46 results about "Linear elasticity" patented technology

The invention relates to the technical field of petroleum and natural gas drilling engineering, and particularly discloses a multi-field coupled complex fractured formation fracture width distribution inversion method, which is characterized in that a drilling fluid leakage model considering a fluid-solid coupling effect is constructed based on a porous elastic mechanics theory, and a roughness correction factor is introduced to correct a traditional cubic law; the application of the Darcy law in the matrix is perfected, a matrix and crack coupled drilling fluid leakage mathematical model is established, the influence rule of key parameters such as fluid viscosity, pressure difference and crack width on the drilling fluid leakage amount is obtained through numerical simulation, and on the basis, the drilling fluid leakage amount is calculated. According to the method, the crack width multiple linear regression inversion equation with the fluid viscosity, the pressure difference and the accumulated leakage as independent variables is established, the inversion equation has high prediction precision and practicability and can be used for rapidly and accurately inversing the crack width on site, and theoretical and technical supports are provided for multi-scale fractured formation leakage mechanism understanding and leakage prevention and control optimization.

The invention discloses a stay cable analysis digital twinborn model construction method, which comprises the following steps of: constructing a stay cable space three-dimensional vibration motion partial differential equation based on a material linear elasticity hypothesis and a double-coordinate system theory, and setting boundary conditions and initial conditions of the stay cable space three-dimensional vibration motion partial differential equation; a Galerkin multi-mode truncation method is adopted to obtain a displacement function of superposition of an end displacement excitation item and a vibration mode item; deducing a three-way strong coupling ordinary differential equation set through symbolic operation, and solving by using a step-variable Runge-Kutta algorithm to obtain a stay cable analysis digital twin model with stable parameters; structural response data are obtained through the sensor network and calculated, and when the obtained cable force, flexural rigidity and damping ratio exceed threshold values, a model updating mechanism is triggered for updating; and then the updated stay cable analysis digital twin model is obtained. According to the method, the real dynamic characteristics of the stay cable can be restored with high precision, and effective support is provided for structural state evaluation and early warning.

The application provides a method, system, medium and device for pipeline configuration in ocean current, which comprehensively considers the stratification effect of ocean current by establishing a stratified flow field, can accurately simulate the movement of fluid around the pipeline, and thus more truly reflects the interaction between the fluid and the pipeline. Meanwhile, the boundary source term is calculated according to the relationship between the fluid velocity on the surface of the pipeline and the displacement of the pipeline surface, so that the boundary source term can accurately represent the fluid reaction force caused by the movement of the pipeline surface. The nonlinear elastic deformation model of the pipeline under the deformation condition is constructed, which can well represent the stress tensor of the pipeline. Finally, the immersed boundary method is used to take the boundary source term as the pipeline surface force, which can handle the fluid and solid interaction problem under complex boundary conditions. Through iterative updating of the flow velocity and the displacement of the pipeline surface, the convergence of the pipeline elastic mechanics equation is obtained, which provides an important reference for the design, installation and maintenance of the pipeline configuration process.

The application discloses a construction method of an elastic mechanics equilibrium equation based on nonlinear strain and an electronic device, and the method comprises the following steps: defining new nonlinear strain tensor components according to the displacement of an elastic body in three directions caused by external force; obtaining a nonlinear strain tensor based on the nonlinear strain tensor components; calculating a stress tensor based on an elastic mechanics constitutive relation and the nonlinear strain tensor; determining new boundary variables, constructing new boundary conditions according to the new boundary variables, and obtaining the elastic mechanics equilibrium equation after deformation according to the stress tensor. The application defines new nonlinear strain tensors and corresponding stress tensors, can perform stress calculation on applications requiring calculation of the stress of the elastic body, the calculation method is simple and clear, and it is found through verification that the nonlinear strain obtained by the application is basically the same as the strain result obtained by the Green strain in the prior art, and therefore the strain defined by the application is reasonable.

This invention relates to the field of shape memory alloy technology, specifically providing a zero-hysteresis giant linear elastic Ni-Fe-Ga shape memory alloy microwire and its preparation method. The preparation method of the alloy microwire includes: ① preparing austenitic alloy microwires using a glass coating method; ② inducing the austenite in the microwires into a full martensite structure through stress aging treatment and maintaining it at room temperature; ③ finally introducing some austenite into the martensite alloy microwires through annealing treatment, obtaining a wire material with a stable austenite / martensite coexistence structure at room temperature. The Ni-Fe-Ga ternary shape memory alloy microwires provided by this invention exhibit both zero hysteresis and giant linear elasticity characteristics under external force, with a maximum elastic strain of up to 7.7%, and the preparation method is simple, showing broad application prospects in high-precision micro-actuators and sensing fields.

The embodiment of the invention provides a material identification method and device, electronic equipment and a readable storage medium, and the method comprises the steps: obtaining an elastic mechanical parameter and a non-elastic mechanical parameter of a target material according to a nanoindentation technology; wherein the elastic mechanical parameters comprise the elastic modulus and the hardness, and the inelastic mechanical parameters comprise the fracture toughness and the creep parameter; analyzing the elastic mechanical parameters and the inelastic mechanical parameters by adopting a statistical deconvolution method to obtain different corresponding mechanical parameters in the target material; and respectively confirming the types of different phases according to the mechanical parameters. According to the method, the elastic mechanical parameters and the inelastic mechanical parameters are collected at the same time to comprehensively analyze the material, analysis and recognition of different phases in the material can be more accurate, and the user experience is improved.

The application discloses a kind of compressed air energy storage cavern operating pressure determination method, comprising the following steps: establishing the elastic mechanics plane strain model of surrounding rock-lining-sealing layer composite structure, deducing the analytical solution of elastic stress and displacement of composite structure;Determine the upper limit of cyclic internal pressure;Introduce the spatial heterogeneity function of surrounding rock parameter, deduce the elastoplastic stress and plastic zone radius expression of composite structure;Introduce the fatigue damage evolution equation to correct rock mass strength parameter, based on the plastic zone radius control condition, solve lower limit pressure.The method can simultaneously utilize initial geostress to constrain surrounding rock deformation and quantify the attenuation of rock mass parameters caused by long-term cyclic loading, while ensuring that surrounding rock does not produce tensile failure and the expansion of plastic zone is controllable, the best operating pressure range and amplitude of compressed air energy storage cavern in the whole life cycle of up to 30 years are accurately quantified, so as to ensure the long-term sealing and safety of the structure, effectively optimize the design parameters, and improve the engineering economy.

This invention discloses a control method for a forklift telescopic boom, which includes a primary boom, a secondary boom, a tertiary boom, and a quaternary boom arranged nested from the inside out; it also includes: a drive cylinder, the cylinder body of which is hinged to the outside of the primary boom, and the piston rod of which is hinged to the secondary boom; a first sprocket and a first chain, the first sprocket being mounted outside the secondary boom; one end of the first chain being fixed to the head of the primary boom and the other end being fixed to the tail of the tertiary boom; this invention overcomes the limitations of traditional length calculations that rely solely on geometric ratios, and innovatively introduces an elastic correction model that includes linear elasticity coefficients and gravity gain coefficients, which can dynamically calculate the elastic elongation of the chain caused by gravity and angle changes based on the real-time piston rod stroke and luffing angle. This allows the control system to obtain boom length data closer to physical reality under dangerous working conditions with high luffing angles and long extensions.

The invention relates to a nonlinear structure reduced-order model construction method based on sparse recognition and a mixed mode, belongs to the technical field of structural dynamics analysis and aeroelastic mechanics analysis, and solves the problem that complex motion caused by geometric nonlinearity under large deformation cannot be accurately described in the prior art. Comprising the following steps: S1, establishing a nonlinear finite element model of a target large flexible wing to obtain a training data set; s2, solving a mixed modal basis based on the displacement residual error and SVD (Singular Value Decomposition); s3, establishing a nonlinear stiffness coefficient solving problem model, introducing LASSO regression to establish an LASSO regression optimization objective function, and solving to obtain a sparse nonlinear stiffness coefficient; s4, based on the sparse nonlinear stiffness coefficient and the structural kinetic equation, establishing a nonlinear structure reduced-order model; and S5, applying the nonlinear structure reduced-order model to statics response solution and dynamics response solution of the large flexible wing to obtain statics response and dynamics response results.

The invention provides a woven composite material multi-scale analysis method based on clustering order reduction, and belongs to the technical field of composite material multi-scale damage evolution evaluation. The method comprises the following steps: 1, defining a microscopic damage constitutive model; defining a fiber damage constitutive equation and a matrix damage constitutive equation; 2, solving an RVE damage problem by using an SCA method; the method comprises the following steps: for a composite material RVE region, converting a control equation of elastic mechanics into a solving L-S equation by introducing reference stiffness; the SCA method comprises an offline stage and an online stage. Step 3, establishing an FE-SCA2 concurrent three-scale model; and the numerical value is solved. According to the method, the problem of low three-scale calculation efficiency is relieved while nonlinear calculation high precision is achieved, and the method has high application value in the field of composite material structure multi-scale calculation.

The application belongs to the field of bridge health monitoring and rapid detection, and discloses a bridge bending stiffness identification method based on multi-point deflection influence line input, and steps are as follows: firstly, a linear model for solving bending stiffness is established by using measured deflection influence lines at multiple positions of a bridge and linear elasticity theory; then, a redundant dictionary composed of multiple types of global basis functions is used for sparse representation of the bending stiffness distribution curve, and the bending stiffness reconstruction problem is converted into a sparse vector solving problem; finally, a sparse vector solution model with 1-norm regularization constraint is established, and the optimal bending stiffness distribution is obtained by solving the model. l The application can realize continuous bending stiffness curve solving by using multi-point measured deflection influence lines only, is suitable for stiffness evaluation of statically indeterminate in-service bridges such as continuous girder bridges, and has the advantages of strong applicability, high solving efficiency and strong robustness.

The invention discloses a structure, a design and a construction method for reinforcing a PCCP (prestressed concrete cylinder pipe) by an internally-wound steel bar composite flexible impermeable layer, a bearing main body of the composite structure is a spiral steel bar on the inner wall of the PCCP, and an impermeable system comprises quick-setting elastic putty between the steel bars and a high-strength flexible impermeable coating on the surface of the quick-setting elastic putty. The design method is based on elastic mechanics, a nonlinear analysis model is constructed, and the design of the steel bar diameter and the screw pitch is achieved. The reinforcing process comprises the steps of spirally winding the steel bars, coating the adhesive, filling the quick-setting elastic putty and blade-coating the high-strength flexible anti-seepage coating, so that a composite anti-seepage reinforcing system with structural strength and deformation adaptability can be formed. The problem that the device enters a narrow space is solved through disassembly and on-site assembly of the steel bar winding device, the technology has the advantages of being good in reinforcing effect, short in construction period and low in manufacturing cost, earth surface excavation is avoided, and the method is suitable for permanent repair of the large-diameter and high-internal-pressure PCCP.

The invention provides a hard rock elastic mechanical parameter obtaining method and device under the eccentric loading condition, and belongs to the technical field of optical measurement and numerical simulation. The method comprises the steps that first displacement is obtained through a uniaxial loading experiment; introducing an eccentric loading coefficient, and calculating in finite element software to obtain a second displacement; establishing a multi-target error function according to the first displacement and the second displacement; outputting the final elastic modulus, Poisson's ratio and eccentric loading coefficient under the condition that the multi-target error function reaches the convergence condition; under the condition that the multi-objective error function does not reach a convergence condition, iteratively optimizing mechanical parameters by adopting a simulated annealing particle swarm optimization algorithm improved by a dynamic cooling strategy based on particle swarm diversity, and incorporating an eccentric loading coefficient into a to-be-inverted parameter; according to the method, the inversion analysis of the rock elastic mechanical parameters and the eccentric loading coefficient is realized, and the inversion precision is improved by adopting the improved simulated annealing algorithm.

According to the pipeline configuration method, system, medium and equipment in the ocean current, the layered flow velocity field is established, the layering effect of the ocean current is comprehensively considered, movement of fluid around the pipeline can be accurately simulated, and therefore interaction between the fluid and the pipeline can be reflected more truly. Meanwhile, the boundary source item is calculated according to the relation between the pipeline surface fluid velocity and the pipeline surface displacement, so that the boundary source item can accurately represent the fluid reaction force caused by the pipeline surface movement. A nonlinear elastic deformation model of the pipeline under the deformation condition is constructed, and the stress tensor of the pipeline can be well represented. And finally, taking a boundary source item as a pipeline surface force by utilizing an immersed boundary method, so that the problem of interaction between fluid and solid under a complex boundary condition can be solved. The flow velocity and the pipeline surface displacement are updated through iteration until the pipeline elastic mechanical equation converges, and an important reference basis is provided for configuration processes such as design, installation and maintenance of the pipeline.

The application provides a corrugated box finite element modeling method for simulating package falling, comprising the following steps: S1: determining equivalent elastic mechanics parameters of corrugated paperboard; S2: verifying whether the equivalent plate anisotropic elastic mechanics parameters are accurate, and if yes, entering S3, otherwise, returning to S1 until the equivalent plate anisotropic elastic mechanics parameters pass the verification; S3: establishing a paper box geometric model, decomposing the paper box into six surfaces of upper, lower, left, right, front and back, modeling each surface by adopting a shell element, and setting topology sharing; S4: respectively giving each surface of the paper box corresponding material properties; S5: dividing the paper box grid model by adopting a quadrilateral, and completing contact setting of the paper box and other PART, setting boundary conditions and load, and solving setting. The method solves the problem that the simulation calculation result of the package falling is not accurate and reliable due to the modeling error of the paper box by combining mechanical test and theoretical formula.

The invention discloses a method for rapidly predicting the elastic-plastic mechanical property of a one-dimensional periodic spiral winding structure, and relates to the technical field of spiral winding structure mechanical property prediction. Comprising the following steps: S1, constructing a finite element model of a one-dimensional periodic spiral winding structure, performing linear elasticity analysis on the finite element model, and extracting a strain concentration tensor; s2, based on the extracted strain concentration tensor, clustering the finite element model by using a clustering algorithm to obtain a reduced-order model after partitioning, and calculating an interaction matrix representing a mechanical relationship between blocks in the reduced-order model; and S3, inputting the interaction matrix into an online incremental algorithm to obtain an elastic-plastic stress-strain curve of the one-dimensional periodic spiral winding structure, and realizing prediction of the elastic-plastic mechanical property of the one-dimensional periodic spiral winding structure. According to the method, the elastic-plastic mechanical property of the one-dimensional periodic spiral winding structure can be efficiently and accurately predicted, and the analysis efficiency and optimization efficiency of the one-dimensional periodic spiral winding structure are improved.

The invention provides a finite element grid rapid reconstruction method based on linear elastic mechanics, which comprises the following steps of: after all node displacement vectors are obtained, superposing all node displacement vectors to all corresponding node coordinates before deformation to obtain all node coordinates after deformation: in the formula, the node coordinates after deformation and the node coordinates before deformation are shown in the description; keeping the corresponding relation between the units and the node numbers unchanged, and modifying node coordinates in the finite element solving file to complete finite element grid reconstruction; calculating a Jacobian determinant, a length-width ratio and a warping factor index of the reconstructed grid, and judging whether Jacobian determinants gt of all units are reconstructed or not; 0.5, the length-width ratio is lt; 5, a warping factor lt; and when 6.5, if yes, determining that the finite element mesh meets the use requirement. According to the method, a physical and geometric dual-drive grid deformation mechanism is established, global displacement distribution is restrained through a linear elastic mechanical constitutive equation, deformation of non-reasonable units is restrained, and the problem of unreasonable topology caused by a traditional geometric interpolation method is solved.

The present invention relates to the field of aeroelastic mechanics analysis, and in particular to a method for analyzing the aeroelastic stability and dynamic response of a rigid-elastic coupling of an aircraft. The method comprises the following steps: determining the inherent shape parameters of the aircraft, dividing the mid-camber surface of the aircraft wing into a plurality of quadrilateral aerodynamic grids along the chord direction and the span direction; establishing a vortex grid method state-space equation based on the aerodynamic grid; establishing a flight dynamics model and a finite element structural model of the aircraft wing, and then establishing a rigid-elastic coupling dynamic equation; utilizing a three-dimensional spline interpolation method to obtain a rigid body motion-structure-aerodynamic coupling relationship, and determining the state-space equation of a generalized external force and a rigid-elastic coupling aeroelastic system based on the rigid body motion-structure-aerodynamic coupling relationship and the rigid-elastic coupling dynamic equation; and determining analysis results of elastic stability and dynamic response from the state-space equation. The present invention can realize efficient and accurate rigid-elastic coupling calculation and analysis.

The invention relates to a shotcrete support parameter adaptability design method considering blasting damage, and belongs to the technical field of tunnel engineering. The problems that the friction coefficient value is empirical, parameter design is not matched with the actual working condition and the design accuracy is low due to neglecting of the shape change of the surface of the surrounding rock caused by blasting damage in the prior art are solved. According to the technical scheme, the method comprises the steps of quantifying a surrounding rock roughness coefficient and calculating a friction coefficient through multi-angle image acquisition and image recognition; the lining thickness is determined by combining the clearance requirement, the deformation allowance and the blasting damage risk; establishing a two-way unequal-pressure elastic mechanical model, and solving lining stress distribution based on a stress function and coulomb friction constraint; and taking support cost minimization as a target, and inversely solving the optimal concrete strength grade and reinforcement ratio by adopting an optimization algorithm. Accurate self-adaptive design of support parameters is realized, stress calculation precision is improved, safety is guaranteed, and cost is reduced.

The invention provides a reinforced concrete structure reinforcement calculation process and method, and the method comprises the following specific steps: carrying out the linear elasticity analysis of a plain concrete structure, calculating the internal force of the plain concrete structure, and calculating the initial reinforcement ratio of the concrete structure meeting the bearing capacity limit state; a preliminary reinforcement scheme is given on the basis of the preliminary reinforcement ratio of the structure; and performing nonlinear finite element analysis on the reinforced concrete structure, calculating a concrete damage state and reinforcement stress, performing crack width checking calculation, and adjusting a preliminary reinforcement scheme. According to the method, the requirements of the bearing capacity limit state and the normal use limit state can be met at the same time, the process is clear, and powerful technical support can be provided for reinforcement design of a reinforced concrete structure.

The invention particularly relates to a tunnel structure deformation monitoring method and system based on optical fiber strain sensing, and relates to the technical field of civil engineering structure health monitoring, and the method comprises the steps: calculating the annular displacement of different sections of a tunnel based on the preprocessed discrete point strain data, the strain and displacement relation based on the elastic mechanics theory, and a cubic spline interpolation algorithm, and then carrying out bicubic spline interpolation curved surface fitting to obtain continuous three-dimensional deformation of the tunnel lining structure. According to the method, a fiber grating array is densely arranged to form a three-dimensional sensing network, in combination with elastic mechanical strain, a displacement relation and cubic spline and bicubic spline interpolation algorithms, discrete strain data is converted into continuous annular displacement of a single section of a tunnel, and then a continuous three-dimensional deformation field of a tunnel lining is further reconstructed; the strain measurement precision is guaranteed, the local deformation characteristics can be carefully captured, and the global deformation rule of the tunnel structure can be comprehensively reflected.

This invention belongs to the field of vibration and sound propagation technology for liquid-filled pipelines, specifically relating to a method, program, device, and storage medium for calculating the modal dispersion characteristics and energy distribution of a liquid-filled elastic tube. Based on three-dimensional linear elasticity theory and wave equations, this invention obtains the governing equations and boundary conditions for the propagation modes of an infinitely long, uniform, isotropic liquid-filled elastic tube. Differential matrices are constructed and solved to obtain the dispersion curves, displacement distributions, and stress distributions of the modes. The power flow of the modes in the fluid and the tube wall is then calculated, ultimately yielding the energy distribution of the modes. This invention only requires the inner diameter, wall thickness, density of the tube wall material, Young's modulus, Poisson's ratio, and density of the liquid inside the elastic tube to obtain the dispersion curves and modal energy distributions of an infinitely long liquid-filled elastic tube. It can accurately, conveniently, and quickly obtain the vibration and sound propagation characteristics of a liquid-filled elastic tube, providing guidance for selecting a suitable pipeline system.

The application discloses a design method of a heterogeneous superstructure material with zero Poisson's ratio and high bearing capacity. In the linear elasticity theory framework, first, two kinds of cell configurations with theoretically positive and negative Poisson's ratio values are selected based on a structural Poisson's ratio calculation formula of a classical beam theory; then, finite element solutions of the Poisson's ratio and the Young's modulus of the selected cells are calculated; and finally, the two kinds of cells with positive and negative Poisson's ratios are assembled in a column and row arrangement mode according to a given layout rule to obtain a heterogeneous lattice superstructure material with zero Poisson's ratio and high bearing capacity. The application can obtain a heterogeneous superstructure material with zero Poisson's ratio and high bearing capacity through cell assembly design. The heterogeneous lattice superstructure material formed by assembly has stronger deformation resistance and one-way deformation capacity of the zero Poisson's ratio structure, and can provide scheme support for actual engineering design.

The invention discloses a construction method of a two-dimensional three-way woven composite material in-plane mechanical isotropy size effect prediction model, and the method discusses the size effect of the tensile property of a TWF system in different loading directions. An elastic mechanics theory and analytic geometry are combined, a new mechanical model is established, and the relation among the sample size, the tensile modulus and the loading angle is quantitatively described. The model clarifies how the local fiber bundle constraint and the reinforcement effect of the woven structure influence the macromechanical behavior, theoretical derivation reveals the size effect of the three-stage mechanical response, and two key aspect ratio thresholds are delimited. The model constructed by the method can overcome the limitation that a typical volume element analysis method neglects a boundary effect, and a theoretical tool is provided for material and size coordination design of spaceflight deployable structures such as space deployable antennas.

The application discloses a shale bedding fracture propagation geometric parameter calculation method, which comprises the following steps: establishing a differential equation group of a shale bedding standard layer according to an elastic mechanics theory, integrating the differential equation group into a partial differential equation group; transforming the partial differential equation group into a common differential equation group, and solving a general solution of the common differential equation group; solving constants in the general solution of the common differential equation group by using a linear spring controlled bedding boundary condition; obtaining a shear slip calculation model of the shale bedding under a space coordinate system; establishing a geometric parameter calculation equation of a shale bedding fracture, and coupling the shear slip calculation model of the shale bedding to obtain a shale bedding fracture propagation geometric parameter calculation model; and performing dynamic simulation on a fracture propagation in a shale gas volume fracturing process, and obtaining a calculation result of a shale bedding fracture propagation geometric parameter. The calculation result of the shale bedding fracture propagation geometric parameter obtained by the application is reliable, and provides a technical reference for shale gas exploration and development and other related work.

The invention provides a linear elasticity accurate calculation method and system for a hoisting structure and a computer readable storage medium, and the method comprises the steps: carrying out the repeated and cyclic solving calculation of a construction structure composite calculation model based on the input through employing a linear elasticity calculation method; and when the difference between the output of the construction structure composite calculation model and the input of the construction structure composite calculation model of the same round is lower than a preset threshold value, taking the output of the construction structure composite calculation model as a target lateral stiffness value, and then obtaining an internal force result or a displacement result corresponding to the target lateral stiffness value. Based on the length of a lifting rope, tension and related material parameters, a deduced normal plane stiffness expression and the elastic constraint equivalent three-dimensional stiffness in the orthogonal direction, the tensile force is iteratively corrected by using structural calculation software until absolute convergence is achieved, so that the accuracy of obtaining the lateral stiffness is improved, an internal force result and a displacement result are accurately obtained, and the stability of the lateral stiffness is improved. And further, an accurate stress analysis result about the hoisting structure is obtained.

The invention discloses an extended finite element-based true three-dimensional numerical simulation method for analyzing fault activity tendency, which comprises the following steps of: representing linear elasticity of a three-dimensional space geologic body by adopting a true three-dimensional model, controlling displacement by passive quantity balance, and adopting a within-plane model; the stress displacement condition of the true three-dimensional fault is represented by constructing a three-dimensional curved surface discontinuous equation; a fluid-solid coupling model is obtained through analysis; representing the change of the permeability in the rock stratum along with the strain; and characterizing the change of fault water flow capacity caused by stress. According to the method, curved surface faults with various dip angles can be analyzed, fault activity is performed according to stick-slip, changes of hydraulic parameters such as permeability in the fault serving as a fracture zone during fault activity are fully considered, the parameters are arranged according to points, the influence of heterogeneity can be considered, and two fluid injection modes (according to flow and water injection pressure) are provided; and the earthquake magnitude can be predicted.

The application discloses a small window analysis method for four-component borehole strain observation data and a related device, relates to the technical field of four-component borehole strain observation data analysis, and comprises the following steps: segmenting four-component borehole strain observation data to be analyzed to obtain four-component borehole strain observation data in multiple unit time periods; performing data analysis on the four-component borehole strain observation data in the unit time period; determining observation errors of observed relative tectonic ground stresses and errors of non-tectonic ground stresses caused by each influencing factor; further determining errors between observed stresses and relative tectonic ground stresses; further determining a value range of a first slope of linear change of the observed relative tectonic ground stress with time; and selecting a slope in the value range of the first slope as a second slope of linear change of the relative tectonic ground stress with time by using a linear elasticity assumption, so that the relative tectonic ground stress in the four-component borehole strain observation data can be extracted.

This invention discloses a method for calculating the energy release rate of delamination damage propagation in composite materials based on shell elements, belonging to the field of composite material delamination damage modeling and efficient energy release rate calculation. The method includes: deriving an equivalent energy release rate calculation method based on energy differential, and proposing a simplified formula for calculating the structural energy release rate under the linear elasticity assumption of the material. Undamaged regions are established using multi-layered plate and shell elements after delamination, and structural damage analysis models are constructed under different damage sizes, structural load conditions, and displacement boundary conditions. The structural response under different damage sizes is calculated and a database is formed. The relationship between damage size and structural strain energy or overall flexibility and stiffness is fitted using a polynomial isofunction fitting method, establishing a reduced-order model for calculating the energy release rate of delamination damage propagation with damage size and external load as inputs. This invention is used to quickly calculate the energy release rate of delamination damage propagation in composite materials, supporting rapid online safety assessment of composite structures.

The invention provides a constitutive model establishment and transient dynamic analysis method considering a plastic domain, and relates to the technical field of constitutive relation and dynamic analysis. The method comprises the following steps: introducing plastic strain parameters corresponding to the yield strength of a material into a J-C constitutive equation at normal temperature, establishing a constitutive model considering a plastic domain, and fitting and solving each parameter in the established constitutive model through test data to obtain a solved constitutive model; the solved constitutive model is subjected to numerical simulation and is compared with test data, so that the reasonability of the solved constitutive model can be verified; the stress deconservative property is verified by establishing an explicit dynamic finite element model and carrying out linear elasticity analysis and elastic-plastic analysis; the method can provide reference for plastic domain constitutive model establishment and transient dynamics deconservative analysis.