73 results about "Energy method" patented technology

The present invention is applicable to the technical field of stability control of distributed drive electric vehicles, and provides a stability analysis and optimization method for distributed drive electric vehicles. The method combines the advantages of the phase plane method and the integral dissipated energy method, projects the integral dissipated energy method onto the phase plane and performs corrections, and determines the final stable domain, pan-stable domain, and unstable domain division forms. The method expands the range of the stable domain and makes the defined stable domain more accurate.

The invention relates to the technical field of tunnel engineering design, and discloses a comprehensive evaluation method and system for longitudinal deformation of a shield tunnel, and the method comprises the steps: obtaining a target shield tunnel analysis calculation parameter; based on the target shield tunnel analytical calculation parameters and the target shield soil analytical calculation parameters, constructing a first shield tunnel stress calculation model to calculate additional stress at the axis of the target shield tunnel; constructing an additional stress work equation at the axis of the target shield tunnel to obtain the total work of the target shield tunnel under stress; constructing a second shield tunnel longitudinal deformation calculation model based on an energy method to obtain a longitudinal displacement field at the axis of the target shield tunnel; constructing a third shield lining performance nonlinear degradation model to obtain an evaluation index of the longitudinal deformation of the target shield tunnel; evaluating the longitudinal deformation of the target shield tunnel based on the evaluation index; the tunnel longitudinal deformation evaluation method solves the problems that an existing tunnel longitudinal deformation evaluation method is single in consideration of influence factors and poor in evaluation accuracy.

The invention discloses an air conditioner energy saving method and device based on a neural network and a genetic algorithm, and the air conditioner energy saving method based on the neural network and the genetic algorithm comprises the steps that S1, data information corresponding to the temperature in a building is obtained; s2, the obtained data information is input into a recurrent neural network model for prediction processing, and the recurrent neural network model outputs predicted indoor temperature and total active power; wherein the recurrent neural network model is obtained by training the historical data information of the building; s3, the predicted indoor temperature and total active power are input into a genetic algorithm module for optimization calculation, and an optimization result is obtained; and S4, whether the obtained optimization result reaches an optimization target or not is judged, and if yes, the optimized indoor set temperature and the optimized air supply temperature are output.

The invention discloses an efficient low-energy-consumption non-oriented silicon steel magnetic performance optimization and production method, and belongs to the technical field of metallurgy. Comprising the following steps: 1) designing components in percentage by mass; (2) the process steps are as follows: smelting and continuous casting; hot rolling; selective normalizing; cooling control; cold rolling and annealing: the total reduction rate is 70%-85%, the annealing adopts a two-stage manner, the front stage adopts a wet atmosphere of 850 + / -10 DEG C, and the rear stage adopts a dry atmosphere of 950 + / -10 DEG C; according to the efficient production method of the non-oriented silicon steel, through component design and process collaborative optimization, the magnetic performance is improved while energy consumption of the normalizing procedure is reduced, and the efficient production method is especially suitable for high-grade products.

The present invention relates to a method and system for predicting the buckling load of scour-damaged bridges based on machine learning, and belongs to the field of machine learning and structural engineering technology. The prediction method includes: raw data acquisition, raw data preprocessing, construction of a LightGBM machine learning model, and evaluation and verification of the constructed model using a variety of performance evaluation indicators. The present invention comprehensively considers key variables such as bridge structural parameters and foundation soil physical properties, constructs a large sample database covering a large number of scour combinations, and utilizes an energy-based buckling analysis method for the pier-cap-pile structure system after scour damage to accurately calculate the critical buckling load of the structure as the output target. Combined with an integrated learning algorithm, a multivariate nonlinear mapping relationship is established to replace traditional complex calculations. It has good engineering adaptability and universality, and can be applied to rapid prediction of buckling bearing capacity under different parameter bridges, different foundation forms and complex scour conditions.

The invention relates to an RPV material small-size sample fracture toughness conversion evaluation method, which comprises the related steps of material fracture toughness testing based on energy method parameters, obtaining of crack initiation driving force energy parameters in a nuclear power structure integrity service state, and nuclear power structure service safety evaluation. The method provided by the invention overcomes the problems that the evaluation of the surface shallow crack is too conservative (the constraint effect of the crack front edge is not considered) and the SIF, J integral and other numerical simulation methods cannot be applied to the unloading process in the existing specification, and can be suitable for the load unloading characteristics of the primary loop of the reactor; and the deep technical support is provided for the long-life safe operation of the RPV of the nuclear power plant.

The invention discloses an electric flywheel hybrid electric vehicle energy management method based on multi-agent deep reinforcement learning, and belongs to the field of new energy commercial vehicle energy management. The invention aims to realize efficient cooperative control among a main driving motor, a control motor and a flywheel by using a multi-agent deep reinforcement learning strategy, reduce the energy consumption of a battery and improve the economical efficiency and the overall performance of a vehicle. The method mainly comprises the following steps: constructing a model of the electric flywheel hybrid electric vehicle; defining six working modes; a multi-agent energy management method is designed, and a state variable, an action variable and a reward function required by a deep reinforcement learning SAC algorithm and a PPO algorithm are set. Under the standard working condition, the multiple agents are trained to obtain the corresponding energy management method, and real-time energy management of the target vehicle is achieved. By applying the multi-agent deep reinforcement learning algorithm to the energy method of the electric flywheel hybrid electric vehicle, the energy consumption of the battery is reduced on the premise of ensuring the performance of the whole vehicle.

The application discloses a kind of wind turbine single blade installation process dynamic response analysis methods considering wind load action, comprising: according to the wind turbine blade installed and construction sea area, establish blade airfoil database and turbulent wind field database;When the position of lifting point and the position of tappet vertex are described, homogeneous transformation matrix is used to describe the motion of each mechanism of ship-mounted crane;When the position of lifting point is described, the position of tappet vertex is described, and the position of blade centroid in space is described by lifting point position, sling length and generalized coordinate;Wind load at each time point in the process of blade installation is obtained;The sling tension in the process of blade installation is obtained;The dynamics model of single blade installation system is established by using Lagrange method;The method can accurately analyze the coupling motion response between crane ship, ship-mounted crane, sling and blade in the installation process, and simultaneously by selecting generalized coordinate and modeling and analyzing the system based on energy method, the system modeling efficiency is effectively improved.

The invention relates to an engine component fatigue life evaluation method based on a structural simulation part, and belongs to the technical field of simulation data processing, and the method comprises the following steps: building a tensile strain energy life prediction model based on elastic strain energy and plastic strain energy, and predicting the fatigue life of a structural part based on the model; optimizing the design parameters of the simulation part of the engine component, manufacturing the simulation part based on the design parameters, performing a low-cycle fatigue test on the simulation part, and analyzing the fatigue life of the simulation part; comparing the fatigue life of the simulation part with the predicted fatigue life of the structural part, and if the requirements are not met, re-optimizing the design parameters of the simulation part; and if the requirement is met, outputting the fatigue life of the structural member. According to the method, the fatigue life of the simulation part is compared with the predicted fatigue life of the structural part, the model is further improved, a closed-loop research method is formed, the accuracy and efficiency of fatigue life prediction are improved, the limitation of a traditional hysteresis energy method is overcome, and the research cost and period are reduced.

The invention discloses a vibration prediction method for a subway superstructure building based on a null space method and an energy method, comprising the following steps: using the energy method to obtain the energy functional of each shear wall and floor slab; obtaining the connection displacement coordination condition matrix between the shear wall and floor slab of each layer of a single-layer and double-layer subway superstructure building under a consolidation connection condition based on the energy functional; obtaining the constraint condition matrix between the shear wall and floor slab of each layer of the single-layer and double-layer subway superstructure building based on the connection displacement coordination condition matrix, using the null space method to solve the constraint condition matrix, constructing the total energy functional of the subway superstructure building and rewriting it into a weight coefficient column vector, scanning the frequency in the weight coefficient column vector, obtaining the displacement response of the subway superstructure building, and then calculating the vibration transmissibility; based on the framework of the energy method, the invention decouples the displacement shape function from the boundary condition, avoids the boundary dependence and other problems in the shape function construction, and then realizes a simple and fast representation of the displacement field of each component of the superstructure building structure.

The invention discloses a power system oscillation traceability analysis method and system based on multi-method probability fusion, which can effectively solve the problem of oscillation source positioning error caused by sparse measurement data and compressed sensing. Firstly, the oscillation source probability of each node is calculated through an oscillation energy method, a frequency spectrum characteristic method, a correlation analysis method, a voltage fluctuation method and a phase angle gradient method; secondly, calculating the adaptive weight of each method based on an information entropy theory, and completing multi-method probability fusion; the fusion probability is optimized in combination with a power grid topological structure, and an oscillation source candidate sequence is determined; and finally, a comprehensive probability distribution diagram and a detailed analysis report are output through a visual module, and reliable technical support is provided for safe and stable operation of a power system.

The present invention discloses a bolt preload evaluation method and a dynamic parameter measurement device thereof, the method comprising: considering constant and dynamic parameters, establishing a bolt preload evaluation model based on the energy method; obtaining the geometric dimensions of the bolted structure, the warping displacement of the measuring point and the parameter data of the physical properties of the material; determining the angular displacement of the thin plate according to the warping displacement of the measuring point and its distance from the axis of the tightening bolt; determining the bolt preload based on the parameter data, the angular displacement and the evaluation model. In addition, the device comprises a measuring point warping displacement and a bolt preload measurement system. The technical solution provided by the present invention can improve the level of structural reliability design by effectively evaluating the bolt preload, provide a theoretical basis for the high-performance assembly of mechanical equipment and the improvement of service performance, and reduce maintenance costs.

The invention discloses a high-overload gyroscope impact resistance design method based on a multi-section trial function energy method, and belongs to the technical field of micro electro mechanical system structure design. Comprising the following steps: constructing a physical model; establishing a trial function; calculating out-of-plane bending flexibility of the novel structural beam; introducing a torsion correction term and an outer frame equivalent flexibility; the flexibility is accumulated, and the reciprocal is taken to obtain the out-of-plane total rigidity; and the out-of-plane rigidity is applied to construction of an impact kinetic equation. A traditional Euler-Bernoulli beam theory cannot effectively consider the influence of rigidity coupling and torsional deformation of multiple sections of beams and the rigidity of an outer frame on the overall rigidity of a structure. According to the method, the out-of-plane equivalent stiffness of the novel structural beam and outer frame combined structure can be quickly estimated and obtained, the obtained stiffness parameter is applied to dynamic characteristic analysis of the gyroscope, and effective theoretical support is provided for design and engineering application of the novel structural beam structure of the high-overload gyroscope in the out-of-plane direction.

The application relates to the motor technical field and is a method for changing the slot torque of a permanent magnet synchronous motor. First, a slot torque expression based on an energy method is established, and a distribution function relationship expression before and after the change of the air gap length is derived; second, a motor model is established, the tooth crest height is changed, the air gap length is increased, and the slot torque is weakened; finally, the air gap length of the motor is further optimized through arc cutting of the tooth tip, and the slot torque is further weakened. Since the motor also affects other performances during optimization, the output torque and loss before and after optimization are compared and analyzed, the output torque is reduced, the loss is increased by less than 0.5%, and the efficiency and power of the motor are ensured.

The present invention discloses an energy management method for an electric flywheel hybrid vehicle based on multi-agent deep reinforcement learning, which belongs to the field of energy management for new energy commercial vehicles. The purpose of the present invention is to use a multi-agent deep reinforcement learning strategy to achieve efficient coordinated control between the main drive motor, the control motor and the flywheel, reduce battery energy consumption, and improve the economy and overall performance of the vehicle. The present invention mainly includes: constructing a model of an electric flywheel hybrid vehicle; defining six working modes; designing a multi-agent energy management method, and setting the state variables, action variables and reward functions required by the deep reinforcement learning SAC algorithm and PPO algorithm. Under standard working conditions, the multi-agent is trained to obtain the corresponding energy management method to achieve real-time energy management of the target vehicle. By applying the multi-agent deep reinforcement learning algorithm to the energy method of an electric flywheel hybrid vehicle, the battery energy consumption is reduced while ensuring the performance of the entire vehicle.

The present application relates to the field of tunnel engineering, and specifically discloses a method and system for fine prediction of rock burst grade in tunnel construction stage by drill and blast method, comprising the following steps: constructing a basic sample library; establishing a mapping relationship between drilling parameters and first principal stress, second principal stress, third principal stress, elastic modulus and Poisson's ratio and other surrounding rock mechanical parameters based on energy method; constructing an extended sample library based on the mapping relationship and the basic sample library; constructing an intelligent rock burst grade prediction model based on deep learning, and bringing the extended sample library into the intelligent rock burst grade prediction model for training; and fine prediction of rock burst grade in front of the tunnel face according to the constructed intelligent rock burst grade prediction model. The present application can effectively reduce the input of construction personnel and prevent the impact of rock burst on the safety of construction personnel, and guide the intelligent construction of tunnels.

This invention belongs to the field of dynamic modeling of vacuum manipulators, specifically a rigid-flexible coupling modeling and analysis method for vacuum manipulators. The method includes: using a rigid body model to describe the arm and a string model from the continuum domain to describe the steel strip. The rigid body is a finite-degree-of-freedom system, while the continuum is an infinite-degree-of-freedom system. A global space discretization method is used to discretize the infinite-degree-of-freedom system into a finite-degree-of-freedom system. Then, the two finite-degree-of-freedom systems are systematically integrated to obtain the rigid-flexible coupling dynamic equations of the vacuum manipulator. This invention establishes a system dynamic model based on the energy method, with a clear approach, and provides a good solution for dynamic modeling of rigid-flexible coupling systems. It solves the problem that vacuum manipulators lack end-point real-time sensing and cannot perceive the system state in real time to provide state feedback for control.

The application aims to provide an improved method for considering the lateral stiffness and the corner stiffness of the spline coupling with misalignment, comprising the following steps: establishing a schematic diagram of the load and deformation of the misaligned spline coupling, deducing the load and deformation balance equation of the misaligned spline engagement state according to the deformation geometry of the misaligned spline; deducing the single-tooth engagement stiffness according to the energy method, correcting the gear tooth engagement stiffness; bringing the single-tooth engagement stiffness of the spline obtained in step (2) into the engagement force balance equation obtained in step (1), and calculating the lateral stiffness and the corner stiffness of the misaligned spline coupling. Through comparison with the finite element results, the calculation results of the application are more efficient, and the vacancy of the calculation method of the lateral stiffness and the corner stiffness of the spline coupling under the misalignment condition at the present stage is made up.

The present invention belongs to the field of wind farm grid-connected control, and specifically relates to a method for efficiently distributing active power of a wind farm taking into account the degree of fatigue damage of wind turbines, aiming to solve the problem that the traditional method evenly distributes the dispatching command power to all wind turbines without considering the influence of power regulation on fatigue damage of wind turbines, which leads to an increase in the probability of wind turbine failure. The present invention includes: wind turbine load estimation based on force analysis and energy conservation, low-complexity fatigue damage quantification based on improved energy method, and a multi-objective optimization model based on Gulin method, entropy weight method and improved matter-element extension model with the goal of minimizing the total fatigue load of the wind farm and the most uniform distribution of fatigue loads between wind turbines. The present invention realizes fast and accurate power distribution, enables wind turbines to operate in a suitable state, reduces the accumulation of fatigue damage and the risk of failure, and improves the overall operating efficiency and economic benefits of the wind farm.

The application provides a distributed line selection and positioning method, which synchronously and high-speed collects zero sequence voltage, zero sequence current and / or three-phase current on each power supply section, carries out zero sequence transient energy method and / or three-phase current transient correlation method analysis, determines a grounding line and positions a grounding fault section; each power supply section on the grounding line is differentially delayed and tripped by a power receiving end phase power supply end, when the fault section is tripped and the fault disappears, all power supply sections before the fault section stop timing, after the fault section isolation time reaches, the power supply of the fault section is restored through reclosing, if the fault is a transient fault, the power supply of the line on the fault section can be restored; if the fault is a permanent fault, the fault section is removed again through post-acceleration, and the permanent isolation of the fault is realized. The application realizes accurate positioning and reliable isolation of a single-phase grounding fault section, guarantees the reliability and safety of power supply, and improves the stability of power distribution network operation.

The invention relates to the technical field of stator blade vibration reduction design, and discloses a stator blade equivalent friction damping ratio calculation method, system and device and a medium. The method comprises the steps that the maximum vibration displacement position on a stator blade in a spring constraint model is obtained; single-point circumferential excitation force is applied to the maximum vibration displacement position through a simulation technology to obtain maximum single-point excitation force, spring displacement and excitation point displacement; the total friction energy consumption of the spring connection position is calculated according to the spring displacement, and the excitation energy is calculated according to the excitation point displacement and the maximum single-point excitation force; and obtaining a current damping ratio according to the excitation energy and the total friction energy consumption, and calculating a difference value between the current damping ratio and the initial damping ratio to obtain an equivalent friction damping ratio. The method is a finite element simulation calculation method for obtaining the equivalent friction damping ratio based on an energy method, and the damping ratio of a margin plate installation structure to a stator blade structure can be evaluated.

The invention provides a rapid prediction method for high-temperature yield strength of an orthotropic metal material. The method comprises the following steps: establishing an expression of material distortion energy density based on an equivalent energy method; deducing a specific expression of distortion energy density based on a stress-strain component by considering a uniaxial tensile stress state and orthoanisotropy of the material; calculating to obtain a key constant value under a uniaxial tensile stress state and a material melting temperature; and finally, deriving a high-temperature yield strength expression of the material in different directions. According to the method, a small number of parameters such as the elastic constant and the specific heat capacity which can be quickly obtained through table look-up are used as input, the yield strength values of the orthotropic material at different temperatures can be quickly predicted, and high cost caused by high-temperature tests of a large number of materials can be avoided; and a fast and efficient yield strength prediction mode is provided for material high-temperature performance prediction and structure high-temperature strength check in practical engineering.

The invention discloses a bamboo grating sandwich panel and a bearing capacity calculation method thereof, and the method comprises the steps: calculating the local buckling bearing capacity of a solid sandwich panel component based on an energy method, and calculating the elastic modulus and shear modulus of a core body through an equivalent method; a correction coefficient related to the length-width ratio is introduced in combination with the orthotropic property of the panel material and the influence of the length on the local buckling bearing capacity, and a local buckling bearing capacity calculation formula is obtained through derivation; according to the method for calculating the overall buckling bearing capacity of the compression component based on the Euler buckling formula, the influence of shear deformation of a core body and orthotropic anisotropy of a panel material are comprehensively considered, and a calculation formula of the overall buckling bearing capacity of the bamboo grating sandwich panel under the in-plane axis compression effect is established. According to the method, stress characteristics and failure modes of the bamboo grating sandwich boards with different lengths under the in-plane axial pressure effect can be analyzed, and certain theoretical guidance is provided for research and application of the bamboo grating sandwich boards.

The invention relates to the technical field of computational fluid mechanics and aeroelastic flutter calculation, and particularly discloses an aerofoil flutter calculation method based on an energy method.The aerofoil flutter calculation method comprises the steps that CFD grids and structural modal data of flow field calculation are prepared, and pretreatment such as modal interpolation is carried out; giving a generalized displacement motion law of a certain order mode, and setting other modes as coupling calculation; starting unsteady flow field calculation; for a mode with a given motion law, calculating generalized coordinates directly according to a motion law expression; for a coupling calculation mode, a generalized coordinate is obtained by solving a structural motion equation; according to the generalized coordinates, updating the grid through a dynamic grid method; solving the flow field and the structural deformation at the next moment in a loop iteration manner until the calculation is finished; according to the calculated generalized coordinates and the generalized aerodynamic force time history, work done by aerodynamic force in one period is calculated, and whether flutter occurs or not is judged according to whether the aerodynamic force does positive work or not. According to the airfoil flutter calculation method based on the energy method, the maximum vibration amplitude of the airfoil in fluid-structure interaction calculation can be manually controlled, the failure of a dynamic grid under large deformation can be avoided, and the calculation stability is improved; the aerodynamic force nonlinearity in flutter can be simulated; frequent fluid-solid data exchange is not needed, and the calculation efficiency is improved.

The present invention relates to the technical field of permanent magnet motors, and provides a modeling and parameter optimization method and system for a hybrid pole sinusoidal permanent magnet motor. The analytical modeling method includes calculating the no-slot air-gap flux density of the motor under no-load conditions of the motor permanent magnet assembly with different remanences and different sector angles according to the remanence distribution of the motor permanent magnet assembly and the air-gap magnetic field boundary conditions; establishing a relationship between the relative air-gap permeability and the slot opening under no-load conditions according to the stator slot model of the motor, and obtaining the relative air-gap permeability with slots through Fourier decomposition calculation; calculating the air-gap flux density with slots of the motor under no-load conditions in the complex coordinate system according to the no-slot air-gap flux density and the relative air-gap permeability with slots; calculating the cogging torque of the motor by the energy method based on the air-gap flux density with slots of the motor under no-load conditions; at the same time, calculating the no-load back electromotive force of the motor according to the winding distribution and the air-gap flux density with slots, and calculating the output torque by combining the no-load back electromotive force of the motor with the actual driving current to obtain the average torque, torque ripple and torque cost.

A phase control technology-based overvoltage suppression method, apparatus and device, and a storage medium, the method comprising: according to a preset iterative symplectic geometric mode decomposition-difference Hilbert transform model, obtaining transient characteristics from a collected voltage signal; determining a stable zero crossing point according to the transient characteristics; in a preset period of the stable zero crossing point, voltage values and current values at all moments before and after the stable zero crossing point are obtained; according to the voltage value and the current value at each moment before and after the stable zero crossing point, and a preset capacitance value and a preset inductance value, respectively calculating an energy sudden change value at each moment; and determining a minimum energy abrupt change value from the energy abrupt change values of the moments according to a minimum energy method, determining the moment corresponding to the minimum energy abrupt change value as a target moment, and controlling the switch to be switched on so as to suppress overvoltage, thereby solving the problems of large stable zero crossing point detection error, uncertain switch switching-on moment and poor stability in the prior art. And the overvoltage suppression effect is not good.

The invention belongs to the technical field of planet rock mechanics, and provides a multi-scale method for calculating probability distribution of planet rock mechanical properties. On the basis of a rock sample, a probability distribution function of planet rock micromechanics parameters is obtained through a rock micromechanics test and a reliability principle; on the basis of the reliability principle, a probability distribution function of the precise elastic modulus of the planet rock is obtained in combination with a precise crystal model and an elastic modulus upscaling method; on the basis of a reliability principle, an energy method, a fracture toughness upscaling method based on nanoindentation and mechanical property correlation are combined, and a probability distribution function of fracture toughness, tensile strength and compressive strength of the planet rock is obtained; based on the mineral image, deep learning and the macro-mechanical property of the planetary rock, constructing a prediction model of the macro-mechanical property of the planetary rock; establishing a planet rock discrete element model; based on an accurate planet rock-soil discrete element drilling and planet exploration vehicle walking simulation model, an evaluation method for researching rock-mechanical mechanics interaction and the like are researched.

The invention relates to the technical field of ocean energy utilization, and discloses an offshore salinity gradient energy power generation system, method and equipment, which combines a vapor pressure difference power generation technology and a microbial desalination and desalination technology, and takes the vapor pressure difference power generation technology as the technical core of the offshore salinity gradient energy power generation system. Fresh water supply required by vapor pressure difference power generation is provided in the desalination process by using a microbial desalination technology, a conventional seawater desalination device is replaced, the energy consumption of seawater desalination treatment is reduced, the requirement of a vapor pressure energy method power generation technology on a geographic position is also reduced, and the power generation efficiency is improved. An existing salinity gradient energy power generation system gets rid of application limitation of river estuaries, efficient application on the sea is achieved, and the application scene is expanded; and electricity can be synchronously generated in the desalination and desalination process, so that the energy consumption of the system is reduced, the overall power density and the power generation efficiency are further improved, and the preparation and maintenance cost of the device is reduced.

The present invention discloses a method for calculating the maximum depth of casing drilling based on an energy method, which relates to the field of rock and soil drilling engineering. This method can effectively determine the maximum depth of casing drilling with a down-the-hole hammer. This method adopts the material mechanics energy method theory. When the casing is drilled to the maximum depth, all the impact energy is used to overcome the formation friction, and the formation friction is manifested as a change in the strain energy of the casing. Secondly, the energy method theory is used to propose hypothetical conditions for the conversion of impact energy and casing strain energy when the casing is drilled to the maximum depth. Then, the formation friction resistance is determined based on the contact mode and relative motion mode between the formation and the casing. Both strain energy and impact energy are incremental parameters at a certain moment, without considering parameters such as drilling pressure, torque, buoyancy, and casing deadweight. Only inherent parameters such as casing size and material, dynamic friction between the formation and casing, and rated impact energy of the impactor are involved. This method can eliminate interference from other parameters and greatly improve the reliability of the calculation results.

The invention discloses a method and a system for designing a multi-stage side slope composite retaining structure, aiming at optimizing the design of the retaining structure of a side slope by considering the action of expansive soil. The method disclosed by the invention comprises the following steps: determining the group number of the retaining structures according to the height of the slope, wherein the group number is greater than or equal to 2; wherein at least one retaining structure comprises an anchor rod frame beam and a sheet-pile wall; under the condition that the side slope is not supported, an equation that the sum of gravity external power and expansive soil external power is equal to internal loss power is constructed, and according to an upper limit method for solving a side slope safety coefficient in the equation and basic parameters of a soil body, slip crack surface parameters of the side slope corresponding to the supporting structure at a given critical height are solved; and according to the solved slip crack surface parameters, a load equivalent method and an energy method, the anchor rod tension, the post-pile pressure and the internal force of the inter-pile plate are calculated, and therefore the anchor rod distance of the supporting and retaining structure, the section size of the slide-resistant pile and the inter-pile plate and reinforcing bars are designed.