20 results about "Superposition principle" patented technology

The application discloses a micro-nano circular plate fracture analysis method considering coupling of surface effect and plastic zone, and firstly establishes a three-dimensional curved surface coordinate system suitable for a surface layer, and then further corrects a Dugdale cohesion force model according to a superposition principle after considering surface correlation of the plate, and then simplifies the Dugdale cohesion force model into a hyper-singular integral equation by using Hankel transformation, and finally obtains influences of the surface effect on the plastic zone size and crack surface displacement by numerically solving the hyper-singular integral differential equation.The method can accurately capture the nonlinear coupling relationship between the crack size, the surface shear modulus, the torsional displacement and the stress intensity factor under the micro-nano scale, effectively corrects calculation deviation generated by traditional classical theory when the surface effect is ignored, ensures the accuracy of the fracture analysis under different scales, and realizes more accurate and more comprehensive theoretical description of the elastic-plastic fracture behavior of the micro-scale material.

This invention provides a method for predicting surface vibration waveforms during tunnel blasting, comprising: first, deriving the vibration waveform function of a short-charge explosive charge based on Heelan theory; then, constructing a vibration calculation form suitable for tunnel cut-out blasting based on this short-charge explosive charge vibration waveform function, and calculating the surface vibration waveform function of the cut-out holes using the superposition principle; next, simplifying and correcting the formula for the waveform function of multiple-hole blasting to obtain the surface vibration waveform function of multiple-hole blasting in the tunnel; finally, determining the specific parameters in the formula by comparing with field measured data, and obtaining a surface vibration waveform function curve suitable for field use. This method can comprehensively and accurately predict the waveform time history curve of the entire process of surface vibration during tunnel blasting, rather than just predicting a single blasting peak value. It can effectively promote the field application of surface vibration waveform prediction for tunnel blasting and is of great significance for optimizing blasting parameters and ensuring the safety of various facilities and personnel around the blasting area.

The application discloses a preliminary design rapid estimation method and system for tower deviation of a multi-tower cable hoisting system, and relates to the field of tower deviation estimation in bridge construction technology.The estimation method comprises the following steps: calculating the single-span horizontal elastic stiffness of each span compression tower cable based on an equivalent elastic modulus method; calculating the total equivalent stiffness of each tower according to a series stiffness model, specifically comprising the following steps: first, calculating the corresponding left series stiffness and right series stiffness, and then adding the left series stiffness and the right series stiffness to the self equivalent stiffness of the tower to obtain the corresponding total equivalent stiffness; when a single tower is subjected to an external force, calculating the self deviation and the collaborative deviation of the adjacent tower based on a deviation influence coefficient; and when multiple towers are simultaneously subjected to force, calculating the total deviation of any tower by using a superposition principle.The application is suitable for rapid scheme comparison and selection in the preliminary design of a multi-tower cable hoisting system with any number of spans and towers, and has the advantages of strong universality, reliable precision, easy implementation and the like.

The application discloses a common-mode electromagnetic interference modeling method, equipment, medium and product for a gallium nitride synchronous step-down converter, relates to the technical field of electromagnetic compatibility and power electronic modeling, and comprises the following steps: determining a common-mode conduction path, and then determining an EMI noise source; constructing an equivalent circuit of the gallium nitride synchronous step-down converter based on the EMI noise source; constructing a voltage-dependent nonlinear equivalent capacitance model of a switching device in the gallium nitride synchronous step-down converter, and further constructing an analytical model of the gallium nitride synchronous step-down converter; determining simulation data of the analytical model; constructing a unified composite excitation source based on the simulation data by using the superposition principle; replacing the EMI noise source in the equivalent circuit with the unified composite excitation source to obtain a unified CM-EMI model, and then obtaining a final common-mode electromagnetic interference model. The application can improve the prediction accuracy of high-frequency resonance.

The application discloses a numerical control machine tool precision distribution method from geometric error to manufacturing tolerance, comprising: using small deformation hypothesis and superposition principle to obtain the influence coefficient matrix of manufacturing tolerance to position related geometric error, and combining with the machine tool motion chain to establish a manufacturing tolerance-geometric error-space error three-layer mapping model; adopting Sobol total effect sensitivity analysis of the overall workspace characteristic trajectory to obtain the total effect sensitivity index of each manufacturing tolerance; establishing a manufacturing cost evaluation model, and combining with the total effect sensitivity index to construct a cost sensitivity index; taking the minimum manufacturing cost as the target, comprehensively considering the tolerance definition domain constraint, the sorting constraint and the space error confidence constraint, and using an optimization algorithm to realize precision distribution. The application traces the precision distribution from the abstract geometric error level to the part manufacturing tolerance level, and can further realize the collaborative optimization of machine tool precision design and manufacturing cost.

The present application is applicable to the technical field of underground engineering, and solves the problem of the limitation of the existing analytical method in calculating the stress of non-circular single-hole surrounding rock. The present application provides an iterative calculation method for the stress of non-circular single-hole surrounding rock under support, which comprises establishing a mathematical model for the excavation model of non-circular single-hole under ground overload, and decomposing the mathematical model according to the superposition principle, and iteratively calculating the convergence value of the equivalent concentrated force of the model for several times to determine the stress value of the surrounding rock at any point around the hole. The present application can simultaneously consider the effects of ground overload, support load and initial ground stress, and the calculation process is relatively simple, the application range is wider, the stress concentration degree at the corner point calculated is higher, and the calculation result is accurate.

This invention discloses a method for predicting and avoiding the phase tuning of self-excited vibrations in rotating machinery based on the principle of symmetry. The method includes: considering the rotating machinery as a rotating mechanism formed by several coaxially mounted central components and several intermediate force-transmitting components mounted circumferentially; calculating the spatiotemporal excitation phase of each intermediate component based on the spatial rotational symmetry of the topological structure and the time-translational symmetry of the time-varying excitation; providing a Fourier series characterization of the time-varying excitation at each intermediate component based on symmetry; considering the elastic out-of-plane vibration of the central component, calculating the out-of-plane component of the time-varying excitation, and calculating the resultant force and resultant moment in the six degrees of freedom directions using the superposition principle; analyzing the value characteristics of the resultant force and resultant moment using the properties of trigonometric functions, and predicting the typical self-excited vibration modes of the central component. This invention provides technical support for the cancellation of time-varying self-excited forces, prediction of vibration behavior, and parameter selection in rotating machinery. This technology has significant advantages such as accuracy, universality, and high efficiency.

The application discloses a kind of gas-water co-production tight gas reservoir fracturing horizontal well pseudo-steady state productivity calculation method, the application considers gas-water two-phase flow simultaneously by superposition principle, establishes the productivity equation of pseudo-steady state stage of multi-section fracturing horizontal well, analyzes the influence of factors such as fracture number, fracture half-length, production gas-water ratio, starting pressure gradient, slip effect, effective permeability and fracture conductivity on initial open flow capacity of gas well.The specific productivity equation construction steps are as follows: S1, establish single fracture single-phase gas productivity equation;S2, ignore the difference between fracturing cracks to establish single-phase gas well total productivity equation;S3, two-phase pseudo-pressure is introduced into gas well productivity equation to obtain gas-water two-phase fracturing horizontal well productivity equation;S4, slip factor, starting pressure gradient nonlinear factor two factors are introduced into two-phase fracturing horizontal well productivity equation.

The application discloses a kind of super long spliced guide rail straightness prediction methods considering multi-source error, belong to precision machinery manufacturing and measurement technical field. Including: the mathematical model of guide rail surface initial manufacturing error is established;Subsection independent integration method is applied, and the deflection deformation analytical model of guide rail caused by gravity load is established;By parameterization modeling and finite element simulation are combined, the parameterization simulation model of splicing surface geometric error and bolt pretightening force coupling effect is established, and splicing error function is extracted;Based on linear superposition principle, the above three independent error models are algebraically superimposed, and the guide rail comprehensive straightness prediction model is constructed.The strong nonlinear coupling effect of splicing interface is accurately quantified by parameterization means, forming a set of high-precision forward-looking prediction method that can be used in design or installation stage, which provides an effective theoretical tool for the precision design and process control of super long spliced guide rail.

The application relates to an oil well well spacing optimization method and device for edge-bottom water reservoirs, and the method comprises the following steps: based on oil well well spacing and parameter data, the pressure distribution of the edge-bottom water reservoir under the condition that an arbitrary number of oil wells are simultaneously and stably produced is calculated by using a mirror image superposition principle; based on the pressure distribution of the edge-bottom water reservoir, the movement trajectory of fluid in the edge-bottom water reservoir is calculated and drawn by using a Pollock method, and the movement trajectory of the fluid is a streamline; the water saturation at an arbitrary time and an arbitrary position along the streamline is calculated by using a Buckley-Leverett method, so that the water saturation distribution in a two-dimensional simplified model is obtained, and the time for the water drive front saturation on each streamline to move from a supply boundary to the bottom of the oil well is calculated, so that the water drive front breakthrough time is determined; based on the water drive front breakthrough time, a relationship curve between the oil well well spacing and the cumulative oil production is drawn, and the optimal oil well well spacing of the edge-bottom water reservoir is determined.

The application discloses a dam creep parameter self-adaptive inversion method based on a variable-order fractional constitutive model, and comprises the following steps: acquiring measured displacement time series of multiple measuring points and load and environmental action time courses, and constructing a three-dimensional finite element model; constructing a variable-order fractional Burgers constitutive relationship reflecting the activity attenuation characteristics of concrete creep; discretizing a dam service period into multiple subintervals, and applying a superposition principle to calculate the partial strain increment of each subinterval in a segmented constant-order framework to obtain a variable-order fractional forward calculation model; constructing an inversion objective function, dividing the parameters to be inverted into a mechanical parameter group and a fractional-order evolution parameter group; alternately optimizing the mechanical parameter group and the fractional-order evolution parameter group to obtain and output a final inversion parameter set. The application solves the conflict between the aging material and the superposition principle, eliminates the inconsistency defects of the heterogeneous parameter joint inversion, and improves the physical rationality and numerical stability of the long-term service state prediction of the dam.

The application relates to a modeling method and device for a combined scattering field of a rough surface in a terahertz frequency band. The method comprises the following steps: performing normalization processing on the normal RCS of a single hemisphere, performing fitting characterization on the result, then correcting an approximate formula of the scattering field of the hemisphere by using the normalized RCS, solving the scattering field of a larger radius hemisphere, constructing a phase factor of the scattering field of the hemisphere at different positions by using the relative position relationship of the hemisphere, deducing a scattering field expression of a hemisphere array based on a vector superposition principle, determining the energy ratio of non-coherent scattering field and coherent scattering field according to the ratio of the area of the planar element covered by the hemisphere to the area of the planar element not covered by the hemisphere, performing vector superposition on the scattering field of the hemisphere array and the scattering field of a smooth flat plate based on the superposition idea of non-coherent and coherent scattering, and solving the scattering field of the hemisphere-flat plate combination after the normal RCS of the hemisphere-flat plate combination is corrected. The method can improve the modeling efficiency of the rough surface in the terahertz frequency band.

The application discloses a blasting vibration prediction method based on an explosion source model, obtains vibration waveforms at different positions and distances from a blast center in spherical coordinates based on a spherical charge explosion source model, equivalent column charges are superimposed on multiple spherical charges, vibration waves generated by multiple equivalent spherical charges at space particles are superimposed according to a vibration wave superposition principle, so as to obtain vibration waveforms of space particles under column charge conditions, and considering the existence of a free surface, according to a wave reflection law, a reflected wave can be regarded as an incident wave generated by a virtual explosion source, and the incident wave of a real explosion source and the incident wave generated by a virtual explosion source corresponding to the real explosion source can be superimposed according to the vibration wave superposition principle, so that a complete vibration waveform of a target particle can be obtained, and waveform parameters such as a peak vibration velocity, a frequency and a frequency width can be obtained based on the waveform.

The application provides a multistage fracturing horizontal well multi-well interwell connectivity analysis method and system based on interference well testing, considers uneven fracture distribution and different fracture connectivity states of a shale gas fracturing horizontal well group, establishes a Laplace space multi-well interference well testing analysis model of the multistage fracturing horizontal well based on percolation mechanics and pressure superposition principle, solves the multi-well interference well testing model of the fracturing horizontal well to obtain a Laplace space multistage fracturing well bottom hole pressure solution, carries out numerical inversion on the Laplace space multistage fracturing well bottom hole pressure solution to obtain a real space multistage fracturing horizontal well bottom hole pressure solution, and then uses the real space multistage fracturing well bottom hole pressure solution and measured bottom hole pressure data to carry out fitting inversion to obtain reservoir parameters and fracturing reconstruction parameters. The scheme can overcome the defects of limited application and insufficient operation precision of the prior art, considers the asymmetry and flow conductivity of fractures about the horizontal wellbore in different connectivity states, and is efficient, and gives consideration to calculation stability and timeliness.

The present application relates to the technical field of photoelectric detector testing, and discloses a standard evaluation method for linearity of photoconductive signals of a tester, comprising: configuring an independent driving narrow-band light source coupled to an integrating sphere to build a binary-weighted light flux synthesis environment; measuring a thermal time constant of a detector, defining a test cycle containing a measurement time slot and a thermal compensation time slot, and setting a single-cycle target total dissipated energy; opening a light source combination according to a binary control code, collecting instantaneous response current under the condition that a constant measurement bias voltage is applied to maintain a constant internal electric field of the detector; calculating an energy gap based on the principle of energy conservation, applying a dynamic compensation voltage pulse to perform dark-state thermal injection in the thermal compensation time slot, and maintaining a constant detector lattice temperature; traversing the full dynamic range, and calculating linearity deviation by using the superposition principle. The time-division multiplexing electrothermal compensation mechanism keeps the total dissipated energy of the detector constant during the testing process.

This invention discloses a method for calculating the production rate of fractured wells in heterogeneous tight oil reservoirs considering the initiation pressure gradient. First, based on the closed boundary point source function, a multi-scale seepage model of matrix seepage in heterogeneous tight oil reservoirs is established using Green's formula and Newman integral. Then, according to the skin principle, a negative skin coefficient is introduced to describe the influence of the fracture network stimulation zone on seepage, resulting in a flow characterization model of the fracture network stimulation zone. Next, the main fracture flow equation is established, and the pressure drop equation of a single discrete fracture unit is described using Darcy's law. The pressure drop characterization model from any discrete unit to the horizontal wellbore is calculated using the pressure drop superposition principle, resulting in the main fracture flow characterization model. Finally, a production rate calculation model for fractured wells in heterogeneous tight oil reservoirs is coupled and established. The steady-state production processes of fracture micro-segments within each small time interval are superimposed, and a heterogeneity coefficient is established based on the skin principle, resulting in a production rate calculation model for fractured wells in heterogeneous tight oil reservoirs under variable production conditions. This method enables rapid and effective, precise prediction of production rates.

The application discloses a kind of analytical calculation method for the surface laying thickness of antifreeze insulation layer of deep-buried tunnel in cold region, comprising the following steps: establishing tunnel antifreeze insulation layer, lining structure, annual temperature amplitude and annual average temperature along the radial depth analytical calculation model of surrounding rock;Considering the influence of the thermal physical property difference of different material layers on the change of tunnel temperature field, calculate the heat storage coefficient and surface heat storage coefficient of each material layer;Calculate the annual temperature amplitude distribution along the radial depth of tunnel;Determine the temperature influence boundary and its depth of tunnel surrounding rock;Calculate the annual average temperature of waterproof plate position between tunnel secondary lining and primary support;Calculate the annual minimum temperature of waterproof plate position, determine the required antifreeze insulation layer thickness.The application is based on superposition principle, steady-state heat transfer principle and periodic heat transfer principle for theoretical derivation, obtain a simple, easy-to-promote analytical calculation method for the surface laying thickness of antifreeze insulation layer of deep-buried tunnel in cold region, for guiding tunnel antifreeze insulation layer design.

The present application is suitable for geotechnical engineering technical field, and is used for solving the problem that complex variable function method cannot be used in actual engineering, and overcomes the problem that complex variable function method is only suitable for specific slope angle and cannot solve the slope stress field with arbitrary slope angle. The present application provides a kind of multi-stage slope elastic stress iterative calculation method under supporting action, which comprises establishing a mathematical model for n-stage slope under the action of initial ground stress, slope top overload, reinforcement supporting force; according to the superposition principle, the mathematical model is decomposed and the corresponding stress is calculated, and the stress of multi-stage slope is obtained according to the superposition principle. The present application is used for solving the stress of multi-stage slope under the premise of considering the influence of initial ground stress, overload, supporting pressure and anchoring force and other load actions, can solve the slope stress field with arbitrary slope angle, and the calculation result is accurate, and the stress concentration degree near the slope toe is high.