Numerical calculation method and device for simulating slippage of duct piece and built-in steel bar

Abstract

The invention relates to a numerical calculation method and device for simulating slippage of a duct piece and a built-in steel bar. The numerical calculation method for simulating slippage of the duct piece and the built-in steel bar comprises the following steps: performing grid division on a three-dimensional shield duct piece according to reinforcement information, endowing the grid three-dimensional shield duct piece with basic physical parameters of concrete, and constructing cable units arranged along actual reinforcement positions, coupling with the concrete model in combination with the calibrated bonding parameters to obtain a concrete model with slippage characteristics; a load path conforming to an engineering scene is applied to the concrete model with the slippage characteristic, nonlinear increment iteration solving is adopted, and simulation time history data is obtained; and finally, performing index calculation and evaluation on the simulation time history data. According to the numerical calculation method for simulating slippage of the duct piece and the built-in steel bar, the problem of overestimation of rigidity and bearing capacity caused by assumption of complete bonding is effectively avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of numerical simulation of lining structures with bond-slip properties, and in particular to a numerical calculation method and device for simulating the slip between segments and embedded steel, electronic equipment and computer storage medium. BACKGROUND

[0002] In engineering structure design and analysis, numerical simulation is an indispensable method. Through numerical calculation, the stress, deformation and damage evolution of the structure can be predicted in the design stage, thereby providing support for structure safety evaluation. Common numerical simulation methods include the finite element method (FEM) and the finite difference method (FDM), both of which belong to the category of numerical simulation of continuous media. They can reproduce the crack development, stiffness degradation and damage propagation process of concrete under external load in a virtual environment, thereby verifying the rationality of the structure design and evaluating its safety margin.

[0003] In the prior art, numerical simulation usually adopts incremental loading and nonlinear solution method. By gradually applying external load and iteratively calculating the response of the structure at each loading step, the stress-strain distribution, stiffness change and ultimate bearing capacity of concrete and steel at each stage can be obtained. In order to handle the interaction between steel and concrete, the common method is to model the steel as a beam element (Beam), and to assume that it is fully bonded with the concrete and does not slip relative to the concrete. If you want to further simulate the slip effect, you need to introduce an interface element (Interface) or a contact element (Contact) between the steel and the concrete to express the relative movement between the two.

[0004] However, the existing simulation method has limitations in some specific structure cases. Taking the segment structure of underground shield tunnel as an example, this type of structure is often accompanied by large bending moment in the stress process, and the mechanical properties can be approximated as the stress behavior of curved beams under bending load. When the steel-concrete interface reaches a certain stress or strain level, relative slip may occur (i.e., displacement of steel relative to concrete), which will weaken the constraint effect of steel on crack closure, change the stress transfer mechanism, and accelerate the crack and damage evolution of concrete, and affect the development trend of damage variables in the Concrete Damage Plasticity (CDP) model.

[0005] In addition, the prior art often ignores the slip effect of the steel-concrete interface, which may overestimate the overall stiffness and bearing capacity of the segment structure of the underground shield tunnel in the simulation results of the prior art. Even in some research or engineering practices, it is realized that the slip needs to be considered, but it is very difficult to accurately incorporate it into the finite element model: on the one hand, special elements or contact algorithms need to be introduced for the interface performance, and accurate bond-slip constitutive parameters need to be provided; on the other hand, the existence of the interface slip increases the nonlinearity and computational complexity of the model, and more experimental data are needed as support.

[0006] Therefore, the prior art has the technical problem of inaccurate evaluation of the stiffness and bearing capacity due to the failure to consider the interface slip when numerically simulating the shield segment structure, which leads to misjudgment of the actual stress performance of the segment and affects the reliability of the safety assessment. SUMMARY

[0007] Therefore, the prior art has the technical problem of inaccurate evaluation of the stiffness and bearing capacity due to the failure to consider the interface slip when numerically simulating the shield segment structure, which leads to misjudgment of the actual stress performance of the segment and affects the reliability of the safety assessment.

[0008] A numerical calculation method for simulating the slip of a segment and embedded steel, comprising the following steps:

[0009] S1: performing mesh division on a three-dimensional shield segment according to reinforcement information to obtain an initialized concrete model;

[0010] S2: constructing a cable element and embedding it into the initialized concrete model with calibrated bond parameters to obtain a concrete model with slip characteristics;

[0011] S3: performing incremental iteration on the concrete model with slip characteristics according to a preset load to obtain simulation time series data;

[0012] S4: performing index calculation and evaluation on the simulation time series data to obtain performance evaluation data of the current shield segment.

[0013] The numerical calculation method for simulating the slip of a segment and embedded steel according to the present application, by replacing the reinforcement path in the concrete with a cable element (Cable), constructing a cable element, and explicitly introducing the bond-slip effect at the steel-concrete interface, effectively avoids the problem of overestimation of stiffness and bearing capacity due to the assumption of complete bonding. At the same time, since the cable element itself can represent axial stress and slip, there is no need to additionally introduce the combination modeling of beam elements and interface elements, thereby reducing the number of interface couplings, reducing the complexity of parameter setting and contact calculation, and improving the convergence and stability of numerical simulation.

[0014] Further, the embedding into the initialized concrete model comprises the following sub-steps:

[0015] convert the steel bar arrangement path in the concrete model into a calculable cable element, to form a concrete model containing the cable element;

[0016] Then, according to the basic physical parameters of the steel bar and the calibrated bond parameters, the cable element in the concrete model containing the cable element is valued, to form a reinforced concrete model with stress response characteristics.

[0017] Accordingly, the present application converts the steel bar arrangement path in the shield segment into a cable element (Cable), and combines the basic physical parameters of the steel bar and the calibrated bond parameters to value, to explicitly reflect the force transmission and slip characteristics of the steel bar-concrete interface, avoid the problem of non-uniform parameters and convergence difficulty in the traditional beam element Beam and interface element Interface combined modeling, and effectively simplify the modeling process and improve the stability and controllability of numerical simulation. In particular, for the shield segment structure, due to the complex reinforcement form and the possibility of large strain under bending, if the slip effect of the steel bar-concrete interface is not considered, the calculation result will deviate from the actual situation; therefore, by introducing the Cable element, the slip effect can be truly reflected under the conditions of complex reinforcement and large strain, which is more suitable for numerical simulation and performance evaluation of the shield segment structure.

[0018] Further, the calibrated bond parameters include cohesive strength, friction angle, shear stiffness, residual cohesive strength, critical slip and residual starting slip, which are obtained by calibration through the following steps:

[0019] Firstly, based on the single-bar pull-out test, the mechanical data set in the pull-out process is collected to form the load-slip curve and stress-strain curve;

[0020] Meanwhile, based on the initialized concrete model, the cable element is introduced, and a set of intermediate bond parameters to be optimized is given to the cable element, and the numerical simulation platform is used to perform incremental iterative calculation on the single-bar pull-out working condition to obtain the corresponding simulated load-slip curve;

[0021] The intermediate bond parameters refer to the intermediate parameter set which has not been completely iterated, and are specifically represented as follows:

[0022]

[0023] In the formula, θ represents the intermediate bond parameter; τ c represents the cohesive strength; represents the friction angle; K s represents the shear stiffness; τ res represents the residual cohesive strength; δ c represents the critical slip; δ res represents the residual starting slip;

[0024] The incremental iteration calculation refers to step by step applying displacement load in a numerical simulation platform, and solving the response of the steel and concrete interface at each loading step to obtain a simulated load-slippage curve;

[0025] Then, a target function is used to calculate the deviation value of the simulated load-slippage curve and the corresponding load-slippage curve in the mechanical data set, to obtain the deviation value of the current intermediate bonding parameter;

[0026] Subsequently, it is judged whether the deviation value of the current intermediate bonding parameter meets the iteration threshold: if not, it is considered that the current intermediate bonding parameter does not converge, an optimization algorithm is called to update and iterate the current intermediate bonding parameter to obtain an updated intermediate bonding parameter, and the incremental iteration calculation is continued; if yes, it is considered that the current intermediate bonding parameter is completed calibration, and it is taken as a calibrated bonding parameter.

[0027] Accordingly, the present application collects the mechanical data of the steel-concrete interface based on the single-steel pulling test, and combines numerical inversion and optimization iteration to obtain a calibrated bonding parameter set which can reflect the stress law of the steel-concrete interface in the initial bonding, slippage development and residual friction three stages, so as to ensure the authenticity and reproducibility of the input parameters of the numerical model, and effectively improve the description ability of the numerical simulation to the whole process of the slippage between the steel and the concrete.

[0028] Further, the specific representation of the target function is as follows:

[0029]

[0030] In the formula, J(θ (t) ) represents the deviation value of the intermediate bonding parameter θ (t) of the tth iteration; E bond represents the target function of the initial bonding stage, and the specific calculation representation is as follows:

[0031]

[0032] In the formula, N1 is used to represent the total number of sampling points in the initial bonding stage; I(·) represents an indication function, which outputs 1 when the condition is met, and otherwise outputs 0; represents the critical slippage corresponding to the intermediate bonding parameter of the tth iteration; P sim (δ i ; θ (t) ) represents the load obtained by the model reaction force when the end displacement is pushed to the slippage δ i corresponding to the i th sampling point under the intermediate bonding parameter of the t th iteration through numerical simulation;

[0033] E slipThe objective function representing the slip development stage is calculated as follows:

[0034]

[0035] In the formula, N2 represents the total number of sampling points in the slip development stage; P represents the residual initiation slip corresponding to the intermediate bonding parameters in the t-th iteration; exp (δ i ) represents the slip amount δ in the mechanics dataset. i At that time, the corresponding load; P ref Indicates the normalized reference value;

[0036] E res The objective function representing the residual friction stage is calculated as follows:

[0037]

[0038] In the formula, N2 represents the total number of sampling points in the slip development stage;

[0039] Indicates the boundary penalty term; This represents the experimental critical slip directly identified from the load-slip curve of a single-rib pull-out test; The residual initiation slip identified by the load-slip curve of the single-rib pull-out test; λ c and λ res These are dimensionless weighting coefficients.

[0040] Accordingly, this invention divides the stress process of the reinforced concrete interface into three stages: initial bonding, slip development, and residual friction, by introducing a phased error term and a boundary penalty term into the objective function. The deviation between the simulated and experimental curves for each stage is calculated. Simultaneously, by adding boundary penalty terms for critical slip and residual initial slip to the objective function, consistency between the numerical simulation output curve and the experimental curve is ensured at the stage transition points. Therefore, this invention not only avoids mismatch phenomena under overall curve fitting but also ensures that the simulation process can truly reflect the mechanical evolution of the entire interface slip process, thereby improving the accuracy of parameter calibration and the reliability of numerical simulation.

[0041] A numerical calculation device for simulating the slippage between tunnel segments and built-in reinforcing bars includes a shield tunnel segment concrete mesh division unit, a cable unit embedding unit, a load simulation unit, and a shield tunnel segment performance evaluation unit.

[0042] The shield tunnel segment concrete mesh division unit is used to divide the three-dimensional shield tunnel segment into meshes according to the reinforcement information to obtain the initial concrete model.

[0043] The cable unit embedding unit is used for constructing the cable unit, embedding the cable unit into the initialized concrete model with the calibrated bond parameters, and obtaining the concrete model with the slip characteristics.

[0044] The load simulation unit is used for performing incremental iteration on the concrete model with the slip characteristics according to the preset load, and obtaining simulation time history data.

[0045] The shield segment performance evaluation unit is used for performing index calculation and evaluation on the simulation time history data, and obtaining performance evaluation data of the current shield segment.

[0046] In order to better understand and implement, the present application is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 A simple structure schematic diagram of the numerical calculation device for simulating segment and built-in steel slip according to the present application;

[0048] Figure 2 A simple flow schematic diagram of the numerical calculation method for simulating segment and built-in steel slip according to the present application;

[0049] Figure 3 A comparison schematic diagram of load-displacement curves of the concrete model with the slip characteristics constructed according to the present application under damage loading conditions and test results;

[0050] Figure 4 A comparison schematic diagram of load-displacement curves of the concrete model with the slip characteristics constructed according to the present application under shield segment ultimate bearing capacity conditions and full-size loading experiments. DETAILED DESCRIPTION

[0051] In order to solve the problem that the existing technology cannot accurately evaluate the stiffness and bearing capacity due to not considering the interface slip when numerically simulating the shield segment structure, the present application first divides a three-dimensional shield segment according to reinforcement information, and gives the meshed three-dimensional shield segment the basic physical parameters of concrete to form a calculable initialized concrete model; then constructs a cable unit arranged along the actual bar position, and embeds the cable unit into the initialized concrete model with calibrated bond parameters to represent the force transmission and relative displacement between the steel bar and the concrete, so as to obtain a concrete model with slip characteristics; on this basis, a load path corresponding to an engineering scene is applied to the concrete model with the slip characteristics, and a nonlinear incremental iteration is used to obtain simulation time history data; finally, index calculation and evaluation are performed on the simulation time history data to obtain performance evaluation data of the current shield segment.

[0052] Accordingly, by explicitly introducing cable elements to simulate the bond slip between the reinforcement and the concrete, the evaluation results are closer to the actual situation by avoiding the overestimation of stiffness and bearing capacity caused by the complete bond assumption; at the same time, the traditional combination of beam elements and explicit interface elements is replaced by cable elements with a parameterized interface, reducing the risk of non-convergence caused by contact tolerance and parameter coupling, and effectively improving the controllability of modeling and calculation.

[0053] Based on the above design, the application provides a numerical calculation method for simulating the slip between the segment and the built-in reinforcement, and based on the method, a numerical calculation device for simulating the slip between the segment and the built-in reinforcement is provided.

[0054] Please refer to Figure 1 and Figure 2 , Figure 1 is a simple structure schematic diagram of the numerical calculation device for simulating the slip between the segment and the built-in reinforcement according to the application, Figure 2 is a simple flowchart schematic diagram of the numerical calculation method for simulating the slip between the segment and the built-in reinforcement according to the application.

[0055] The numerical calculation device for simulating the slip between the segment and the built-in reinforcement comprises a shield segment concrete mesh division unit 1, a cable element embedding unit 2, a load simulation unit 3 and a shield segment performance evaluation unit 4.

[0056] The shield segment concrete mesh division unit 1 is used to perform step S1: performing mesh division on a three-dimensional shield segment according to reinforcement information to obtain an initialized concrete model.

[0057] Specifically, the reinforcement information is a data set describing the internal reinforcement arrangement form and mechanical property parameters of the shield segment, usually including the material type and strength grade of the reinforcement, compression yield, tension yield, density, elastic modulus, geometric characteristics (including diameter, cross-sectional area), arrangement path (such as longitudinal, circumferential, oblique), anchorage length, protection layer thickness and design or construction allowed deviation and other geometric parameters, which are used as the geometric and mechanical input basis for reinforcement construction, mainly determine the distribution path and quantity configuration of the cable element (Cable), which is usually obtained from design drawings, reinforcement detail drawings, construction BIM models or field measurement data.

[0058] The three-dimensional shield segment is a three-dimensional solid geometric model constructed based on the actual lining structure of the project, which is usually established by CAD or finite element pre-processing platform, generally including the inner radius, outer radius, thickness, ring width (longitudinal length), assembly angle (central angle) and opening, joint and other structural geometric parameters of the segment, which are used to define the volume domain and boundary domain of the concrete body, which can usually be directly modeled according to the design drawings, or reconstructed after geometric simplification processing from laser scanning / point cloud data.

[0059] The meshing is used for combining the three-dimensional shield segment with the reinforcement information, and further giving the material constitutive properties of the concrete and the boundary or monitoring set configuration, to generate a numerical mesh model with finite element analysis capability, that is, to form an initialized concrete model, which specifically includes the following sub-steps:

[0060] According to the preset mesh characteristic length, the three-dimensional shield segment is meshed to form an initial finite element mesh model with multiple concrete mesh nodes.

[0061] The steel bar arrangement path in the reinforcement information is imported into the initial finite element mesh model according to a unified coordinate system to form a finite element mesh model with a steel bar arrangement path.

[0062] According to the basic physical parameters of the concrete, the concrete constitutive is selected, the finite element mesh model with the steel bar arrangement path is given a constitutive value, and the boundary or monitoring set is constructed to form an initialized concrete model.

[0063] The basic physical parameters of the concrete are elastic modulus, Poisson's ratio, compressive strength and fracture energy by default; the concrete constitutive is a concrete damaged plasticity (CDP) by default; and the boundary or monitoring set includes a fixed support surface, a loading surface and key response monitoring points by default.

[0064] It should be noted that the concrete material constitutive can be a concrete damaged plasticity (CDP) or other equivalent damage constitutive model or elastic-plastic model according to engineering needs; the boundary or monitoring set can be defined according to different test conditions, loading methods or numerical simulation needs, for example, adding a displacement constraint surface, setting different loading ports or arranging more monitoring points; the steel bar arrangement path can be set according to different reinforcement forms (such as longitudinal arrangement, circumferential arrangement, diagonal arrangement or combination thereof), and different steel bar spacing, layer number, anchoring length and other parameters; the specific geometry modeling or parameter setting is not limited by the present application, and the skilled person can determine it flexibly according to the specific engineering object and analysis target.

[0065] The cable element embedding unit 2 is used to perform step S2: constructing a cable element, and embedding it into the initialized concrete model with calibrated bond parameters to obtain a concrete model with slip characteristics.

[0066] Generally speaking, in the prior art, when coupling the steel bar with the concrete, a combination modeling mode of a beam element and an interface element is usually adopted, which can describe the mechanical relationship between the steel bar and the concrete, but different interface parameter taking modes lack unified standards, and convergence difficulties are easily caused in numerical calculation under cyclic loading or complex boundary conditions, at the same time, the combination modeling mode of the beam element and the interface element is difficult to be effectively coupled with a concrete plastic damage model (CDP), so that the accurate simulation of the damage evolution process is limited. Therefore, the prior art is prone to cause obvious deviation of the evaluation results of the stiffness and the bearing capacity for the structure of the shield segment under the bending action.

[0067] In addition, in other prior art, the steel bar and the concrete are both modeled as solid elements, and an interface element is introduced between the two to simulate the slip, which can reflect the interface effect to some extent in local analysis. However, due to the large number of reinforcement of the shield tunnel segment and the complex arrangement, the introduction of the interface element between the solid-solid elements not only has a huge modeling and calculation amount, but also the slip behavior is often limited by the initial geometric model, such as whether the interface geometry is complete, whether the geometric characteristics of the ribbed steel bar are considered, and the above set forms will affect the accuracy and stability of the calculation results.

[0068] Based on this, the present application constructs a cable element (Cable) as a modeling mode of the steel bar, which can not only explicitly reflect the axial stress and the bond-slip effect in the one-dimensional element, but also the slip process does not depend on the integrity of the solid element geometry, but is directly realized through parameterized control, so that the modeling is more convenient, the calculation is more stable, and it is more suitable for the structure system of the shield segment with complex reinforcement and significant bending.

[0069] Specifically, the embedding into the initialized concrete model includes the following sub-steps:

[0070] The steel bar arrangement path in the initialized concrete model is converted into a calculable cable element (Cable) for bearing axial stress and reflecting the relative slip between the steel bar and the concrete, forming a concrete model containing the cable element.

[0071] Then, according to the basic physical parameters and the calibrated bond parameters of the steel bar, the cable element in the concrete model containing the cable element is valued, forming a reinforced concrete model with stress response characteristics.

[0072] Among them, the basic physical parameters of the steel bar include the steel bar diameter, the anchoring length and the contact area by default;

[0073] The calibrated bonding parameters are slip parameters obtained by calibration, and specifically include cohesion strength, friction angle, shear stiffness, residual cohesion strength, critical slip and residual starting slip; and the calibration is inversion of a data set collected through a single-steel bar pull-out test, used to reflect the slip law of the steel bar and the concrete interface.

[0074] It should be noted that the present application no longer relies on the traditional mesh node coupling mode, but draws on the modeling concept of soil slope cable element, and converts the steel bar path arranged in the concrete into a cable element. At the same time, as a one-dimensional linear element, the cable element can bear axial force, and the bonding-slip relationship between the steel bar and the concrete is explicitly reproduced through parameter input mode, thereby avoiding the additional introduction of interface elements, and similar to the principle of soil slope anchor rod used to simulate the relative slip between the anchor rod-rock interface in the slope treatment, the present application migrates this concept to the modeling of the shield segment, and gives the cable element cohesion strength, friction angle and shear stiffness and other characteristics by calibrating the bonding parameters, so that it can truly reflect the whole slip process of the steel bar-concrete interface and its influence on the overall mechanical properties.

[0075] In addition, it should be additionally explained that, since the slip behavior of the steel bar and the concrete interface is a complex nonlinear problem, it cannot be completely determined by theoretical formula alone, therefore, calibration is carried out in combination with test data, that is, the interface mechanical response curve is obtained through a single-steel bar pull-out test, and numerical inversion and parameter optimization iteration are combined, so as to obtain a set of calibrated bonding parameters that can truly reflect the slip law, and the specific steps of calibration are as follows:

[0076] Firstly, based on the single-steel bar pull-out test, the mechanical data set in the pull-out process is collected to form the load-slip curve and the stress-strain curve, which are specifically represented as follows:

[0077] D={(δ i ,P i ,ε i ,σ i )|i=1,2,…,N}

[0078] In the formula, D represents the mechanical data set; δ i represents the steel bar end slip at the i-th sampling point in the single-steel bar pull-out test, and N represents the total number of sampling points; P i represents the pull-out load corresponding to the i-th sampling point in the single-steel bar pull-out test; ε i represents the local strain corresponding to the i-th sampling point in the single-steel bar pull-out test; and σ i represents the local stress corresponding to the i-th sampling point in the single-steel bar pull-out test.

[0079] Among them, the load-slip curve P(δ) in the mechanical data set is {(δ i ,P i} and stress-strain curve σ(ε) = {(ε i ,σ i )|i=1,2,…,N} are used to depict the stress behavior of the steel-concrete interface at different stages, including the initial bonding stage, the slip development stage and the residual friction stage, as the prior value range of the characteristic parameters such as the cohesive strength, the friction angle and the shear stiffness, and as the initial input of the subsequent calibration process.

[0080] It should be noted that the single-reinforcement pull-out test can be carried out by the center pull-out test method, and the test conditions can refer to the relevant provisions of the Concrete Structure Test Method Standard (GB / T 50152-2012), which usually needs to carry out multiple tests (such as 36 groups) to ensure the statistical stability of the parameters; at the same time, the concrete specimen is generally made into a cube, and the common size is 160mmx160mmx160mm and 250mmx250mmx250mm; in addition, in order to ensure that the interface effect can fully develop, the length of the specimen is defaulted to be 10 times the diameter of the steel bar, and the bonding length of the steel bar in the concrete is defaulted to be 5 times the diameter of the steel bar, through the above setting, to ensure the stability of the mechanical data set and the effectiveness of the data, to provide a reliable basis for the subsequent numerical simulation calibration.

[0081] Meanwhile, on the basis of initializing the concrete model, a cable element is introduced, and a set of intermediate bonding parameters to be optimized is assigned to it, and the numerical simulation platform is used to carry out incremental iterative calculation on the single-reinforcement pull-out working condition to obtain the corresponding simulated load-slip curve.

[0082] The intermediate bonding parameters are intermediate parameter sets that have not been completely iterated, and the initial values thereof are obtained by setting in the characteristic range of the load-slip curve and the stress-strain curve of the mechanical data set, and then the intermediate bonding parameters are iteratively updated to gradually approach the real bonding parameters, and the intermediate bonding parameters can be specifically represented according to the following expression:

[0083]

[0084] In the formula, θ represents the intermediate bonding parameter; τ c represents the cohesive strength, and corresponds to the peak point of the load-slip curve; represents the friction angle, which is the parameter between the residual stage friction strength and the normal stress, and is used to represent the friction slip law; K s represents the shear stiffness, which is the tangent stiffness of the initial bonding stage curve; τ res represents the residual cohesive strength, which is the average interface shear stress corresponding to the platform of the residual friction stage; δ c represents the critical slip, which is the slip amount when the curve rises linearly into the peak point, and is used to represent the critical point of the initial bonding stage; δres representing the residual initial slip, which is the slip amount when the load-slip curve drops from the peak value and is about to enter the residual platform, that is, the initial slip amount indicating the entry into the residual friction stage;

[0085] The incremental iteration calculation refers to step-by-step application of displacement load in a numerical simulation platform, and solving the response of the steel bar and the concrete interface at each loading step, so as to obtain the simulated load-slip curve.

[0086] Then, the objective function is used to calculate the deviation value of the simulated load-slip curve and the corresponding load-slip curve in the mechanical data set, to obtain the deviation value of the current intermediate bonding parameter, which can be specifically referred to the following calculation expression:

[0087]

[0088] In the formula, J (θ (t) ) is the objective function, which is used to represent the deviation value of the intermediate bonding parameter corresponding to the tthiteration; P sim (δ i ; θ (t) ) represents the load obtained by the model reaction force when the end displacement is pushed to the slip amount δ i corresponding to the ithsampling point under the intermediate bonding parameter of the tthiteration; P exp (δ i ) represents the corresponding load when the slip amount is δ i in the mechanical data set; P ref represents the normalized reference value, which can adopt max j (P exp (δ j )), that is, the peak value of the load-slip curve in the mechanical data set, or can adopt the relative error P exp (δ i ), or take 1 without considering the normalization to adopt the absolute value error, and the application does not specifically limit the selection of the normalized reference value.

[0089] In another embodiment, considering that the slip behavior between the steel bar and the concrete has an initial bonding stage, a slip development stage and a residual friction stage, therefore, the application adopts a three-section adaptive objective function to calculate the deviation value of the current intermediate bonding parameter, which can be specifically referred to the following calculation expression:

[0090]

[0091] In the formula, E bond represents the objective function of the initial bonding stage, which is used to measure the deviation value between the simulated load-slip curve and the corresponding load-slip curve in the mechanical data set in the initial bonding stage, and the specific calculation can be referred to the following expression:

[0092]

[0093] In the formula, N1 represents the total number of sampling points in the initial bonding stage; I(·) represents the indicator function, which outputs 1 when the condition is met and 0 otherwise. This represents the critical slip corresponding to the intermediate bonding parameters in the t-th iteration;

[0094] E slip The objective function representing the slip development stage measures the deviation between the simulated load-slip curve and the corresponding load-slip curve in the mechanical dataset. Its specific calculation can be found in the following expression:

[0095]

[0096] In the formula, N2 represents the total number of sampling points in the slip development stage; This represents the residual initiation slip corresponding to the intermediate bonding parameters in the t-th iteration;

[0097] E res The objective function for the residual friction stage measures the deviation between the simulated load-slip curve and the corresponding load-slip curve in the mechanical dataset. Its specific calculation can be found in the following expression:

[0098]

[0099] In the formula, N2 represents the total number of sampling points in the slip development stage;

[0100] The boundary penalty term is used to constrain the relative consistency between the numerical simulation curve and the experimental curve at different stages, that is, the relative consistency between the critical slip and the residual starting slip. In the actual iterative optimization process, if only the overall curve difference is minimized, it may cause the curve output by the numerical simulation to be misfitted with the curve of the mechanical dataset, that is, mismatch phenomenon. This causes the overall curve to seem to match, but there is a deviation at the stage inflection point. Therefore, the boundary penalty term is used to constrain the alignment between the critical slip and the residual starting slip, thereby alleviating the mismatch phenomenon.

[0101] This represents the experimental critical slip directly identified from the load-slip curve of a single-rib pull-out test; The residual initiation slip identified by the load-slip curve of the single-rib pull-out test; λ c and λ res These are dimensionless weighting coefficients used to adjust the proportion of the penalty term in the overall objective function, with a default value range of [0.01, 0.1].

[0102] Subsequently, it is judged whether the deviation value of the current intermediate bonding parameter meets the iteration threshold: if not, it is considered that the current intermediate bonding parameter does not converge, and the optimization algorithm needs to be called to update and iterate the current intermediate bonding parameter to obtain an updated intermediate bonding parameter, and the incremental iteration calculation is continued; if yes, it is considered that the current intermediate bonding parameter completes the calibration and is taken as the calibrated bonding parameter.

[0103] The iteration threshold can be specifically referred to the following judgment expression:

[0104]

[0105] In the formula, represents the relative error of the deviation value of the intermediate bonding parameter in two consecutive iterations, which is used to judge whether the optimization process tends to be stable; ∈ represents the convergence threshold of the relative error, and the default value range is [10 -4 ,10 -2 ]; J min represents the minimum threshold value of the deviation value of the intermediate bonding parameter, and when the deviation value of the intermediate bonding parameter decreases to the minimum threshold value, it is considered that the convergence has been achieved; t max represents the maximum number of iterations allowed, which is used to prevent the optimization process from falling into infinite iteration, and is determined by the calculation resources and the convergence speed;

[0106] The optimization algorithm adopts particle swarm optimization (PSO), which is used for global optimization of the intermediate bonding parameter, so that the target function gradually decreases to meet the iteration threshold. The global optimization of the intermediate bonding parameter in the t+1 iteration can be referred to the following expression:

[0107]

[0108] In the formula, represents the actual physical value of the dth component in the ith candidate solution in the t+1 iteration, that is, any one parameter in , and the candidate solution thereof represents a candidate component combination of the intermediate bonding parameter in the search space;

[0109] represents the normalized parameter value of the dth component in the ith candidate solution in the t iteration. By using the normalized parameter value, the difference between different dimensionless quantities is avoided, and the parameter components are updated in a unified scale. The specific calculation can be referred to the following expression:

[0110]

[0111] In the formula, denotes the d-th component of the intermediate bond parameter in the t-th iteration; and denotes the lower and upper limit of the physical quantity corresponding to the d-th component of the intermediate bond parameter, which is determined by the curve characteristics or empirical boundaries obtained from the single-steel bar pull-out test, to ensure that the parameter value is in a reasonable physical feasible interval;

[0112] is an inertia term, used to ensure the continuity of the search and avoid premature convergence to a local optimum, and ω (t) denotes the inertia weight in the t-th iteration, used to balance global search and local convergence, and gradually decreases with iteration; denotes the velocity of the i-th candidate solution in the d-th component at the t-th iteration, i.e. the update step of the normalized parameter value of the component, used to control the adjustment amplitude of the normalized parameter value of the component in the next iteration;

[0113] is an individual learning term, used to guide the current candidate solution to the normalized parameter value of the component with the best historical performance in the search space; c1 denotes an individual learning factor, used to adjust the degree of the normalized parameter value of the current component to the historical optimal solution; denotes a uniform random number in the interval [0, 1] at the t-th iteration, to increase the randomness of the search; denotes the individual optimal normalized parameter value of the d-th component in all iteration histories of the i-th candidate solution;

[0114] is a group learning term, used to promote the normalized parameter value of the component with the best performance in the group in the search space; c2 denotes a group learning factor, used to adjust the degree of the normalized parameter value of the current component to the global optimal solution; denotes a uniform random number in the interval [0, 1] at the t-th iteration; denotes the global optimal normalized parameter value of the d-th component in all candidate solutions.

[0115] It should be noted that when it is judged that the current intermediate bond parameter fails to meet the iteration threshold, it means that there is still room for improvement in the existing search range, and therefore the optimization algorithm needs to be called to search for a new potential solution in the parameter space as the intermediate bond parameter for the next iteration. At this time, the particle swarm optimization (PSO) algorithm adopted by the present application introduces a group search mechanism for candidate solutions in the parameter space, so that each iteration not only depends on the local information of the current solution itself, but also can consider the optimal performance of each candidate solution in the historical iteration process.

[0116] In the search process of the optimization algorithm, each candidate solution represents a set of intermediate bonding parameters, and the updating direction of the candidate solution is affected by two factors: one is the historical optimal value of the candidate solution (individual optimal), which reflects the optimal performance (i.e., the lowest deviation value) that the candidate solution has ever reached in the previous iteration, thereby ensuring that the algorithm can retain the local optimal experience; the other is the global optimal value of all candidate solutions in the iteration history (population optimal), which reflects the optimal performance explored by the population in the search space, thereby ensuring that the algorithm can gradually approach the optimal solution in the global range. Therefore, through the joint action of the inertia term, the individual learning term and the population learning term, the candidate solution can dynamically adjust the updating direction and the updating amplitude in the search space to achieve the balance between exploration and convergence.

[0117] Accordingly, when the threshold condition is not met, the parameter components of the candidate solution are updated by calling the optimization algorithm, so that the intermediate bonding parameters used in the next iteration are closer to the global optimal solution, and numerical simulation and target function calculation are performed again under the parameters. This cycle is repeated until the threshold condition is met or the maximum number of iterations is reached, thereby ensuring that the selection of the calibrated bonding parameters can reflect both local characteristics and global rationality, and ensuring the convergence and effectiveness of the optimization results.

[0118] The load simulation unit 3 is used to perform step S3: according to the preset load, the concrete model with slip characteristics is subjected to incremental iteration to obtain simulation time history data.

[0119] Specifically, the load is achieved by arranging loading blocks in the mid-span region of the parameter-perfect concrete model and applying vertical displacement control boundaries at a constant rate to realize displacement load, so as to trigger the parameter-perfect concrete model to enter the whole process from the elastic stage to the cracking, damage and ultimate bearing capacity.

[0120] The incremental iteration represents that the numerical simulation platform applies displacement load in small steps in the loading process, and updates the mechanical state inside the parameter-perfect concrete model in each step; the mechanical state includes updating the tensile and compressive damage variables and stiffness degradation in the concrete plastic damage model (CDP), and updating the slip response of the cable element, which is jointly controlled by the cohesive strength, friction angle and shear stiffness, so that the concrete model can truly reflect the influence of interface bonding degradation and relative slip on internal force redistribution when entering the post-cracking stage, and then output complete simulation time history data.

[0121] The simulation time history data are used to record the response results of the shield segment in the whole process of numerical simulation, which specifically include the load-displacement curve, the interface slip curve, the steel reinforcement axial force distribution, the concrete damage factor field, and the displacement time history response of each key point in the loading process.

[0122] The load-displacement curve is used to reflect the stiffness change and ultimate bearing capacity of the whole structure of the concrete model, and depict the whole process from the elastic stage to cracking, damage and failure.

[0123] The interface slip curve is used to describe the relative displacement evolution law of the cable element and the concrete interface in the concrete model in the loading process, so as to reflect the whole process of interface bonding degradation and friction slip.

[0124] The steel bar axial force distribution is used to reveal the force transmission of the cable element along the path in the concrete model, and to judge the force concentration and yield development of the cable element in different regions of the concrete model.

[0125] The concrete damage factor field is used to reflect the cracking area and damage mode of the concrete in the concrete model, so as to simulate the expansion process of damage in the concrete model.

[0126] The displacement time history response is used to record the evolution of the displacement of the key monitoring points of the whole structure of the concrete model with time or loading step in the whole loading process, so as to evaluate the deformation mode and ultimate state of the structure.

[0127] It should be emphasized that the present application does not limit the type of numerical solution platform and iterative algorithm, and can be realized under the finite element method (FEM) or the finite difference method (FDM). In the implementation process, the solving platform can adopt Newton-Raphson method, arc length method, adaptive step strategy or other nonlinear iterative strategies according to different working conditions and calculation requirements, so as to ensure the convergence and stability of the calculation; and by assigning the calibrated bonding parameters to the cable element in the concrete model, the steel-concrete interface slip is characterized and fed back in the whole process of numerical simulation.

[0128] Accordingly, under any load path and boundary condition consistent with the engineering scene, the consistency simulation of bearing capacity degradation, post-cracking internal force redistribution and toughness response can be maintained, and reliable results for performance evaluation of the shield segment can be output. It should be noted that the present application does not make unified provisions for specific boundary conditions and loading methods, and the actual working conditions can be set in engineering, as long as the parameter values are correct, the corresponding working conditions can be accurately reproduced.

[0129] The shield segment performance evaluation unit 4 is used to execute step S4: index calculation and evaluation on the simulation time history data to obtain the performance evaluation data of the current shield segment.

[0130] Specifically, the index calculation and evaluation, according to the interface slip curve in the simulation time history data, the interface behavior is divided into initial bonding stage, slip development stage and residual friction stage, and each stage is aligned with other response results in the simulation time history data, and the performance index set in different slip stages is obtained, that is, the performance evaluation data of the current shield segment is obtained, which specifically includes:

[0131] According to the fact that the tangent stiffness of the local curve in the interface slip curve is consistent with the shear stiffness in the calibrated bonding parameter, and the slip amount does not exceed the critical slip value, it is determined that the interface is in the initial bonding stage, and the corresponding load displacement curve in the simulation time history data is aligned with the steel bar axial force distribution for evaluation, which is used to determine the initial stiffness and stress uniformity of the shield segment in the elastic working state, so as to obtain the evaluation result of the initial bonding stage, which includes the initial stiffness coefficient, the steel bar stress uniformity and the interface bonding integrity rate by default.

[0132] Wherein, the critical slip value is determined by the turning point before the peak value of the corresponding load slip curve in the calibrated bonding parameter.

[0133] When the cohesion strength in the interface slip curve reaches the peak value corresponding to the cohesion strength in the calibrated bonding parameter, and the slip amount is in a preset interval, it is determined that the interface is in the slip development stage, and the interface slip curve in the simulation time history data is aligned with the concrete damage factor field for evaluation, which is used to depict the coupling relationship between slip expansion and crack evolution, and the evaluation result of the slip development stage is obtained, which includes the maximum slip amount, the slip section proportion, the crack expansion rate and the energy dissipation value by default.

[0134] Wherein, the preset interval is the interval from the critical slip value to the slip amount corresponding to the residual value when the cohesion strength of the corresponding load slip curve in the calibrated bonding parameter decreases to the residual value.

[0135] When the shear strength in the interface slip curve decreases to the corresponding residual strength in the calibrated bonding parameter, and the slip amount exceeds a preset value, it is determined that the interface is in the residual friction stage, and the post-peak section of the load displacement curve in the simulation time history data is aligned with the key point displacement time history response for evaluation, which is used to identify the structural ultimate bearing capacity and failure mode of the shield segment, and the evaluation result of the residual friction stage is obtained, which includes the ultimate bearing capacity, the residual bearing capacity, the bearing degradation rate, the failure section proportion and the key point displacement overrun rate by default.

[0136] Wherein, the preset value is the slip amount corresponding to the residual value when the cohesion strength of the corresponding load slip curve in the calibrated bonding parameter decreases to the residual value.

[0137] Finally, the evaluation results of the initial bonding stage, the slip development stage and the residual friction stage are integrated to obtain the performance evaluation data of the shield segment.

[0138] It is important to emphasize that this invention aligns the entire process of interface sliding with other mechanical response data from the simulation time history data to achieve the evaluation from local interface behavior to overall performance. Furthermore, by using parameters from the calibrated bonding parameters as evaluation thresholds, the consistency between simulation and experiment is ensured, thereby improving the reliability and accuracy of performance evaluation.

[0139] Furthermore, since the stress state, yield characteristics, and energy dissipation mechanisms of reinforcing bars differ under various engineering conditions, they need to be determined based on the actual situation. Therefore, reinforcing bars can adopt elastic constitutive models, elastoplastic constitutive models, or other equivalent yield models to simulate their stress and yielding processes. However, regardless of the specific reinforcing bar constitutive model used, the core of this invention lies in characterizing the bond-slip effect between the reinforcing bar and concrete through cable elements, thereby realistically reflecting the impact of the entire slip process on the overall mechanical properties. Therefore, this invention only requires that the cable elements can correctly achieve the full process control and feedback of interface slip, without restricting the form of the reinforcing bar constitutive model.

[0140] Compared to existing technologies, this invention uses cable elements instead of the traditional combination of beam and interface elements for modeling, explicitly introducing the bond-slip effect at the steel-concrete interface, thus avoiding the overestimation of stiffness and bearing capacity caused by the assumption of complete bond.

[0141] Please see Figure 3 , Figure 3 This is a schematic diagram comparing the load-displacement curves obtained from the concrete model with slip characteristics constructed in this invention under damage loading conditions with experimental results. Figure 3 As can be seen, the numerical simulation results are highly consistent with the experimental results. In the elastic stage, the curve slope is large, indicating high overall stiffness. As loading continues, the curve slope gradually decreases, damage begins to appear on the inner surface of the segments, and the structure enters the plastic stage. The numerical simulation can accurately reproduce the nonlinear evolution law shown in the experiment, with a load deviation of only 0.76% from the experimental value, verifying the authenticity and effectiveness of the model after introducing the bond-slip effect through the cable element.

[0142] Please see Figure 4 , Figure 4 This is a schematic diagram comparing the load-displacement curves obtained from the concrete model with sliding characteristics constructed in this invention under the ultimate bearing capacity condition of a tunnel segment with those from a full-scale loading experiment. Figure 4It can be seen that, in the initial loading stage, the numerical calculation curve of the application is highly consistent with the test curve; when the mid-span vertical displacement is in the range of 10-20mm, the simulation result is slightly higher than the test value, which is due to the effect of the gradual development of a large number of micro-cracks in the actual test piece, while the numerical simulation only triggers crack formation after damage accumulation to a certain extent, thus producing a slight difference in this range, but as the loading continues, the curves again maintain good consistency. Therefore, by adopting the cable element and calibrated bond parameters, the application can not only truly reflect the slip effect of the steel-concrete interface, but also accurately reproduce the whole process of the shield segment from the elastic stage, the damage stage to the ultimate failure stage on the overall response level, ensuring the reliability of the simulation result.

[0143] Based on the same inventive concept, the application further provides an electronic device, which can be a server, a desktop computing device or a mobile computing device (for example, a laptop computing device, a handheld computing device, a tablet computer, a netbook, etc.) or a terminal device. The device comprises one or more processors and a memory, wherein the processor is configured to execute a program to implement the numerical calculation method for simulating segment and embedded steel slip according to the embodiments of the application; and the memory is configured to store the computer program executable by the processor.

[0144] Based on the same inventive concept, the application further provides a computer readable storage medium, which corresponds to the numerical calculation method for simulating segment and embedded steel slip according to any one of the preceding embodiments, and the computer readable storage medium has a computer program stored thereon, which, when executed by a processor, implements the steps of the numerical calculation method for simulating segment and embedded steel slip according to any one of the preceding embodiments.

[0145] The application can adopt the form of a computer program product implemented on one or more storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing program code. The computer usable storage medium includes permanent and non-permanent, removable and non-removable media, which can be realized by any method or technology. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to: phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape disk storage or other magnetic storage device, or any other non-transmission medium that can be used to store information accessible by a computing device.

[0146] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and the present application also intends to include these modifications and improvements.

Claims

1. A numerical calculation method for simulating segment and internal steel slip, characterized in that, The method comprises the following steps: S1: according to the reinforcement information, the three-dimensional shield segment is meshed to obtain an initialized concrete model; S2: a cable element is constructed and embedded into the initialized concrete model with calibrated bond parameters to obtain a concrete model with slip characteristics; S3: according to a preset load, the concrete model with slip characteristics is subjected to incremental iteration to obtain simulation time series data; S4: index calculation and evaluation are performed on the simulation time series data to obtain performance evaluation data of the current shield segment.

2. The numerical calculation method for simulating segment and internal steel bar slip according to claim 1, characterized in that, The embedding into the initialized concrete model comprises the following sub-steps: The steel bar arrangement path in the initialized concrete model is converted into a calculable cable element to form a concrete model containing the cable element; Then, according to the basic physical parameters of the steel bar and the calibrated bond parameters, the cable element in the concrete model containing the cable element is valued to form a reinforced concrete model with stress response characteristics.

3. The numerical calculation method for simulating segment and internal steel bar slip according to claim 2, characterized in that, The calibrated bond parameters comprise cohesion strength, friction angle, shear stiffness, residual cohesion strength, critical slip and residual starting slip, which are obtained by calibration through the following steps: Firstly, based on the single-steel bar pull-out test, a mechanical data set in the pull-out process is collected to form a load-slip curve and a stress-strain curve; At the same time, on the basis of the initialized concrete model, a cable element is introduced and a set of intermediate bond parameters to be optimized is given to the cable element, and the single-steel bar pull-out working condition is calculated by incremental iteration using a numerical simulation platform to obtain a corresponding simulated load-slip curve; The intermediate bond parameters refer to an intermediate parameter set that has not been completely iterated, and are specifically represented as follows: where θ represents the intermediate bonding parameter; τ c represents the cohesion strength; represents the friction angle; K s represents the shear stiffness; τ res represents the residual cohesion strength; δ c represents the critical slip; δ res represents the residual onset slip; The incremental iteration calculation refers to gradually applying a displacement load in the numerical simulation platform, and solving the response of the steel bar and the concrete interface at each loading step to obtain a simulated load-slip curve; Then, a target function is used to calculate the deviation value of the simulated load-slip curve and the corresponding load-slip curve in the mechanical data set to obtain the deviation value of the current intermediate bond parameters; Subsequently, it is judged whether the deviation value of the current intermediate bond parameters meets the iteration threshold: if not, it is considered that the current intermediate bond parameters have not converged, an optimization algorithm is called to update and iterate the current intermediate bond parameters to obtain updated intermediate bond parameters, and the incremental iteration calculation is continued; if yes, it is considered that the calibration of the current intermediate bond parameters is completed, and the intermediate bond parameters are taken as the calibrated bond parameters.

4. The numerical calculation method for simulating segment and internal steel bar slip according to claim 3, characterized in that, The target function is specifically represented as follows: where J(θ (t) ) denotes the intermediate bonding parameter θ (t) at the tth iteration; E bond denotes the error value corresponding to the initial bonding phase, which is calculated as follows: where N1 is used to represent the total number of sampling points in the initial bonding stage; I(·) represents an indicator function, which outputs 1 when the condition is met, and otherwise outputs 0; represents the critical slip corresponding to the intermediate bonding parameter of the t th iteration; P sim represents the load obtained by the model reaction force when the end displacement is pushed to the slip δ i ; θ (t) i corresponding to the i th sampling point under the intermediate bonding parameter of the t th iteration through numerical simulation; i ; θ (t) i corresponding to the i th sampling point under the intermediate bonding parameter of the t th iteration through numerical simulation; E slip The objective function representing the development phase of the slip is calculated as follows: In the formula, N2 is used to represent the total number of sampling points in the slip development stage; represents the residual initial slip corresponding to the intermediate bonding parameter of the tth iteration; P exp represents the initial slip corresponding to the bonding parameter of the tth iteration; P i represents the load corresponding to the slip δ i in the mechanical data set; P ref represents the normalized reference value; E res The objective function representing the residual friction phase is calculated as follows: In the formula, N2 is used to represent the total number of sampling points in the slip development stage; denotes the boundary penalty term; denotes the experimental critical slip directly identified from the load-slip curve of the single-lap pull-out test; denotes the experimental residual starting slip identified from the load-slip curve of the single-lap pull-out test; λ c and λ res are dimensionless weight coefficients, respectively.

5. A numerical calculation device for simulating segment and internal steel slip, characterized in that, The method comprises a shield segment concrete meshing unit, a cable element embedding unit, a load simulation unit and a shield segment performance evaluation unit. The shield segment concrete meshing unit is used to mesh a three-dimensional shield segment according to reinforcement information to obtain an initialized concrete model; The cable element embedding unit is used to construct a cable element and embed it into the initialized concrete model with calibrated bond parameters to obtain a concrete model with slip characteristics; The load simulation unit is used to perform incremental iteration on the concrete model with slip characteristics according to a preset load to obtain simulation time series data; The shield segment performance evaluation unit is configured to perform index calculation and evaluation on the simulation time-history data to obtain performance evaluation data of the current shield segment.

6. The numerical calculation device for simulating segment and internal steel bar slip according to claim 5, characterized in that, The embedding into the initialized concrete model comprises the following sub-steps: The arrangement path of the steel bars in the initialized concrete model is converted into a calculable cable element to form a concrete model containing the cable element; Then, the cable element in the concrete model containing the cable element is assigned based on the basic physical parameters of the steel bars and the calibrated bond parameters to form a reinforced concrete model with stress response characteristics.

7. The numerical calculation device for simulating segment and internal steel bar slip according to claim 6, characterized in that, The calibrated bond parameters include cohesion strength, friction angle, shear stiffness, residual cohesion strength, critical slip and residual starting slip, which are obtained by calibration through the following steps: First, based on the single-bar pull-out test, a mechanical data set during the pulling process is collected to form a load-slip curve and a stress-strain curve; Meanwhile, based on the initialized concrete model, the cable element is introduced and a set of intermediate bond parameters to be optimized is assigned to the cable element, and an incremental iterative calculation is performed on the single-bar pull-out working condition by using a numerical simulation platform to obtain a corresponding simulated load-slip curve; The intermediate bond parameters refer to an intermediate parameter set that has not been completely iterated, and are specifically represented as follows: where θ represents the intermediate bonding parameter; τ c represents the cohesion strength; represents the friction angle; K s represents the shear stiffness; τ res represents the residual cohesion strength; δ c represents the critical slip; δ res represents the residual onset slip; The incremental iterative calculation refers to gradually applying a displacement load in the numerical simulation platform, and solving the response of the steel bar and the concrete interface at each loading step to obtain a simulated load-slip curve; Then, a target function is used to calculate the deviation value of the simulated load-slip curve and the corresponding load-slip curve in the mechanical data set to obtain the deviation value of the current intermediate bond parameters; Subsequently, it is judged whether the deviation value of the current intermediate bond parameters meets the iteration threshold: if not, it is considered that the current intermediate bond parameters have not converged, an optimization algorithm is called to update and iterate the current intermediate bond parameters to obtain updated intermediate bond parameters, and the incremental iterative calculation is continued; if yes, it is considered that the current intermediate bond parameters are calibrated and are taken as the calibrated bond parameters.

8. The numerical calculation device for simulating segment and internal steel bar slip according to claim 7, characterized in that, The target function is specifically represented as follows: where J(θ (t) ) denotes the intermediate bonding parameter θ (t) at the tth iteration; E bond denotes the objective function for the initial bonding stage, which is calculated as follows: where N1 is used to represent the total number of sampling points in the initial bonding stage; I(·) represents an indicator function, which outputs 1 when the condition is met, and otherwise outputs 0; denotes the critical slip corresponding to the intermediate bonding parameter of the t-th iteration; P sim (δ i ; θ (t) ) denotes the load obtained by the model reaction force when the end displacement is pushed to the slip δ i corresponding to the i-th sampling point under the intermediate bonding parameter of the t-th iteration through numerical simulation. E slip The objective function representing the development phase of the slip is calculated as follows: N2 is used to represent the total number of sampling points in the slip development stage; P represents the residual starting slip corresponding to the intermediate bonding parameter of the tth iteration; exp (δ i ) represents the load corresponding to the slip δ i in the mechanical data set; and ref P represents the normalized reference value. E res The objective function representing the residual friction phase is calculated as follows: In the formula, N2 is used to represent the total number of sampling points in the slip development stage. denotes the boundary penalty term; denotes the experimental critical slip identified directly from the load-slip curve of the single-lap pull-out test; denotes the experimental residual starting slip identified from the load-slip curve of the single-lap pull-out test; λ c and λ res are dimensionless weight coefficients, respectively.

9. An electronic device comprising: A memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the numerical calculation method for simulating the slip of the segment and the embedded steel bars according to any one of claims 1-4 when executing the computer program.

10. A computer-readable storage medium storing computer-executable instructions, the computer-executable instructions comprising: The computer executable instructions are executed by the processor to implement the numerical calculation method for simulating the slip of the segment and the embedded steel bars according to any one of claims 1-4.

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