189 results about "Stiffness matrix" patented technology

The invention provides a crustal stress prediction method and device, electronic equipment and a storage medium, and relates to the technical field of seismic survey. The method comprises the following steps: obtaining observation seismic data of seismic wavelets in a strong VTI medium, and constructing a to-be-inverted parameter matrix based on a PP wave reflection coefficient corresponding to the strong VTI medium; constructing a posterior probability function obeyed by an inversion parameter matrix corresponding to the to-be-inverted parameter matrix based on a Bayesian inversion theory and observation seismic data, and determining a target functional based on a prior probability function and a likelihood function corresponding to the posterior probability function; determining medium density and each stiffness matrix coefficient based on an inversion parameter matrix solving result of the target functional, and determining a flexibility matrix of the strong VTI medium based on each stiffness matrix coefficient; and predicting the ground stress distribution of the target profile in the strong VTI medium based on the medium density and the positive strain matrix and the flexibility matrix corresponding to the strong VTI. Therefore, the crustal stress prediction accuracy under the strong VTI medium is improved.

The invention discloses an oral cavity finite element simulation calculation method based on collision detection. The method comprises the following steps: 1) acquiring oral scanning data of teeth, generating surface grid data of the invisible appliance according to the oral scanning data, and then generating a tetrahedral grid from the surface grid of the invisible appliance for subsequent simulation calculation; 2) on the basis of collision detection, calculating a pushing vector of teeth to the invisible appliance, and taking the pushing vector as a displacement boundary condition of subsequent calculation; 3) constructing a three-dimensional finite element model taking voxels as units, calculating an element stiffness matrix, assembling an overall stiffness matrix, loading displacement boundary conditions, forming a finite element solution equation set, and obtaining a model node displacement result; and 4) calculating stress and strain of the finite element model according to a displacement result. Aiming at the orthodontic mechanical analysis of the invisible orthodontic appliance, the invention provides a modeling method for the interaction between the teeth and the invisible orthodontic appliance based on a collision detection technology, completes the subsequent simulation solution of a finite element model, and gives consideration to the solution precision and speed.

The invention discloses a bridge anti-fatigue performance analysis and optimization method and system based on finite element analysis. The method comprises the following steps: constructing a bridge finite element basic model and a random fleet time-varying load spectrum, and executing damage-rigidity dynamic coupling iterative calculation; a fatigue sensitive area is automatically identified through the strain energy density gradient, a high-precision sub-model is generated, a basic model stiffness matrix is updated in real time through a sub-model calculation result, and a fatigue evolution cloud picture containing a stiffness degradation track is generated; and finally, identifying a damage hotspot based on the cloud picture, and generating an optimization strategy containing a traffic current limiting threshold and a structure reinforcement opportunity by using a genetic algorithm. According to the method, the problem of prediction deviation of traditional static analysis is solved by simulating the reverse influence of damage on rigidity and internal force redistribution, and accurate evaluation and scientific decision-making of the whole life cycle of the bridge are achieved.

The invention belongs to the technical field of robot cooperative control, and particularly relates to a distributed self-adaptive control method and system for cooperation of multiple mechanical arms, and the method comprises the steps: decoupling a pure internal force vector from the data of a six-dimensional force sensor at the tail end through pre-identified kinetic parameters; calculating a cooperative confrontation index according to the pure internal force vector and the relative position vector, calculating a self-adaptive internal force penalty weight through nonlinear mapping based on the cooperative confrontation index, establishing a state-space equation of the system based on a double-integral model, introducing an equivalent environment stiffness matrix, mapping a prediction error vector in a prediction time domain into a prediction internal force vector, and obtaining a prediction internal force vector; and a cost function containing the product of the self-adaptive internal force penalty weight and the predicted internal force vector is constructed, an optimal control increment sequence is obtained by minimizing the cost function, and a speed instruction is updated to drive the mechanical arm to move. According to the method, the robustness and the execution stability of the system are effectively improved, and the cooperation safety is guaranteed.

The invention discloses a foundation pit supporting structure deformation and internal force calculation method. In the calculation method, an out-pit constraint stiffness matrix is introduced as a calculation factor, and a stiffness coefficient is iteratively calculated; the calculation method comprises the following steps: S1, constructing a foundation pit supporting structure calculation model; s2, a displacement-load total balance equation of the supporting structure under the undetermined supporting working condition of the foundation pit is determined; s3, a servo support is installed, prestress is loaded, a constraint stiffness matrix is introduced, a stiffness coefficient is calculated in an iterative mode, a displacement-load total balance equation of the supporting structure is established step by step, and the deformation condition of the supporting structure is analyzed and calculated; s4-5, the steps S2 to S3 are repeated until installation of all servo supports and prestress loading are completed, and displacement and internal force of the supporting structure are calculated; and S6, the foundation pit continues to be excavated to the pit bottom, deformation and internal force under all working conditions are calculated, and regulation and control calculation can be conducted in the process. By means of the calculation method, accurate calculation of deformation and internal force of the foundation pit supporting structure under the servo supporting effect can be achieved.

The invention is suitable for the field of portal frames, and discloses a portal frame dynamics analysis method which comprises the following steps: establishing a full-order finite element model of a portal frame, and obtaining a mass matrix and a stiffness matrix of the full-order finite element model; dividing the full-order finite element model into a plurality of substructures based on the modular structure characteristics of the portal frame, and decomposing the degree of freedom of each substructure into an internal degree of freedom and a boundary degree of freedom; constructing a fixed boundary main modal matrix and a constraint modal matrix of each substructure, and constructing a reduced-order basis matrix; performing modal polycondensation on a mass matrix and a stiffness matrix of the full-order finite element model by using the reduced-order basis matrix to generate a reduced-order mass matrix and a reduced-order stiffness matrix, and constructing a reduced-order kinetic equation; and solving the reduced-order kinetic equation to obtain reduced-order modal coordinates, carrying out inversion reduction in combination with the reduced-order basis matrix and the reduced-order modal coordinates to obtain a displacement response vector of the full-order finite element model, and retaining key kinetic information of the portal frame to the greatest extent through reduced-order efficiency improvement.

The invention belongs to the technical field of aircraft thin-wall structure design, and particularly relates to a method for correcting a quadrilateral shell unit in aircraft thin-wall structure finite element analysis, which comprises the following steps of: 1, establishing a unit coordinate system for the quadrilateral shell unit; step 2, under the unit coordinate system, establishing an equilibrium equation of a plane stress unit related to in-plane deformation, and calculating a rigidity matrix of the plane stress unit; step 3, under the unit coordinate system, establishing a balance equation of a bending plate unit related to out-of-plane deformation, and calculating a rigidity matrix of the bending plate unit; 4, applying an in-plane rotation penalty term on the rotational stiffness of the quadrilateral shell unit, and calculating the influence of the in-plane rotation penalty term on the strain energy function of the quadrilateral shell unit under the unit coordinate system to obtain an in-plane rotation stiffness matrix; 5, calculating a stiffness matrix of the quadrilateral shell unit under the unit coordinate system; and step 6, coordinate transformation is carried out to obtain a stiffness matrix of the quadrilateral shell unit under the overall coordinate system.

The invention discloses a linear variation stiffness matrix method for suspension bridge space cable forming form finding, relates to the technical field of bridge numerical simulation, and solves the defects of a stiffness matrix in the process of solving the suspension bridge forming form finding through a segmented catenary method. The method comprises the steps that a suspension bridge is simplified into a space cable system composed of a main span, a side span and an anchor span, and the main span, the side span and the anchor span are sequentially subjected to a bridge forming and shape finding process; the linear change stiffness matrix solved in the bridge forming and shape finding process of the main span is used for representing the linear relation between the displacement change of the control point and the initial force change of the main cable; according to the method, an analytical expression of a linear change stiffness matrix is deduced, and an efficient iterative algorithm is established. According to the algorithm, the initial force correction is directly calculated according to the displacement error of the control point in each iteration.

The invention discloses a complex soft foundation waterscape miniature steel pipe pile reinforcing method which comprises the following steps: accurately predicting a deformation value of a potential settlement area by fusing thickness distribution parameters, soil compression modulus and numerical simulation, and comparing the deformation value with an engineering safety threshold. When deformation exceeds the standard, an optimization algorithm is adopted to adjust pile foundation arrangement, optimized pile foundation position parameters are generated, then connection node coordinates are extracted from the bottom plate structure model, and stress transmission efficiency and load distribution uniformity are calculated. And if the uniformity is lower than a threshold value, a reinforcement configuration scheme is finally generated by iteratively updating a connection node stiffness matrix, optimizing connection mechanism parameters, extracting mechanical transmission path data, simulating long-term stability and evaluating the durability improvement degree. According to the method, multi-level parameter optimization and numerical simulation are combined, so that the foundation stability and the load distribution uniformity are ensured, and the engineering durability and safety are remarkably improved.

The invention discloses a structural topology optimization design method for additive manufacturing and a related device, which can be used in the field of structural design, in the method, based on the shape of a structural design domain and a parameterized density field function including the structural design domain, a structural density field is determined, and a suspension angle constraint function at a structural boundary is constructed; constructing a boundary gradient constraint function based on a normal vector pointing to the interior of the structural design domain on the boundary of the structural design domain; discretizing the structural design domain into a plurality of finite element units, and constructing a material stiffness matrix to calculate an overall stiffness matrix; and constructing a topological optimization mathematical model according to the finite element balance constraint, the volume constraint, the suspension angle constraint function and the boundary gradient constraint function based on the overall stiffness matrix, and solving to obtain a structural topological optimization result. Therefore, through multi-constraint collaborative optimization, the conflict problem of suspended constraint and material anisotropy on the forming direction is solved, and a structural topological optimization result considering manufacturability and structural performance is obtained.

The invention relates to the technical field of computer-aided analysis, in particular to a floating foundation structure dynamic response real-time analysis system and method.The system comprises a residual vector calculation module for generating a residual force vector based on a full-order external excitation force vector, an increment base generation module for calculating a modal amplitude and constructing an increment base vector, and an increment base generation module for generating an increment base vector; the reduced-order matrix updating module constructs an enhanced reduced-order model by using the updated projection matrix, and the transient response solving module solves and obtains a corrected generalized coordinate value based on the enhanced reduced-order model and maps the corrected generalized coordinate value into a dynamic displacement field. According to the method, a residual vector is generated by calculating a difference value between full-order external excitation and internal force, residual force is mapped into static deformation distribution by using a stiffness matrix inverse operator, an incremental base is constructed through orthogonalization processing, adaptive updating of a projection space of a reduced-order model is realized, the system dimension is reduced, and the precision is guaranteed. And the calculation efficiency and the real-time performance of dynamic response analysis of the floating structure are improved.

The invention relates to a dam safety state intelligent prediction method and system based on regression modeling, and the method comprises the steps: carrying out the self-adaptive wavelet packet decomposition of structural data collected by a sensor, so as to extract a time sequence feature, and carrying out the differential coding of an environment variable, so as to generate a covariable feature; the method comprises the following steps: mapping a text event into vector features through a knowledge graph, inputting the features into a mixed primary function library formed by a physical primary function and a data primary function, and constructing a sparse regression model through a dynamic gating mechanism; a physical constraint term based on a stiffness matrix and an external load matching error is introduced into the model, a causal graph is dynamically updated through an incremental PC algorithm, and a causal regularization term is added into a loss function to improve the adaptability of the model. The method is suitable for dam structure health monitoring, intelligent early warning, long-term trend analysis and other application scenes, and has good real-time performance, interpretability and small sample generalization ability.

The invention relates to the technical field of cold chain transportation environment control, and discloses a temperature and humidity control system for cold chain transportation, and the system comprises an environment modeling module which is used for constructing a heat conduction model of a cold chain space based on a random field theory and a finite element method, and outputting a stiffness matrix containing random parameters; the self-adaptive sensing network module is used for receiving the characteristic information of the stiffness matrix, dynamically optimizing sensor distribution positions, collecting multi-node temperature and humidity data and adding space-time labels; and the distributed data processing module is used for receiving the sensing data. According to the invention, through random field theoretical modeling and parameter-state joint estimation, the temperature field prediction precision is significantly improved and the system environment adaptability is enhanced; a distributed sensing network architecture and a heterogeneous calculation acceleration technology are combined, so that the cooperative control with optimal energy efficiency is realized while millisecond-level real-time response is ensured, and the performance bottleneck of a traditional cold chain temperature control system is comprehensively broken through.

This invention relates to the field of deep learning technology, specifically to a numerical simulation method for true triaxial tests of coarse-grained soil materials based on principal stress effects. The method includes the following steps: acquiring three-dimensional geological parameters and boundary condition data of the coarse-grained soil material; and constructing a true triaxial finite element simulation model of the coarse-grained soil based on the three-dimensional geological parameters and boundary condition data. This invention utilizes a loading increment step size for trial calculations and calculates the reward function value based on the convergence state and iteration count of the trial calculation results to update the network parameters, enabling the control strategy to continuously evolve through interaction with the environment. This allows for the identification of dangerous regions with highly nonlinear constitutive relations or near-singular stiffness matrices. In these regions, the step size is automatically reduced to ensure computational convergence, while in stable regions, the step size is increased to improve computational efficiency. This solves the problem that traditional fixed step sizes or simple adaptive step sizes easily lead to computational divergence or excessive iterations under complex stress paths.

The application relates to the technical field of square column bearing prediction, and specifically discloses a sea sand and seawater square column bearing prediction method based on dynamic modeling. The environment parameters of the sea sand and seawater square column are acquired by a system to generate an initial non-uniform stiffness matrix and an initial stiffness centroid coordinate. The three-dimensional coordinate displacement data of the section corner point under the incremental load are received, the strain plane equation is obtained through strain plane fitting, and the neutral axis position and the inclination are extracted by solving the equation zero solution. The neutral axis inclination change rate between adjacent load steps is calculated and compared with the preset inclination evolution threshold value: if the threshold value is not exceeded, the section internal force is calculated according to the neutral axis position; if the threshold value is exceeded, the stiffness reorganization cycle is triggered. The cycle is terminated when the trajectory diverges, and the current load step bearing capacity is output as the limit bearing capacity prediction result. The traditional uniform stiffness assumption is broken through, and adaptive evaluation based on the real-time response of the structure is realized.

The application discloses a structure nonlinear deformation reconstruction method and system based on isogeometric and reduced basis, and the method comprises the following steps: measuring initial strain data of a ship plate structure surface, constructing a plurality of four-node inverse shell elements of the ship plate based on the initial strain data; assembling the plurality of four-node inverse shell elements to obtain a whole stiffness matrix; reconstructing the whole stiffness matrix based on the measured strain data of the ship plate to obtain a linear reconstruction result of the ship plate; correcting the linear reconstruction result based on the reduced basis, and fusing the correction increment to the linear reconstruction result for nonlinear iteration to complete nonlinear deformation reconstruction. On the basis of the principle of isogeometric analysis, the application combines the inverse finite element method to establish a four-node inverse shell element, realizes high-precision ship structure displacement reconstruction through a small number of strain measuring points, and helps designers to intuitively understand and deeply understand the mechanical properties of the structure and to monitor the safety of the structure in real time.

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

This invention discloses a method for joint evaluation and optimization of buckling and bending of arbitrary quadrilateral laminates based on physical information neural networks, relating to the field of composite material structure design technology. The method, for arbitrary quadrilateral laminates, first constructs a method based on classical laminate theory... USA The stiffness matrix explicitly reflects the influence of ply parameters, and a physical domain is transformed to a reference domain through a bitriangular affine mapping to establish a physical information neural network mechanical model. The model is trained with the goal of minimizing the total potential energy or Rayleigh quotient, solving for the buckling factor and layer-by-layer strain limits, and adapting to four typical boundary conditions through a boundary embedding function. Subsequently, using ply angle and thickness as variables, optimization is performed using a genetic algorithm, with the goal of minimizing mass, and the buckling factor and strain limits as constraints. The final output is the optimal ply scheme that satisfies specific boundary conditions. This invention can optimize ply angle and thickness while satisfying buckling stability and strain strength constraints.

The present application relates to the technical field of force sensor, disclose a kind of nonlinear decoupling method and system of triaxial force sensor, comprising: acquisition multi-dimensional original data, and carry out adaptive noise reduction, dynamically select wavelet base, construct filter matrix and obtain denoising signal;Dynamic PINN proxy model is constructed, material parameters and environmental variables are fused, and stiffness matrix is output, online parameter updating mechanism is established, and the optimized parameter calculated is constructed enhanced dynamic compensation matrix;The output stiffness matrix and enhanced dynamic compensation matrix are fused and the main singular value is reserved;Reconstruction obtains reconstructed strain field, establishes multi-physical field coupling model compensation quantum-thermal coupling error, and compensates the lead inductance coupling under high frequency;Multi-scale graph structure is constructed, loss function is reinforced by physical constraint, crystal plasticity hysteresis compensation is carried out, multi-scale features are fused, and the decoupling force value is calculated;Establish intelligent calibration decision, predict drift trend and dynamically adjust calibration cycle.

The application discloses a seismic risk evaluation method and system, relates to the technical field of seismic numerical simulation, and receives a three-dimensional geometric model of a gridded fault and sets initial conditions; a simulation operation equation is constructed to solve a shear stress loading rate, a normal stress loading rate and a state variable, and a common differential equation system is constructed; based on the three-dimensional geometric model and the initial conditions, the common differential equation system is used to realize accelerated simulation operation of the shear stress loading rate, the normal stress loading rate and the state variable, wherein the method of the accelerated simulation operation comprises: using a method combining an H-matrix and MPI to accelerate simulation operation, comprising obtaining a layered matrix based on a Green function under a half-space condition in combination with an adaptive cross approximation algorithm, comprising a normal stiffness H-matrix and a shear stiffness H-matrix, and using MPI parallel operation matrix-vector multiplication. The application introduces a hierarchical matrix and fuses an MPI parallel computing framework, so that the simulation period is greatly shortened.

The invention discloses a topological optimization method and device based on a CutFEM and an MMC, a medium and equipment. The method comprises the steps that a design domain is defined, a plurality of initial moving deformation assemblies are arranged in the design domain, and material parameters of the moving deformation assemblies are set; carrying out structured background grid unit division on the design domain; dividing each background grid unit into an entity unit, a blank unit and a cutting unit, and performing sub-grid division on a material area of the cutting unit; identifying boundary lines between the material areas and the material-free areas of the cutting units as inner boundaries and outer boundaries; carrying out stiffness matrix assembly on the material areas of the entity unit and the cutting unit, forming and solving a total stiffness matrix equation, and obtaining node displacement; generating and solving a topological optimization column formula; and calculating the sensitivity, and carrying out iterative optimization. The method can solve the problems that an existing MMC method is low in efficiency and limited in precision under the large-scale complex geometric boundary condition.

The application discloses a material deformation displacement calculation method and a calculation system. The method comprises the following steps: in response to obtained design parameters, a corresponding structure and a geometric model are constructed, and a stiffness matrix K and a load matrix F are generated; the stiffness matrix K is stored in a sparse form by row compression, the load matrix F is input, and a Krylov subspace dimension m, an initial value U0 and an allowable error ε are selected; a set of standard orthogonal bases of the Krylov subspace is constructed; the best approximation U of the displacement in the Krylov subspace is calculated m ; the residual ||F-KU m || is calculated, and if the residual is less than the allowable error ε, the best approximation U m is output as the material deformation displacement; if the residual is greater than the allowable error ε, the best approximation U m is taken as a new initial value, the Krylov subspace is updated, and the material deformation displacement is recalculated. The application provides a stiffness calculation method which can be flexibly deployed and efficiently parallel, and realizes acceleration of finite element analysis.

The invention discloses a gear pair meshing stiffness calculation method considering a thermoelastic coupling effect, which relates to the field of gear transmission, and comprises the following steps: establishing a gear temperature field model and a contact model by utilizing a finite element method, obtaining a gear heat conduction matrix and a structural stiffness matrix, and calculating to obtain gear meshing stiffness and tooth surface load distribution based on an actual tooth surface equation. Calculating tooth surface heat flux density based on tooth surface load distribution, tooth surface friction coefficient and relative sliding speed of each meshing position to obtain a gear thermal load matrix, calculating to obtain an equivalent node load matrix according to a gear heat conduction matrix and the thermal load matrix, and calculating to obtain tooth surface thermal deformation by combining the equivalent node load matrix with a gear structure stiffness matrix. And repeating the steps to obtain the meshing rigidity of the gear pair under the thermoelastic coupling effect. According to the method, the gear contact state iterative solution model based on the potential energy method, the matrix polycondensation method and the slicing thought is established, the requirement for computing equipment is lowered, and the solution efficiency is improved.

The invention discloses a propeller system dynamics analysis method based on a shell unit, and the method comprises the steps: firstly determining the geometric parameters and design conditions of a propeller according to the design task and working condition of an aviation aircraft; and blade chord length distribution and mounting angle distribution are calculated based on an aerodynamic load rule, and an NACA airfoil profile is selected to generate a three-dimensional geometric model. Then, grid division is carried out according to the model, the connection relation between blade nodes and units is established, and a quadrilateral eight-node shell unit grid is formed; a finite element model is established by adopting an isoparametric element theory, a stiffness matrix and a mass matrix are calculated, and then a kinetic equation of the propeller is established. The inherent frequency and vibration mode characteristics of the blade are obtained through modal analysis, and on the basis, aerodynamic loads are applied for dynamic response analysis. According to the method, the parameterized modeling process of the propeller from geometric modeling to kinetic analysis is realized, the aerodynamic coupling vibration characteristics of the blade can be efficiently evaluated, and the method has the advantages of high modeling precision, high analysis efficiency and high adaptability.

The application belongs to the technical field of vehicle structure design, and particularly relates to a high-speed tracked vehicle structure lightweight design method for task reliability, which is based on a dynamics theory model to establish a high-speed tracked vehicle whole-vehicle multi-level mass matrix and a stiffness matrix, generates a whole-vehicle lightweight mass matrix according to a vehicle body and tracked joint lightweight design scheme, calculates lightweight design parameters of each lightweight design scheme for task reliability, determines an optimal lightweight design scheme, calculates modal kinetic energy distribution of the optimal lightweight design scheme, and determines an optimizable stiffness parameter. The application has the advantages of improving modeling efficiency, increasing lightweight design scheme reliability, refining optimizable stiffness parameters, reducing research and development costs, and the like, and can provide an effective high task reliability scheme for high-speed tracked vehicle structure lightweight design.

The invention relates to the technical field of structural material high-performance calculation and numerical simulation, and discloses a metal rubber random vibration damage and fatigue life prediction heterogeneous parallel method which comprises the following steps: inputting finite element model data of a large-scale metal rubber component; a stiffness matrix, a mass matrix and the like are subjected to accelerated calculation by adopting a CPU multi-thread parallel technology, a frequency response function is calculated by combining a multi-process and multi-thread parallel technology, and random vibration response and component fatigue damage based on a frequency domain method are efficiently calculated by utilizing a GPU parallel computing technology. According to the method, a random vibration theory, a frequency domain fatigue analysis method and a finite element calculation method are combined, and meanwhile, multi-process, multi-thread and GPU heterogeneous parallel calculation frameworks are integrated, so that the calculation efficiency is remarkably improved, efficient analysis of random vibration response and fatigue life prediction of the vibration reduction component made of the complex structural material is realized, and the method is suitable for large-scale popularization and application. And an efficient strategy is provided for design optimization and safe service in the fields of aerospace, high-end equipment and the like.

The application discloses a kind of topological optimization method, device, medium and equipment based on CutFEM and SIMP, method includes: definition design domain, discrete design domain into background grid unit, with node density as design variable;Node density is converted into node level value;According to node level value, unit is divided into entity, blank and cutting unit;Subgrid division is carried out to cutting unit;Boundary is identified as inner boundary and outer boundary;Stiffness matrix assembly is carried out to the material area unit of entity unit and cutting unit, obtains node displacement;Solving topological optimization formula, calculating sensitivity updates design variable, until optimal structure is obtained.The application combines CutFEM and SIMP, can solve the problem of insufficient calculation accuracy and efficiency of existing SIMP method under complex geometry and boundary conditions.

The invention discloses a non-local problem adaptive finite element method based on a Cartesian grid, and the method comprises the steps: calculating an element stiffness matrix, and carrying out the data storage in a linear table; calculating the number of non-zero elements in each row of the stiffness matrix according to the topology of the Cartesian grid, and pre-distributing the memory of the total stiffness matrix at one time; according to the result of memory pre-allocation, a correct numerical value is called from the linear table and added to the correct position of the stiffness matrix, and a total stiffness matrix used for solving is obtained; and assembling an algebraic system according to the total stiffness matrix, performing iterative solution in combination with a self-adaptive encryption index given based on posterior error estimation, and outputting a self-adaptive grid generated by iteration and a corresponding solution. According to the method, by pre-calculating possible numerical values of the stiffness matrix and providing efficient and reliable posterior error estimation, acceleration of the assembly process and improvement of the grid quality are achieved.

The invention relates to an anti-deformation leveling algorithm based on a foot-ground contact model and a platform rigidity model. The anti-deformation leveling algorithm comprises the steps that a foot-ground interaction load-settlement model, a platform load-deformation rigidity model and a leveling algorithm with feed-forward compensation are established; a foot-ground interaction load-settlement model is adopted to describe foot-ground contact settlement behaviors, and the landing leg settlement amount is predicted by identifying ground rigidity parameters; secondly, establishing a platform structure stiffness matrix, quantifying a platform load-deformation relationship, performing simulation calculation on a platform system under a typical leveling pose by using a finite element method, and obtaining stiffness coefficient matrixes corresponding to different poses; and finally, designing a leveling algorithm with feed-forward compensation, and superposing the total compensation amount to leveling control output by predicting the landing leg settlement amount and the landing leg structure deformation amount so as to realize feed-forward control. According to the method, the foot-ground contact model and the platform load-deformation rigidity model are constructed, and rapid and stable leveling is realized through a dual-mode control algorithm.

The invention discloses a parameterized propeller modeling method based on a shell unit. The parameterized propeller modeling method is used for optimizing the design of a propulsion system of an aircraft. According to the method, geometric parameters and design conditions of a propeller are determined according to a design task book and working conditions; then, based on aerodynamic load distribution, chord length changes of the blades are calculated, and the torsion rule of the blades is determined according to the inflow angle and the attack angle; furthermore, a proper NACA airfoil profile is selected, and a three-dimensional geometric section of the blade is generated, so that excellent aerodynamic performance is ensured. On the basis, the connection relation between the nodes and the units of the blades is established through grid division, and a shell unit finite element grid is formed. Constructing a shell unit model by adopting an isoparametric element theory, and calculating a stiffness matrix and a mass matrix of the blade; and finally, in combination with material parameters and boundary conditions, establishing a kinetic equation, and performing modal and dynamic response analysis. According to the method, the blade design and analysis efficiency is effectively improved, the structural strength and the vibration characteristic are guaranteed, and a novel propelling solution with economical efficiency and innovativeness is provided for Boeing aircrafts and other types of aircrafts.