal bed gas reservoir, and relates to the technical field of deep coal bed gas exploration. The method comprises the following steps: firstly, constructing a deep coal bed gas reservoir approximate PP wave reflection coefficient equation directly expressed by six reservoir parameters including wave impedance, longitudinal wave velocity, shear modulus, anisotropic parameters, fracture fluid indication factors and fracture tangential weakness; then, a target functional used for inverting reservoir parameters of the deep coalbed methane reservoir is constructed in combination with synthetic azimuth gather seismic data of the deep coalbed methane reservoir of the target work area, and finally, the fracture fluid indication factor of the deep coalbed methane reservoir can be directly inverted by solving the target functional. According to the method, the problem of error accumulation existing in indirect inversion of the fracture fluid indicator factor is avoided, so that the technical problem of poor inversion result accuracy existing in an existing determination method of the fracture fluid indicator factor of the deep coal bed gas reservoir can be effectively relieved.

The embodiment of the invention provides a simple system for simulating fluctuating motion of ocean conditions, and relates to the field of ocean-related simulation experiments. The device comprises a base, a translation seat, a stand column, a top beam, a lifting seat, a simulation water tank and a transverse vibration mechanism, the translation seat is installed on the base, the stand column is installed on the translation seat, the top beam is installed at the top end of the stand column, the lifting seat is installed on the stand column in a sliding mode, and the simulation water tank is installed on the lifting seat; the translation seat is mounted on the base through a transverse vibration mechanism, and the transverse vibration mechanism can enable the translation seat to do transverse reciprocating motion. Transverse waves can be generated, and corresponding wave fluctuation can be simulated; meanwhile, longitudinal waves can be generated, so that wave fluctuation generated by the longitudinal waves is simulated; the equipment has the two capabilities at the same time, can be selected according to requirements, and is high in universality. In addition, the device can enable the liquid to quickly recover calm, facilitates the switching of different seismic source modes for simulation testing, and improves the efficiency.

The invention discloses a multi-scale fractured porous medium rock physical modeling method and device. The method comprises the following steps: determining an elastic modulus of an equivalent rock containing pores and microscopic cracks by utilizing an equivalent medium model based on respective elastic moduli and geometric factors of a mineral matrix, the pores and the microscopic cracks; on the basis of the elastic modulus of the equivalent rock containing the pores and the microscopic cracks, determining the elastic modulus of the equivalent rock containing the extrusion jet effect of the microscopic cracks; based on the elastic modulus of the equivalent rock containing the microcosmic fracture extrusion jet flow effect, the far-field scattering amplitude caused by each group of mesoscopic fractures is determined, the total far-field scattering amplitude caused by all the mesoscopic fractures is obtained, and the total effective longitudinal wave number is determined; and according to the total effective longitudinal wave number, establishing a multi-scale fractured porous medium rock frequency dispersion and attenuation model. According to the method, the frequency dispersion and attenuation model comprehensively considering the crack scale effect and the frequency dispersion characteristic can be established.

The invention provides an earthquake quantitative prediction method for the compaction effect intensity of carbonate rocks, and the method comprises the following steps: (1) carrying out the statistics and analysis of logging data and core analysis data of a compacted stratum in a to-be-analyzed region, and building a fitting relation between the apparent compaction rate and the longitudinal wave speed; (2) performing phase-control frequency-division inversion in combination with the seismic response characteristics, and then calculating and analyzing the actual longitudinal wave speed of the to-be-analyzed region; and (3) determining the distribution of the apparent compaction rate according to the fitting relation between the apparent compaction rate and the longitudinal wave speed obtained in the step (1) and the actual longitudinal wave speed obtained in the step (2). According to the carbonate rock diagenesis strength earthquake prediction method based on the apparent compaction rate, the problem that quantitative prediction of the carbonate rock compaction strength is difficult is solved, the distribution characteristics of different compaction strength in space are defined, and the exploration and development success rate can be improved.

The invention relates to the technical field of industrial detection, in particular to an electromagnetic ultrasonic double-wave transducer for detecting residual stress of a pipeline. The problems that in the prior art, single-wave detection errors are large, the fitting degree of a sensor and a pipeline curved surface is poor, and impact force affects an internal structure are solved. The invention provides an electromagnetic ultrasonic double-wave transducer. The electromagnetic ultrasonic double-wave transducer comprises a shell, a magnet assembly, a coil and other components. The magnet assembly is composed of a transversely-arranged first magnet, a longitudinally-symmetrical second magnet and a longitudinally-symmetrical third magnet, the included angle between the magnets is adjusted through a hinge, and vertical and horizontal magnetic fields are formed to excite transverse waves and longitudinal waves at the same time. The lower portion of the shell is arc-shaped and attached to the curved surface of the pipeline, and an elastic supporting structure and a flexible buffering layer are arranged at the joint to buffer impact force. In addition, a grounding lead is arranged to improve the signal-to-noise ratio. Through multi-magnet combination, the arc-shaped shell and the grounding wire buffer design, the magnetic field uniformity and the detection signal strength are effectively improved, and transverse and longitudinal wave integrated high-precision residual stress detection is realized.

The invention relates to the field of petroleum engineering, and discloses a pore pressure determination method and device, a storage medium and electronic equipment. The method comprises the following steps: determining longitudinal wave time difference and transverse wave time difference of a rock debris sample, respectively performing overburden pressure correction on the longitudinal wave time difference and the transverse wave time difference, and determining a longitudinal wave and transverse wave ratio according to the corrected longitudinal wave time difference and transverse wave time difference; determining the content of each mineral in the rock debris sample and reconstructing the density content and the shale content; according to the density content, the shale content, the longitudinal wave time difference and the transverse wave time difference, the conversion relation between the dynamic and static elastic parameters is determined; determining vertical principal stress according to the density content; determining a relation between a longitudinal-transverse wave ratio and effective stress according to a conversion relation between the dynamic and static elastic parameters and preset static pressure test data; and determining a pore pressure determination model according to the vertical principal stress and the relation between the ratio of the longitudinal wave to the transverse wave and the effective stress. The invention discloses a while-drilling real-time pressure prediction method, and the real-time monitoring effect of the formation pressure is improved.

The invention discloses a method and device for measuring the center frequency of an ultrasonic longitudinal wave probe, and belongs to the technical field of ultrasonic detection. The method comprises the specific steps that an isotropic metal test block containing a specific flat-bottomed hole and a transverse through hole is manufactured, and the flat-bottomed hole and the transverse through hole are both located in a probe far-field region; by measuring the echo height (Hf) and time (tf) of a flat-bottom hole and the echo height (Hs) of a transverse through hole and combining the positions and sizes of the flat-bottom hole and the transverse through hole, the center frequency (f) of the probe is calculated based on a formula. According to the method, the sound field characteristic difference of the double reflectors is creatively used for counteracting the machining precision interference, the operation process is simplified, and the problems that a traditional method is high in equipment cost, complex in operation and limited in applicability are solved. The test block also supports multi-material adaptation (steel, aluminum, titanium alloy and the like) and is suitable for industrial sites and laboratory environments, and the detection efficiency and economical efficiency are remarkably improved.

The utility model relates to the technical field of anti-seismic inspection, and discloses a frame anti-seismic inspection bench for constructional engineering design, which comprises a base plate, an installation shell is fixedly installed at the top of the base plate, and a fluctuation assembly for carrying out seismic longitudinal wave anti-seismic inspection is arranged on the installation shell. And the fluctuation assembly comprises a fixed shaft, a movable shaft, a motor, an eccentric wheel and a fluctuation rod, the fixed shaft is fixedly installed between the opposite sides of the inner side walls of the installation shell, and the movable shaft is rotationally connected between the opposite sides of the inner side walls of the installation shell. According to the frame anti-seismic inspection bench for constructional engineering design, the fluctuation assembly is arranged, after the fluctuation assembly is used, the movable shaft drives the eccentric wheels in different directions to rotate, the fluctuation rod is driven by the eccentric wheels to swing back and forth along the axis of the fixed shaft, and due to the eccentric wheels in different directions, the fluctuation rod swings up and down differently, and crests and troughs can be formed; therefore, a form similar to a seismic longitudinal wave is formed, and the longitudinal wave anti-seismic test of the frame is realized.

The embodiment of the specification discloses a self-adaptive variable grid forward modeling method for middle-deep dry hot rock mass. p , a transverse wave velocity V s and a medium density p model, pre-setting forward modeling parameters; performing self-adaptive variable grid processing on the velocity model, determining a mapping relationship between coordinate systems, and determining a wave equation under variable grid based on the mapping relationship; performing self-adaptive variable grid processing on the velocity model, determining a mapping relationship between coordinate systems, obtaining the underground medium longitudinal wave velocity, transverse wave velocity and density after variable grid, determining a wave equation under variable grid based on the mapping relationship, and generating final regular grid horizontal direction longitudinal wave field, horizontal direction transverse wave field, vertical direction longitudinal wave field and vertical direction transverse wave field information by using the mapping relationship reversely according to the wave field information in each direction at a specific moment after the variable grid, so that the memory occupation is small and the calculation speed is faster.

The invention relates to the technical field of stress detection, in particular to an acoustic nondestructive testing method and system for bolt tightness, and the method comprises the following steps: transmitting longitudinal waves and transverse waves to a bolt without pretightening force, and calculating the propagation time ratio M of the longitudinal waves and the transverse waves in the bolt without pretightening force under the environment temperature change condition; transmitting longitudinal waves and transverse waves to the bolt with the pre-tightening force, and calculating the propagation time TP and TS of the longitudinal waves and the transverse waves in the bolt with the pre-tightening force under the environment temperature change condition; and calculating the stress sigma of the bolt according to the propagation time ratio M of the longitudinal wave and the transverse wave in the bolt without the pre-tightening force, the propagation time TP and TS of the longitudinal wave and the transverse wave in the bolt with the pre-tightening force and the effective clamping distance of the bolt under the environment temperature change condition. According to the invention, signal interference caused by temperature change and processing errors can be overcome, and the detection precision of the bolt stress is obviously improved.