76 results about "Laplace transform" patented technology

A method for locating a high-impedance ground fault of a smart distribution network with topology change adaptation includes: acquiring a fault traveling wave sample within a specified time window after a fault occurs, and performing continuous wavelet transform on the fault traveling wave sample to obtain traveling wave full waveform feature information; establishing a graph structure of a power distribution network, obtaining a corresponding adjacency matrix, and obtaining node position and structure encoding information in the graph structure through graph random walk and graph Laplace transform; concatenating the node position, the structure encoding information and the traveling wave full waveform feature information to obtain a node feature, and inputting the node feature and an edge feature into the graph structure to establish a graph sample data set; constructing and training a Graph Transformer model; and calling the trained Graph Transformer model to locate a fault in to-be-detected sample data.

The invention provides a lithium battery parameter online identification method based on dynamic weight particle swarm optimization, and relates to the field of power lithium battery model parameter identification. According to the method, a lithium battery equivalent circuit model based on a second-order RC network is established, and a state-space equation is derived according to the Kirchhoff's current law and the voltage law; a discrete output model is obtained through Laplace transformation and discretization processing; constructing a recursive least square parameter updater with a forgetting factor, and jointly optimizing an initial parameter vector of the forgetting factor recursive least square and the forgetting factor by adopting a dynamic weight particle swarm optimization algorithm; and based on the optimized initial parameter vector and the forgetting factor, performing recursive least square updating with the forgetting factor, performing online identification on model parameters, and reversely deducing an equivalent parameter value in an original circuit. According to the method, the parameter identification precision can be remarkably improved, and the problem that data saturation parameter convergence is slow in a traditional recursive least square method is solved.

The invention discloses a Laplace transformation-based steady-state boundary driven solute transport model solution and parameter calculation method, which comprises the following steps of: establishing a one-dimensional finite-scale underground water solute transport mathematical model on the basis of an underground water solute transport system; solving the mathematical model by combining groundwater dynamics, a convection-dispersion equation and a Laplacian transformation method, deducing a convection-dispersion test theoretical model under the condition of different Peclet numbers, and obtaining a standard curve for determining a medium permeability coefficient and a hydrodynamic dispersion parameter under the condition of different Peclet numbers; and carrying out a convection-dispersion test, and determining permeability coefficients and hydrodynamic dispersion parameters of the medium under different Peclet numbers by adopting a wiring method. The method has a rigorous mathematical model and strict mathematical theory derivation, perfects related theories and methods for determining the medium permeability coefficient and the hydrodynamic dispersion parameter in the convection-dispersion test under different Peclet numbers, and solves the technical problems existing in application of the convection-dispersion test in a one-dimensional finite scale model.

The invention relates to an IGBT module junction temperature estimation method and system, and the method comprises the following steps: obtaining a performance curve set of an IGBT module under different working conditions, and carrying out the fitting optimization, and obtaining an optimal performance curve set; constructing a transient thermal resistance curve model according to a transient thermal resistance principle, and constructing a second-order Foster thermal network model based on the transient thermal resistance curve model; performing Laplace transformation and discretization processing based on a backward difference method on the second-order Foster thermal network model to obtain a junction temperature estimation model; collecting a phase current instantaneous value, and calculating the total power loss of the IGBT module in real time in combination with the optimal performance curve set; and finally, the junction temperature of the IGBT module is obtained in real time by using the total power loss of the IGBT module obtained through real-time calculation and the junction temperature estimation model, and junction temperature estimation is completed. According to the method, the effect of improving the power loss precision of the IGBT module is achieved by optimizing the performance curve, and then the junction temperature estimation precision is improved.

The invention discloses a shale airflow seepage simulation method, device and equipment and a storage medium. The method comprises the steps that a seepage model of fluid flowing of a target horizontal well is obtained, the seepage model is dimensionless according to predefined dimensionless variables, and a dimensionless seepage model is obtained; determining a complex frequency domain seepage model based on Laplace transformation according to the dimensionless seepage model; determining shale gas yield data according to the complex frequency domain seepage model; and according to the shale gas yield data, determining a shale gas flow seepage simulation result. According to the technical scheme, the problem that the yield prediction accuracy of the multi-section fractured horizontal well of the shale gas reservoir is low is solved, an accurate mathematical model can be used for simulating the heterogeneity characteristics of a hydraulic fracture and a transformation area, accurate description of the shale gas seepage process is achieved, and then accurate and efficient prediction of the yield of the multi-section fractured horizontal well of the shale gas reservoir is achieved.

The invention provides a calculation method and system for a two-dimensional foundation pit unsteady-state seepage field under suspension type retaining wall supporting, and belongs to the technical field of computer aided design. Dividing a seepage field around the foundation pit into three regular areas according to the boundary condition when the boundary state is zero when seepage does not occur; sequentially carrying out Laplace transformation, Fourier transformation and inverse transformation on the time variables in the unsteady-state seepage equilibrium equation and the boundary condition of each region to obtain an expression of a water head series solution of a water head of each region; constructing a non-homogeneous equation set by utilizing continuous conditions among the regions; programming solving is carried out by utilizing orthogonality of a trigonometric function, and obtained constant terms are substituted into expressions of water head series solutions of all the areas; and carrying out inverse transformation on the solved expression by adopting a Stehfest method to obtain an expression of the unsteady-state seepage field water head solution of the foundation pit. The seepage field analytic solution calculated by the method has high precision, and the dynamic change characteristic of the seepage field around the foundation pit along with time can be accurately determined.

This invention relates to the field of wind tunnel aerodynamic measurement technology for hypersonic vehicles, and discloses a method for evaluating and optimizing the dynamic load testing accuracy of a wind tunnel force measurement system. The evaluation method involves: equating the force measurement system to a multi-degree-of-freedom spring and mass model; constructing a dynamic differential equation and performing a Laplace transform; then, combining the dynamic stiffness matrix to construct a frequency response function matrix; defining the output of the force measurement channel of a rod-type strain balance and solving for the transfer function from the excitation point to the force measurement channel; combining the reference transfer function and the actual load, calculating the identified load and performing a Fourier transform to obtain the relative identification error of the force measurement system at the excitation point; finally, calculating the power spectrum weighted average identification error at the excitation point and comparing it with the engineering allowable error to determine whether the system has undergone stiffness optimization. This invention not only accurately identifies the dynamic load of the force measurement system but also achieves stiffness optimization, improving the accuracy of unsteady aerodynamic force measurement.

The invention discloses a wave power generation and energy storage method based on a superconducting cable and an optimization controller. The method comprises the following steps: firstly, acquiring deviation between wave power generation power and power grid demand, and inputting the deviation to a TID controller after Laplace transformation; the core of the method is that an ant colony optimization algorithm is adopted to dynamically optimize a tilt term coefficient, an integral term coefficient and a differential term coefficient of a TID controller, a parameter space is discretized into candidate nodes, an ant colony probability optimization and pheromone updating mechanism is simulated, time weighted absolute error integral is taken as a fitness function, and an optimal control parameter combination is iteratively searched; based on the optimization result, the TID controller generates a master control signal, and after inverse transformation and physical constraint, the superconducting cable energy storage system is driven to rapidly charge and discharge, so that high-precision and self-adaptive stabilization of wave energy power fluctuation is realized. Intelligent parameter optimization and superconducting energy storage are combined, and the control performance, the response speed and the overall energy efficiency of the system are remarkably improved.

The present application relates to the technical field of intelligent travel planning, specifically a multi-modal data-driven multi-destination travel planning system, which comprises a data integration and analysis module, a time series conversion module, a time window calculation module, a strategy development module, a route optimization module, and a real-time adjustment module. In the present application, by integrating GPS tracking, social media, and online travel platform data, the accuracy of capturing traveler preferences and associated locations during travel is significantly improved. The dynamic connectivity analysis between travel paths and locations is optimized. The application of Laplace transform processing time series data simplifies complexity, improves conversion accuracy and response speed. The dynamic adjustment of time windows matches travel demand, optimizes stay time allocation, improves travel efficiency, continuously updates travel plans and dynamically adjusts routes, responds to emergencies, and improves the flexibility and practicality of travel arrangements, thereby significantly improving user satisfaction and travel experience quality.

The application discloses a kind of flexible direct current transmission line fault transient electrical quantity determination methods, comprising: according to the circuit parameter of MMC converter station, construct MMC equivalent circuit when inter-pole short circuit;According to the transmission line parameter obtained, establish the equivalent model of two-port of direct current transmission line under complex frequency domain;According to the equivalent circuit of MMC when inter-pole short circuit and the equivalent model of two-port of direct current transmission line, obtain the expression of direct current fault transient under complex frequency domain;The expression of direct current fault transient under complex frequency domain is carried out Laplace transformation to obtain time domain response, the whole trend of transient process after fault can be given more accurately by the application.The calculation process is simple, avoids the complicated modeling simulation process in traditional simulation method.Meanwhile, it can well reflect the occurrence wave process when overhead line fails.The method can accurately express the overall development trend of the fault current flowing through the protection installation before the converter station is locked after the fault occurs, and has a positive significance for the fault current suppression and protection setting design of MMC-HVDC system.

The application relates to a finite element numerical implementation method of an asphalt mixture fractional viscoelastic model, and belongs to the field of constitutive behaviors of asphalt mixtures. The application aims at the problem that the existing finite element method of the fractional viscoelastic model cannot consider both the calculation efficiency and the accuracy. The application comprises the following steps: obtaining a complex frequency domain modulus expression of the fractional viscoelastic model based on Laplace transformation; constructing a one-dimensional form of a stress-strain minimum-order differential expression of the asphalt mixture fractional viscoelastic model through time domain / complex frequency domain equivalent substitution; constructing a discrete form of a stress updating expression of the asphalt mixture fractional viscoelastic model based on non-classical method discrete fractional derivative terms in the stress-strain differential form; constructing a three-dimensional form of stress updating expressions and Jacobian matrix updating expressions of the fractional viscoelastic model based on common / abnormal Poisson ratio assumptions and an incremental iteration method; and writing a user subroutine UMAT for finite element numerical calculation. The application is used for finite element numerical implementation of the fractional viscoelastic model.

The invention provides a Laplace-DLTS defect parameter extraction method and a Laplace-DLTS defect parameter extraction system. The Laplace-DLTS defect parameter extraction method comprises the following steps: acquiring capacitance transient data obtained by a deep energy level transient spectrum test; carrying out preprocessing on the capacitance transient data; constructing a Laplacian transformation kernel function according to the capacitance transient data, and performing discretization processing to obtain a discrete Laplacian transformation model; regularization constraint parameters are introduced to construct a target function, a corresponding emissivity spectrum is obtained through numerical solution, and the regularization constraint parameters are adaptively determined according to signal characteristics of capacitance transient data; performing automatic peak identification on the emissivity spectrum based on a preset criterion; and according to the identified effective defect peak, automatically extracting and outputting physical parameters of the corresponding defect. By introducing the adaptive regularization constraint parameter, the regularization degree can be dynamically adjusted according to the actual signal characteristics of the capacitance transient data, the instability problem of noise amplification and solution is effectively suppressed, and the resolution capability and reliability of the emissivity spectrum analysis result are improved.

The invention discloses a color image blind watermarking method based on two-dimensional quantization index modulation, and the method comprises the steps: firstly carrying out the discrete Fourier transform of image blocks, and converting a pixel matrix into a frequency domain coefficient matrix; then, energy distribution is further optimized through Laplacian transformation, so that energy is obviously gathered in a left diagonal region and a right diagonal region of the matrix, and two maximum energy coefficients are obtained; on the basis, a two-dimensional quantization index modulation technology is innovatively utilized, and the robustness of a watermark algorithm is enhanced by optimizing a quantization strategy. The method not only has better invisibility, but also has better robustness, solves the problems of poor robustness and low invisibility of a color image digital watermarking algorithm, and is suitable for occasions of digital media copyright protection with strong robustness and high invisibility.

The invention discloses a deflection calculation method of a steel-concrete composite beam under uniformly distributed loads, and relates to the technical field of high-speed railway bridge construction. The method comprises the following steps: establishing a differential equation of the continuous steel-concrete composite beam and carrying out Laplace transformation to obtain an expression of a non-zero real solution; inverse transformation is carried out on the equation obtained after Laplace transformation, an analytical expression of the deflection of the composite beam is obtained, and the expression comprises a plurality of unknown quantities. Substituting the structure parameters and the material parameters of the composite beam into the non-zero real number solution expression to solve Laplace transformation parameters; the parameters and the boundary conditions are substituted into the deflection analytical expression, and matrix elements used for solving unknown quantities are obtained; and constructing a linear equation set, solving an unknown quantity, substituting the unknown quantity into a deflection analytical expression, and finally obtaining a complete expression for solving the deflection of the continuous composite beam. The complete expression of the deflection of the continuous composite beam provided by the invention is suitable for analyzing the deflection of a single-span or continuous steel-concrete composite beam, and has relatively high calculation precision.

The invention relates to the technical field of control and protection of a new energy power system, in particular to a short-circuit impact current calculation method, system and device for a network-forming converter and a medium, and the method comprises the steps: building a complete electromagnetic transient model of the network-forming converter, the electromagnetic transient model comprising a voltage loop, a current loop and an equivalent circuit of an LC filter; reducing the order of the electromagnetic transient model by adopting a dominant pole theory to obtain a second-order reduced-order model which retains the interaction characteristics of the control parameters and the passive device; deriving a d / q-axis current response analytic formula when the voltage of the power grid changes suddenly based on Laplacian transformation, separating transient current of d-axis and q-axis components, and calculating peak current and attenuation index of fault inrush current; and analyzing the quantitative relation of the proportional gain and the integral gain of the voltage loop to the attenuation index, and optimally configuring the proportional gain and the integral gain to suppress the inrush current oscillation, thereby solving the problem that the traditional method cannot quantitatively analyze the influence of the control parameters, and remarkably improving the transient stability of the system.

This application discloses a method, system, and electronic device for identifying joint model parameters of a collaborative robot. The method includes: equating the components of a collaborative robot joint to a dual-inertia elastic model and establishing dynamic equations; performing a Laplace transform on the dynamic equations to obtain the transfer function of the dual-inertia elastic model; constructing a control block diagram of the dual-inertia elastic model based on the transfer function; obtaining the transfer functions between electromagnetic torque and motor angular velocity and load angular velocity based on the control block diagram; obtaining the parameters to be identified based on the transfer function between electromagnetic torque and load angular velocity; dividing the transfer function between electromagnetic torque and motor angular velocity into three parts based on the frequency domain characteristics of the transfer function; and identifying the parameters of the model based on these three parts. The parameters obtained by the method of this application have clear physical meanings and high accuracy.

The present application relates to a kind of methods for calculating cell picture definition value based on saturation value, provide a kind of methods for calculating cell picture definition value based on saturation value, comprising the following steps: (1) the color conversion of cell picture obtained by shooting is carried out, and cell picture is converted from RGB (red green blue) channel to HSV (color, saturation, brightness);(2) separate out saturation channel picture S, remove part of noise by Gaussian filtering (or mean filtering), obtain picture S1;(3) select suitable size kernel to picture S1 and carry out Laplace transform and calculate absolute value, find out the position of change in picture, obtain picture S2;(4) set appropriate threshold, carry out thresholding processing to picture S2, record saturation value, find out corresponding bright spot position;(5) the bright spot position of multiple cell pictures is counted, and the saturation value of corresponding picture S2 is recorded.This algorithm is simple, effective, combined with Gaussian filtering (or mean filtering), Laplace transform, decision tree, morphological operation etc., so that the result of judging cell picture definition value is more accurate.

The application discloses a kind of 3D shape segmentation method and system based on text driving and attention mechanism, it is related to computer vision technical field, including: obtaining the 3D model to be handled and its corresponding component description text;Based on component description text input to prefix tuning module, obtain global sentence feature and multiple lexical features;Based on 3D model input to grid attention module, obtain multiple patch geometry features;Based on global sentence feature, lexical feature and patch geometry feature input to text-driven fusion module, obtain geometric text fusion feature;Based on geometric text fusion feature input to Laplacian adaptive attention module, obtain Laplace transform feature;Based on Laplace transform feature input to output module, obtain the predicted semantic label of each patch of 3D model, realize 3D model segmentation. Improve the segmentation accuracy of 3D shape.

This invention discloses a dimension-reduction reliability assessment method for switched reluctance motors (SRMs) that considers repairability. This method analyzes the faults of the SRM at structural levels, comprehensively converting the failure probabilities of each underlying component into overall system state transition parameters. Based on this, the repairability rate is calculated according to the actual periodic maintenance cycle of the equipment, and a Markov state transition equation system containing maintenance recovery paths is established. To avoid complex calculus operations involving high-order matrices, this invention utilizes Laplace transform to convert the dynamic process into algebraic calculations in the complex frequency domain, achieving analytical order reduction of the model. By performing algebraic analysis on the complex frequency domain function, the dynamic reliability function and mean time between failures (MTBF) of the system are directly obtained. This invention overcomes the shortcomings of traditional models, such as cumbersome computation and unrealistic lifespan predictions. While effectively reducing the computational complexity of microcontrollers, it significantly improves the accuracy of lifespan prediction for motor drive systems and enhances their engineering application value.

The application discloses a preset time formation control method for input delay multi-universal mobile robots, and belongs to the field of adaptive control of universal mobile robots. The control method comprises the following steps: establishing a dynamic model of multi-universal mobile robots with input delay, unknown nonlinear terms and external disturbance; introducing auxiliary vectors based on Padé approximation and Laplace transformation to simplify input delay analysis, and reconstructing the dynamic model based on the auxiliary variables; combining dynamic surface control technology to construct a preset time filter; step-by-step constructing Lyapunov functions to obtain an adaptive law and a preset time formation controller, wherein the preset time formation controller is used to output a control vector, the control vector is input into the reconstructed dynamic model, and formation control is realized. The preset time formation control method effectively suppresses the influence of input delay on the dynamic characteristics of the system, ensures the real-time performance of the control signal, and also ensures that each robot completes the formation task within the preset time.

This invention provides a method and apparatus for simulating electromagnetic signals in complex multi-regional natural environments. The method includes: acquiring characteristic parameters of the complex multi-regional natural environment; performing spatial discretization and numerical calculation using the DGTD and PE methods to obtain electromagnetic interference propagation characteristic data for each region; obtaining the transfer function of different regions using the Discrete Laplace Transform; cascading the transfer functions of each region to obtain the transfer function of the entire electromagnetic interference propagation region; using a LabVIEW program to mix the original electromagnetic signals and characteristic parameters of the entire electromagnetic interference propagation region to obtain an output signal; and using an NI and a radial hardware-in-the-loop simulation device to simulate the output signal to obtain the simulated electromagnetic signals of the complex multi-regional natural environment. The electromagnetic signal simulation method established by this invention for complex natural environments can accurately simulate the real electromagnetic environment of the field, solving the problem of indoor simulation equivalently replacing field tests in environments with complex structural obstacles.

The present application relates to the technical field of unmanned aerial vehicle network system modeling, and particularly relates to a method, system and software product for analyzing the accuracy of a phase point trajectory model of an unmanned aerial vehicle network system. The method constructs a three-layer seven-node equilateral triangle topology model with an analytical solution, sets node following rules using a unified PI controller, derives analytical expressions for the time-domain trajectories of each node through Laplace transformation, and compares the errors with the results of multi-step numerical simulation to calculate the maximum absolute error, mean square error and L2 norm. When the error is lower than a preset threshold, it is determined that the model has simulation accuracy. The system can automatically output an error evaluation report, support precision evaluation under complex topologies and disturbance conditions, and improve the efficiency and credibility of unmanned aerial vehicle cluster modeling verification.

The application discloses an experimental circuit and method based on a second-order dynamic circuit simulating a bomb defusing process, and relates to the technical field of teaching experimental circuits. The application comprises a second-order dynamic circuit, a logic judgment circuit, a timing display circuit and an external alarm circuit. The application uses a disconnecting switch to simulate the operation of cutting a wire in the bomb defusing process, uses a Laplace transform method to analyze the second-order dynamic circuit, converts the second-order dynamic circuit into a star connection through a star-delta conversion method, finally judges the wire breaking position, and uses an alarm lamp and a buzzer to simulate the bomb defusing effect. In the dynamic circuit, the breaking of three different wires will respectively cause the voltage of one node of the circuit to increase, remain unchanged or decrease. After the logic judgment circuit discriminates the voltage change, a logic control signal is generated to stop the countdown or trigger the external alarm device to alarm, so that the success or failure of the bomb defusing is simulated. The interesting experiment is used to guide students to analyze the second-order dynamic circuit by using the Laplace transform method.

The invention relates to a finite field convection-dispersion model composite solution and parameter inversion method under instantaneous source excitation, which comprises the following steps: establishing a one-dimensional finite length convection-dispersion mathematical model, carrying out dimensionless processing by selecting dimensionless factors such as Peclet number and dimensionless concentration, obtaining a frequency domain solution through Laplace transformation, and carrying out parameter inversion on the frequency domain solution. Adopting a Stehfest algorithm to realize Laplacian numerical inverse transformation to obtain a semi-analytical solution; combining COMSOL software to obtain a numerical solution of a dimensionless definite solution problem, and constructing a standard curve database containing multiple groups of parameters according to a semi-analytical solution; based on a one-dimensional indoor convection-dispersion test, an LTC three-parameter probe is used for real-time monitoring, according to a conductivity value, dimensionless concentration measured data is obtained, and accurate inversion calculation of a permeability coefficient, a longitudinal dispersion coefficient, a molecular diffusion coefficient, an average linear velocity, longitudinal dispersion and effective porosity is realized through a wiring method. According to the method, the parameter identification precision of the one-dimensional finite field convection-dispersion test under instantaneous source excitation is effectively improved.

The invention discloses a robust node classification and dynamic decision-making method for an agricultural pest and disease monitoring scene, and belongs to the technical field of agricultural information. The method comprises the following steps: fusing a crop spatial distribution topological structure and pest node attributes by utilizing topology-attribute joint embedding, obtaining hidden representation through symmetric normalized Laplace transformation, and decoupling the hidden representation into spatial features and semantic features by adopting an auto-encoder; carrying out bicubic interpolation processing on the heterogeneous node features acquired by the multi-modal sensor, and converting sparse unstructured node data into regularized structural data; a key feature channel is selectively enhanced through a feature enhancement module, a noise feature channel is suppressed, and the anti-interference capability of the model under field dynamic disturbance is improved; a deep convolutional generative adversarial network is adopted for robust training, the diversity of pest and disease data samples is expanded, and implicit regularization constraints are introduced. According to the method, the problems of sparse data, environmental interference, insufficient samples and the like in agricultural pest monitoring are effectively solved, and the monitoring precision and the model generalization ability are improved.

The application discloses a kind of energy storage converter asymmetric fault analysis methods based on virtual synchronous machine technology, using the vector control strategy based on internal potential orientation, grid-connected point voltage is separated into positive and negative sequence;According to asymmetric fault scene adjustment control link, including using trap filter to filter out the two-frequency fluctuation component in inverter output power, the reference voltage in reactive-voltage loop is switched from rated voltage to grid-connected point positive sequence voltage, negative sequence is inhibited by balance current strategy;Based on reactive-voltage circuit equation and reactive-voltage control equation, establish the equation about internal potential;According to virtual impedance ring control equation, calculate current reference value before fault and substitute into the virtual impedance ring control equation after Laplace transform, establish the equation about fault current dq axis component;According to the equation about internal potential and the equation about fault current dq axis component, construct the analytical expression of fault current.The application considers the influence of inverter control link on fault current transient characteristic, and analytical precision is high.

The invention discloses a road and bridge transition section slope difference detection method and system provided with a transition slab, and the method comprises the steps: determining a dynamic equation set of a target vehicle, and carrying out the Laplace transformation of the dynamic equation set, and obtaining a frequency domain forced vibration equation of the target vehicle; according to the acceleration information, the frequency domain forced vibration equation and the differential property of Laplacian transformation, constructing a frequency domain conversion relation between a preset symbol of the acceleration and the slope difference of the road and bridge transition section; determining acceleration information and final initial motion information when rear wheels of the target vehicle are in contact with the starting point of the approach road of the road-bridge transition section; and according to the acceleration information, the final initial motion information, the frequency domain forced vibration equation and the frequency domain conversion relation, the slope difference of the road and bridge transition section with the transition slab is determined. According to the method, the direct frequency domain conversion relation between the acceleration and the slope difference angle is established, the slope difference angle can be inverted only by collecting the acceleration of single pass, and the dependence of a traditional method on massive sample training, manual threshold calibration and professional equipment is eliminated.

The application discloses a deflection calculation method of a steel-concrete composite beam under uniform load, and relates to the technical field of high-speed railway bridge construction. The method comprises the following steps: a differential equation of a continuous steel-concrete composite beam is established, and Laplace transformation is performed to obtain an expression of non-zero real number solution; inverse transformation is performed on the equation after the Laplace transformation to obtain an analytical expression of the deflection of the composite beam, which contains multiple unknown quantities. The structural parameters and material parameters of the composite beam are substituted into the non-zero real number solution expression to solve the Laplace transformation parameters; the parameters and boundary conditions are substituted into the deflection analytical expression to obtain matrix elements for solving the unknown quantities; a linear equation set is constructed, the unknown quantities are solved, and then are substituted into the deflection analytical expression to finally obtain a complete expression for solving the deflection of the continuous composite beam. The complete expression of the deflection of the continuous composite beam provided by the application is suitable for analyzing the deflection of a single-span or continuous steel-concrete composite beam, and has high calculation precision.

This invention discloses an analytical method for micro-water testing and permeability coefficient inversion considering a finite-thickness negative thin-walled layer and the non-Darcy effect within the layer. A mathematical model for micro-water testing considering the finite-thickness negative thin-walled layer and the non-Darcy effect within the layer is constructed. Based on the radial dual-zone medium assumption, seepage within the negative thin-walled layer is generalized as Forchheimer-type seepage, while seepage within the aquifer is linear Darcy flow. The Laplace transform and Brady method are introduced to handle the nonlinear terms, and the well water level is derived. H ( t Semi-analytical solutions in semi-infinite and finite domains. During parameter inversion, high-frequency, high-precision water level gauges deployed in the test well are used to collect water level response data after excitation, generating... H Follow t The permeability coefficients of the negative thin-walled layer and the aquifer are calculated simultaneously by comparing the measured curves with the standard curves and then performing inversion calculations. K i This invention is the first to achieve simultaneous inversion of the permeability coefficients of negative thin-walled layers and aquifers, and significantly improves the efficiency of permeability coefficient measurement in micro-water tests. K i The accuracy of the value.

The application discloses a micro water test model analysis and permeability coefficient value inversion calculation method based on a nonlinear seepage theory, establishes a complete well micro water test analysis model of a confined aquifer which can explicitly describe the influence of the global non-Darcy effect in the aquifer, adopts a Forchheimer equation to describe a nonlinear seepage field, processes the nonlinear term by using a Laplace transform and a Brady method, and realizes accurate solution of well water level H(t) by using a Talbot algorithm for numerical inversion. High-frequency and high-precision water level pressure sensors arranged in a test well and at different observation points are used to collect and record water level distribution of an initial background seepage field and water level response data after a micro water test is excited, so that the seepage state of the seepage field in the aquifer is determined. In the inversion process of the permeability coefficient value of the aquifer, a change rule curve of the well water level H with time t is generated based on the water level response data of the test well, and the permeability coefficient K value of the aquifer is inverted by comparing the fitting of the measured value with a standard curve.