75 results about "Mechanical equilibrium" patented technology

The invention provides a rotary table bearing-torque motor thermal vibration coupling modeling method, and relates to the technical field of machine tool reliability analysis. Comprising the steps of calculating bearing restoring force, torque and elastic rigidity; giving a dynamic balance equation of the main shaft system; unbalanced magnetic pulling force and unbalanced mass excitation are calculated; a displacement field is solved, and load changes caused by the displacement field are transmitted to the thermal model; the contact force borne by the bearing is updated by considering the load effect related to displacement, and the friction heat generation of the bearing and the heat generation of each part of the motor are calculated; calculating thermal deformation and thermal displacement of the bearing; thermal resistance among nodes is calculated, and a temperature field equilibrium equation is given through a thermal resistance network to achieve rapid thermal-mechanical coupling analysis; the thermal equilibrium equation is solved to calculate temperature response; importing the latest temperature into the kinetic model; lubricating grease viscosity and bearing thermal deformation are updated; and repeating the steps to finally obtain the main shaft displacement field and temperature field response. The method is high in accuracy, high in universality, low in test cost and high in test efficiency.

The invention relates to the technical field of shield tunnel engineering, and discloses a backward shield tunnel face support pressure calculation method suitable for high-water-pressure permeable stratum shield in-ground butt joint, which comprises the following steps of: establishing a shield in-ground butt joint balance relation in combination with mechanical equilibrium analysis in a shield in-ground butt joint process; calculating the penetration resistance of the cutter at different tunneling speeds based on a butt joint adjacent stratum penetration resistance test; the supporting pressure of the backward shield tunnel face is calculated, and tunneling construction is guided through the supporting pressure of the backward shield tunnel face at different tunneling speeds. According to the method, the problem of parameter setting in the proximity tunneling process of the following shield can be effectively solved, the balance formula has universality for similar shield butt joint projects, the corresponding relation between the penetration resistance and the tunneling speed of the butt joint position can be truly reflected through the penetration resistance test of the near ground layer, and the method has the advantages of being high in practicability and the like. And the set value of the supporting pressure of the tunnel face of the subsequent shield is obtained, and a theoretical basis is provided for setting tunneling parameters of the subsequent shield.

The invention discloses a method for establishing a soil body freezing characteristic curve based on a thermodynamic principle. The method comprises the following steps: step 1, determining zoning characteristics of the soil body freezing characteristic curve; 2, determining an ice water chemical potential balance equation in the freezing process; 3, determining an ice water mole entropy equation and a phase change latent heat equation; 4, determining a soil mechanical equilibrium equation and a freezing temperature equation; 5, determining a capillary effect equation and a freezing temperature equation of capillary pores; and 6, determining a pore size distribution equation, and determining a soil body freezing characteristic curve. According to the thermodynamic principle and the microscopic physical structure of the soil body pores, a theoretical model capable of representing the change rule of the unfrozen water in the soil body freezing process with high precision is established, the quantitative relation among the freezing temperature, the content of the unfrozen water and the pore structure parameters is defined, the application range is wide, and the method is suitable for large-scale popularization and application. And theoretical support is provided for related research of the soil freezing process.

The utility model provides a slag pan residue crushing device which comprises a crown block, a lifting appliance and a crushing hammer, the lifting appliance is connected with the crown block through a chain, the crushing hammer is hung on the lifting appliance, and the crown block can lift the crushing hammer through the lifting appliance; after the crown block lifts the breaking hammer to a preset height, the breaking hammer and the lifting appliance can be automatically unlocked, and the breaking hammer falls into the slag tray, so that the slag in the slag tray is broken. The crushing device is based on the mechanical balance principle, the dead weight of the slag disc is converted into an unlocking power source of the crushing hammer, residues in the slag disc can be efficiently crushed without additional energy drive, the structure is simple, the cost is low, durability is achieved, manual intervention is greatly reduced, and the labor intensity of personnel is reduced.

The invention provides an unconventional oil and gas reservoir heat-fluid-solid coupling numerical simulation method and system. The method comprises the steps that a multiphase numerical model of a coupling temperature field, a seepage field and a stress field is built; the multiphase numerical model is integrated with a Cahn-Hilliard equation, a heat conduction equation, a continuity equation, a Navier-Stokes equation and a mechanical equilibrium equation; determining a model computational domain of the multiphase numerical model; performing grid discretization processing on the model calculation domain and performing grid refinement processing on the peripheries of the mass flow inlet and the pressure outlet to obtain a plurality of grid units; inputting the environmental parameters and the initial condition parameters into the multiphase numerical model, controlling the multiphase numerical model to perform discrete calculation in each grid unit, judging whether a convergence condition is met or not, and if yes, updating the physical property parameters of the multiphase fluid according to the current temperature and pressure, and outputting a numerical simulation result of the unconventional oil and gas reservoir. According to the invention, the productivity prediction deviation can be reduced.

This invention discloses a phase-field method for multi-topological domain cyclic transformation in lead titanate (PTO) ferroelectric thin films. A computational model of the PTO ferroelectric thin film is established, defining polarization, potential, displacement, and oxygen vacancy concentration as field variables. Based on Ginzburg-Landau theory, a total free energy expression for the PTO ferroelectric thin film is established, incorporating oxygen vacancy transport processes and the coupling between oxygen vacancies and the electrostatic field. Combining time-correlated Ginzburg-Landau kinetic equations, mechanical equilibrium equations, electrostatic equilibrium equations, and Nernst-Planck equations, a phase-field model of the PTO ferroelectric thin film coupled with multiple physics fields is established. A stable initial skyrmion domain structure is constructed, and a preset uniform electric field sequence is applied to simulate the cyclic transformation process between skyrmions and flux-closed domains and / or stripe domains. This method can analyze the evolution path, transformation threshold, oxygen vacancy distribution, and cyclic stability of topological domains in PTO ferroelectric thin films under the synergistic effect of an applied electric field and oxygen vacancies, providing a theoretical basis for the design of ferroelectric topological domain multi-state storage devices.

According to the method and device for in-situ survey of the water pressure borne by the underground structure, the value of the water pressure borne by the outer surface of a structure in an underground water-soil mixture on the unit area is measured according to the Newton's third law, namely the principle that acting force is equal to counter-acting force. Providing a measuring device at least comprising a survey hole, a load system and an underground water level control system; the acting force along the gravity direction is reduced in a step-by-step unloading mode, so that the measuring bottom plate tends to a static unbalance state and enters different self-stabilization balance states; along with the gradual increase of unloading, the counterforce of the soil spring in the reverse gravity direction is gradually reduced; recording the motion state of the measuring bottom plate under each stage of load, and obtaining a previous self-stabilization equilibrium state closest to the state by recording the violent floating motion state of the measuring bottom plate; the tiny soil reaction force in the self-stabilization equilibrium state is ignored, and according to a mechanical equilibrium equation, the total lower pressure value on the measurement bottom plate in the state is approximately taken as the underground water pressure value borne by the measurement bottom plate.

The application discloses a short yarn conveying automatic yarn laying system dynamic process tension control method and device, belongs to the technical field of automatic prepreg tow laying, and comprises the following steps: a mechanical equilibrium equation group considering the gravity of a floating part, friction between the floating part and a guide rail and an 'inertia force' caused by acceleration is established, real-time yarn tension is solved, and equivalent deformation of a tension spring is calculated based on the yarn tension. The torque of a hysteresis device is adjusted and the tow tension is controlled by comparing the equivalent deformation of the tension spring and the deformation of the tension spring at a balanced position. The tow tension calculated by the scheme has high precision, and the tension control precision of the short yarn conveying automatic yarn laying system dynamic process is improved.

The invention discloses a method and a system for calculating sediment pressure in a salt cavern. The method comprises the following steps: dividing a salt cavern cavity form containing a sediment part; determining the distribution of a corresponding cavity wall side pressure coefficient along with the depth according to the cavity form, wherein the cavity wall side pressure coefficient is the ratio of the normal supporting force to the vertical stress of the cavity wall; constructing a sediment mechanical model at any depth in the salt cavern cavity containing the sediment part, and carrying out mechanical equilibrium analysis; and calculating the vertical pressure of the sediment at different depths in the cavity according to the cavity form, the distribution of the cavity wall side pressure coefficient along with the depth and the sediment mechanical model at any depth in the cavity. The method can adapt to different salt cavern forms and sediment distribution, cover conical, spherical and mixed cavity types, support different sediment accumulation scenes, accurately calculate the pressure of the sediment on the cavity wall, facilitate better understanding of the stress condition in the salt cavern energy storage reservoir, and have important significance for ensuring the long-term stability of the salt cavern energy storage reservoir.

This invention belongs to the field of tunnel construction technology and discloses a method and system for determining the support force of a shield tunneling machine (TBM) under riverbed strata with elevation differences. This method combines wedge failure theory and the limit equilibrium method, establishing a model that treats the actively failing soil in front of the TBM excavation face as a prism plus a wedge. It analyzes the mechanical equilibrium of the TBM support force and the sliding soil under the limit equilibrium state, dividing the river crossing process into five stages and calculating the support force at the excavation face of each uneven stratum under the river, thereby determining the magnitude of the ultimate support force at the excavation face of the TBM under the riverbed. This invention simplifies the wedge theory calculation model, avoiding complex formulas and cumbersome calculation steps, and accurately calculates the ultimate support force at the bottom of the riverbed, the river slope, the bottom layer without a riverbed, and the boundaries between different strata. This makes the support force calculation more consistent with actual engineering conditions, laying the foundation for subsequent theoretical analysis and technological development.

The invention relates to the technical field of roof cutting pressure relief gob-side entry retaining, in particular to a working face roof advanced pressure relief dense hole arrangement parameter design method which comprises the steps that S1, based on dense hole rock macroscopic stress analysis, a calculation relation between dense hole rock macroscopic stress and dense hole plastic zone development radius is established; step S2A, selecting a strength criterion, calculating a dense hole plastic zone development radius, and determining dense hole arrangement spacing; step S2B, based on dense inter-hole rock infinitesimal body stress analysis, establishing a dense inter-hole rock infinitesimal body mechanical equilibrium equation, and in combination with a Mohr-Coulomb strength criterion, establishing a calculation relationship between dense inter-hole rock infinitesimal body stress and an advanced working face distance; and S3, selecting according to a strength criterion, correspondingly establishing an equivalent relationship between the macroscopic stress of the rock among the dense holes and the stress of the infinitesimal body of the rock among the dense holes, forming a calculation relationship between the advance working face distance and the development radius of the plastic zone of the dense holes, and quickly determining the arrangement parameters of the dense holes.

The invention discloses a synchronous closure method for a multi-span continuous rigid frame bridge, which comprises the following steps: (1) deflection calculation theory analysis under asynchronous closure, including the following sub-steps: a proportionality coefficient v formed at a K point in a Jth stage is a time function related to a loading period age psi; unifying the loading time and the actual time coordinate of the site; deflection calculation under the action of self weight, wherein deflection formed by prestress tension is calculated; calculating the deflection of the K point after the Jth section is tensioned under the asynchronous closure; (2) deflection calculation theoretical analysis under synchronous closure: the deflection calculation theoretical analysis under the synchronous closure of the bridge mainly considers the stress and deformation of the structure, a finite element method is adopted to discretize the bridge into a plurality of units, and a mechanical equilibrium equation is solved to solve the deflection; and (3) based on a finite element analysis platform, establishing a comparison model of a span-by-span closure process and a synchronous closure process. A construction scheme which is correct in line shape, reasonable in stress and fast in bridge forming is provided for the continuous rigid frame bridge.

The invention provides a geothermal reservoir fracturing-exploitation integrated numerical simulation method and system, and the method comprises the steps: firstly constructing a strong coupling model covering heat-hole-elastic mechanics, building a heat and mass transfer and mechanical equilibrium equation of a matrix and a crack, and forming a unified calculation framework, secondly, constructing a three-dimensional curved surface crack model and a triangular mesh topology by adopting an extended embedded discrete crack method, and establishing a spatial relationship between cracks and a matrix and a spatial relationship between the cracks; then, based on the geometric model, utilizing a displacement discontinuous method to calculate fracture opening and stress shadow, solving a heat-fluid-solid model through iterative coupling, and completing dynamic evolution simulation of a three-dimensional fracture group in a fracturing stage; and finally, the fracturing result serves as the initial condition of the mining stage, the injection-production cycle process is solved through a finite volume / finite element method, and seamless connection of fracturing and mining is achieved. According to the method, the three-dimensional crack propagation and heat extraction efficiency under the thermal-hole-elastic coupling effect can be accurately predicted.

The invention discloses a flow velocity measuring device and method based on the mechanics principle. The flow velocity measuring device comprises a sphere, a flexible connecting piece, a measuring part and a data processing part, wherein the sphere serves as a flow sensing element and is slightly higher than water in density. During measurement, the ball body is immersed in water flow to be measured, and the ball body reaches mechanical balance under the action of gravity, buoyancy, water flow resistance and thin wire tension. The tensile force of the flexible connecting piece is measured in real time through the measuring component, the data processing component calculates the resistance of the water flow acting on the sphere based on an established mechanical equilibrium model, and then the instantaneous flow velocity of the fluid is accurately and reversely calculated according to the square relation between the resistance and the flow velocity. The defects that a traditional flow meter is complex in structure, high in cost, poor in environmental adaptability and the like are overcome, and a flow velocity measurement solution which is simple in structure, low in cost, high in measurement precision and easy to maintain is provided.

The invention discloses a construction-considered servo type supporting foundation pit mechanical calculation model and an axial force optimization method, and the calculation model comprises the steps: solving a basic mechanical equilibrium equation, and solving the basic mechanical equilibrium equation to obtain the lateral displacement of an enclosure wall body in each construction step and the axial force of each support; the axial force optimization method comprises the following steps: S1, establishing an initial system; s2, optimized support unloading is carried out; and S3, optimizing support loading. The method has the advantages that automatic adjustment and optimization of the servo type support axial force can be achieved through programming, so that the design calculation efficiency is improved, a theoretical basis is provided for determining the control axial force of the servo type support in actual engineering application, and the foundation pit deformation control effect is enhanced.

The invention discloses a method for designing and calculating the width of a sealing surface of a mechanical seal. The method comprises the following steps: S1, acquiring end surface morphology parameters, working condition parameters, the inner diameter of the sealing surface and interface parameters of a dynamic ring and a static ring of the mechanical seal; s2, determining the wettability of the dynamic and static ring sealing surfaces according to the sealing surface interface parameters of the dynamic and static rings; s3, determining the maximum height of the dynamic and static ring contact interface gap according to the end surface morphology parameters of the dynamic and static rings; s4, determining the capillary pressure of the contact interface of the dynamic and static rings according to the sealing surface interface parameters of the dynamic and static rings; s5, establishing a mechanical equilibrium equation in the capillary gap of the contact interface of the dynamic ring and the static ring; and S6, calculating the width of the sealing surface according to a mechanical equilibrium equation and the inner diameter of the sealing surface. The problem that the sealing face is too wide or too narrow due to the adoption of an empirical mode can be effectively solved, the capillary effect of the sealing face can be fully played under the reasonable sealing width of the mechanical seal, the leakage suppression effect is achieved, leakage is avoided, and the sealing performance of the mechanical seal is improved.

The invention discloses a counter-force detection and jacking-free replacement method and system for an existing support. The method comprises the following steps that a height-adjustable supporting device and a deformation monitoring element are arranged on the side face of the existing support according to needs; releasing the constraint of the upper plate and the beam bottom, slowly adjusting the height of the supporting device, and monitoring the height change of the support and the adjusting power of the supporting device corresponding to the height value in real time; collecting an adjusting power value when the height of the support does not change any more and / or collecting an adjusting power value when the adjusting power and time relation is in a smooth section; when the height of the support does not change any more, the support is completely unloaded, the support is taken out, a new support is installed, and replacement of the support is completed; a vertical force value is obtained by combining the mechanical relation between the vertical counter force of the supporting device and the adjusting power, and the vertical counter force value can be known to be the counter force of the support in the initial state according to the mechanical balance relation of the supporting point; and the power of the supporting device is gradually unloaded until the power is completely unloaded, and the supporting device is taken out. According to the invention, the counter-force monitoring of the existing support can be realized, and the rapid replacement of the existing support can also be realized.

The application provides an overhead line construction tension intelligent control and sag real-time measurement method and system, and belongs to the technical field of overhead lines. The method comprises the following steps: acquiring construction terrain geometric data, meteorological environment data, environment interference data, conductor self data and current tension data; judging the current tension data based on the environment interference data; if the current tension data is valid, inputting the preset target sag, meteorological environment data, conductor self data and terrain geometric data into a tension calculation model based on a mechanical equilibrium equation to obtain target tension data; calculating the deviation value of the target tension data and the current tension data, inputting the proportional-integral-derivative control operation, obtaining the tension control amount, driving the tension machine actuator to adjust the conductor tension to obtain the adjusted tension; and calculating the current sag value based on the terrain geometric data, conductor self data, adjusted tension and meteorological environment data, and correcting the current sag value to obtain the output sag value.

The invention discloses a pure rolling rigid hinge beam mechanical standard static strain generating device which comprises a horizontal base station, ball linear guide rails are arranged on the horizontal base station, and a speed reducer, a left knife edge and a right knife edge are arranged on a micro-motion short roller guide rail between the two ball linear guide rails. The speed reducer is connected with the two knife edges through lead screws so that the speed reducer can drive the two knife edges to do axial translational motion, and the speed reducer is in transmission connection with the servo motor. The tail end of the outer side of the ball screw is sleeved with the corresponding cylindrical rolling bearing and abuts against the compression spring. The tool apron fixes one end of each force rod, the two force rods are supported through six sets of equal-height steel ball supporting columns, loading openings for clamping the calibration beam are formed in the force rods, and wedge-shaped self-locking clamping mechanisms are arranged in the loading openings to guarantee locking of the calibration beam. By means of the structure, an unconstrained ideal rigid closed plane static mechanical equilibrium system can be achieved, loading of a normal-temperature calibration beam + / -5000 mu epsilon and loading of a Kt beam + / -3000 mu epsilon can be achieved, and therefore the strain measurement precision is improved, and the strain measurement range is widened.

The application provides an unconventional oil and gas reservoir thermal fluid-solid coupling numerical simulation method and system, and the method comprises the following steps: constructing a multiphase numerical model coupling a temperature field, a seepage field and a stress field; the multiphase numerical model integrates a Cahn-Hilliard equation, a heat conduction equation, a continuity equation, a Navier-Stokes equation and a mechanical equilibrium equation; determining a model calculation domain of the multiphase numerical model; performing grid discretization processing on the model calculation domain and performing grid refinement processing on the periphery of a mass flow inlet and a pressure outlet, thereby obtaining a plurality of grid units; inputting environmental parameters and initial condition parameters into the multiphase numerical model, controlling the multiphase numerical model to perform discrete calculation in each grid unit, judging whether a convergence condition is met, if the convergence condition is met, updating physical property parameters of a multiphase fluid according to a current temperature and pressure, and outputting a numerical simulation result of the unconventional oil and gas reservoir. The application can reduce the production capacity prediction deviation.

The present invention belongs to the field of mechanical analysis technology and discloses a deformation decomposition method for irregular-boundary components based on regular tetrahedron units, comprising the following steps: constructing the spatial deformation of regular tetrahedron units in a spatial rectangular coordinate system based on mathematical orthogonality and mechanical equilibrium to obtain a deformation decomposition basis matrix; establishing a spatial irregular-boundary component model, using regular tetrahedron units to divide any part of the component, obtaining the basic deformation and basic displacement projection coefficient vector of the regular tetrahedron units after any displacement and deformation under any load condition; obtaining the basic deformation information of the regular tetrahedron units under any load condition, distinguishing the main deformation and secondary deformation of the regular tetrahedron units under any load condition, and then realizing the deformation decomposition and deformation performance quantitative analysis of any part of the spatial component. The deformation decomposition method based on regular tetrahedron units of the present invention can be better used for performance quantitative analysis of irregular-boundary components in space.

The invention discloses a high-pressure roller mill wear prediction and service life evaluation method based on DEM-FEM coupling simulation. The method comprises the following steps: constructing a roller mill simplified model through modeling software; the method comprises the following steps: simulating crushing and contact behaviors of grinding material particles based on a discrete element method (DEM), and quantifying interaction between the particles and interaction between the particles and a roller surface by adopting a Hertz-Mindlin contact model and a Tavaries crushing model; analyzing stress and deformation characteristics of a roll shaft structure based on a finite element method (FEM), mapping particle contact force output by discrete elements into a distributed load of a finite element model by utilizing a mechanical equilibrium equation, and solving roll shaft contact stress, strain and plastic deformation distribution; and calculating the instantaneous wear loss based on an Archard wear model, converting the instantaneous wear loss under multiple working conditions into a damage index in combination with a linear cumulative damage theory, and judging the service life of the roller surface when the total damage index reaches a threshold value. According to the invention, accurate prediction of roller surface wear and scientific evaluation of service life under the action of multiple working conditions are realized.

The invention discloses a pressure-bearing under-consolidated stratum anchorage stability calculation method and system, electronic equipment and a storage medium, and the method comprises the steps: S100, constructing a water-soil pressure calculation model considering the influence of under-consolidation and confined water, and calculating the pressure of the confined water in the pressure-bearing under-consolidated stratum; the vertical and horizontal effective soil pressure at any depth z, the pore water pressure and the total pressure are calculated, and finally the water and soil pressure distribution rule is obtained; s200, based on a water and soil pressure distribution rule, accurately calculating force acting on each interface of the anchorage foundation through integral operation; s300, according to a limit equilibrium theory, establishing a mechanical equilibrium equation of the anchorage in the horizontal direction, and deducing an analytical expression of an overall anti-sliding stability coefficient containing all key parameters; and S400, on the basis of the established balance equation, constructing a calculation formula of an anti-skid stability coefficient, and applying the calculation formula to the three core scenes according to different engineering requirements. A water and soil pressure calculation model is constructed, and a mechanical balance system of all stress surfaces of the anchorage is established.

The present application relates to the technical field of wind turbine inspection robot, in particular to a kind of inspection robot negative pressure cavity adsorption force distribution method suitable for wind turbine detection, when inspection robot is operated, the inclination angle of the detection site of wind turbine, i.e. α Satisfy 10°≤ α ≤80°, the yaw angle of inspection robot β Constantly equal to 0;Based on dynamic mechanical equilibrium principle, the real-time dynamic distribution of adsorption force is carried out to the three negative pressure cavities at the bottom of inspection robot, to ensure that the robot can keep stable adsorption when walking inside the blade web of 10°-80°, and improve the safety and working efficiency of inspection robot during fan blade detection operation.

A three-dimensional layered semi-infinite foundation transient heat transfer stress coupling numerical analysis method comprises the steps that a semi-infinite domain is divided into a near-field area and a far-field area, coordinate transformation is established based on geometric similarity between similar surfaces and boundary surfaces, and a proportional boundary finite element coordinate system is formed; deriving a heat conduction and thermal stress control equation under an SBFEM coordinate system based on a variational principle and a virtual work principle, and establishing a dimensionless heat conduction matrix under a frequency domain; solving a heat conduction matrix by adopting a continuous fractional expansion method and Scherr decomposition, and realizing time domain integration through an improved fine time-history integration method (MPTSIM); under a sequential coupling framework, firstly solving a transient temperature field, and then applying the transient temperature field as a thermal load to a mechanical equilibrium equation to obtain a displacement field and a stress field; according to the method, the calculation scale and resource consumption are remarkably reduced while high precision is guaranteed, and the method is suitable for efficient analysis of the transient thermal-mechanical coupling problem in the three-dimensional layered semi-infinite foundation.

The application relates to a natural gas hydrate decomposition process full-coupling numerical simulation method and device, wherein the method comprises the following steps: establishing a mass conservation model, an energy conservation model, a mechanical equilibrium model and a hydrate decomposition model of soil particles, hydrates, gas and water of natural gas hydrates in a decomposition process, constructing a heat-flow-force-chemistry full-coupling model of natural gas hydrates in the decomposition process, taking gas pressure, water pressure, temperature and displacement in different directions as basic unknown quantities of the model, and establishing a finite element weak integral form of the heat-flow-force-chemistry full-coupling model; performing numerical solution on the finite element weak integral form, and assembling a DEHydrate simulator based on a solution result to simulate an evolution trend of reservoir mechanical behavior of natural gas hydrates in the decomposition process. Therefore, the problems that existing hydrate decomposition simulators cannot realize complete coupling among seepage, hydrate phase change, heat transfer and geomechanics are solved.

The invention relates to the technical field of mechanical engineering, and discloses a tooth surface contact stress calculation method for a multistage parallel shaft gear transmission system. Compared with the prior art that the gear surface contact stress is calculated only according to the gear structure, the influence of the system structure flexibility on the gear meshing characteristic is neglected, and consequently the calculation of the gear surface contact stress is inaccurate, the technical scheme is combined with the structural characteristics of the system, and the multi-stage parallel shaft gear transmission system is dispersed into a plurality of basic units; a stiffness matrix of a system is established by calculating a stiffness matrix of each basic unit, then a statics equilibrium equation set of the system is established according to working condition information and a load vector, the meshing misalignment amount of a gear pair is obtained by solving the statics equilibrium equation set of the system, and the tooth surface contact stress is calculated according to the meshing misalignment amount. According to the technical scheme, the influence of a flexible structure on the system is comprehensively considered, and more accurate calculation of the tooth surface contact stress of the multistage parallel shaft gear transmission system, which is more suitable for practical application, is realized.

This invention relates to the fields of vibration control and nonlinear mechanics, and provides a programmable method for generating two-dimensional nonlinear forces. The method includes: responding to a two-dimensional nonlinear force generation request; acquiring the structure and structural parameters of a mechanical realization device; determining the trajectory of the center point of a rolling component during motion based on mechanical equilibrium relationships, and acquiring the geometric expression of the rolling component's trajectory surface; and, based on the geometric dimensions of the rolling component, performing equidistant mapping along the normal direction on the rolling component's trajectory surface, causing the rolling component to adhere to and roll along a three-dimensional guide surface, thereby generating a nonlinear force corresponding to a target nonlinear force function. This method not only generates nonlinear forces of arbitrary continuous form based on a preset target force function and supports personalized customization of nonlinear stiffness characteristics, but also generates nonlinear forces that meet target requirements in two mutually orthogonal motion directions.

This invention discloses a method for evaluating oil saturation based on the self-sealing capacity of tight reservoirs, relating to the field of petroleum exploration and development technology. First, this invention fits an acoustic transit time-depth trend line based on conventional logging data, and uses the Eaton method to calculate the total overpressure and separate hydrocarbon generation pressurization. Second, through high-pressure mercury injection experiments and conversion of charging characteristics, the relationship between pore throat radius and oil saturation is determined. Then, based on the capillary pressure formula and hydrocarbon generation pressurization intensity, the critical charging pore throat radius is determined. Based on mechanical equilibrium relationships, the upper limit of the self-sealing pore throat radius is determined. Finally, the effective reservoir pore throat range is defined, and oil saturation is calculated. This method overcomes the technical shortcomings of traditional methods that neglect the dynamic coupling relationship between hydrocarbon generation pressurization, pore throat charging, and self-sealing capacity during tight oil accumulation, resulting in large evaluation errors.

The present invention relates to the field of ship energy conservation technology, and in particular to a method for calculating the energy conservation effect of a wind-assisted propulsion ship, comprising: setting ideal conditions based on empirical values ​​to obtain iterative initial values; constructing a linear equation system of the generalized secant method based on a four-degree-of-freedom mechanical equilibrium equation system and calculating a weight matrix; weighting the iterative initial values ​​to obtain iterative results; calculating iterative condition parameters and iterating forward; determining the iterative conditions, and continuing the iterative process when the iterative conditions are met, and outputting the first iterative initial value when the iterative conditions are not met. The present invention adapts to the complexity of the equation system expression in the wind-assisted propulsion ship energy conservation effect evaluation model, is easy to use, can avoid the occurrence of ill-conditioned matrices in the iterative process, has fast convergence, and produces accurate results.