A method and system for analyzing the reinforcement performance of a continuous ECC material on a bridge deck

Abstract

The present application relates to the technical field of bridge deck ECC material reinforcement, in particular to a bridge deck continuous ECC material reinforcement performance analysis method and system, comprising the following steps: obtaining bridge structure parameters, ECC reinforcement parameters, interface connection parameters, interface treatment parameters, load working condition parameters and bridge deck continuous area field response data; establishing a parameterized simulation model comprising a bridge deck slab calculation unit, a beam end calculation unit, an ECC reinforcement layer calculation unit and an interface connection calculation unit; using the field response data to sequentially calibrate the ECC constitutive parameters and the interface connection parameters, and applying temperature working conditions and beam end rotation working conditions to obtain initial state data before vehicle fatigue action; importing the initial state data into a vehicle fatigue simulation model and performing vehicle fatigue simulation in stages, updating the ECC material performance parameters and the interface connection performance parameters, and forming a risk field.

Description

Technical Field

[0001] This invention relates to the field of bridge deck ECC material reinforcement technology, and in particular to a method and system for analyzing the reinforcement performance of continuous bridge deck ECC materials. Background Technology

[0002] ECC materials have attracted attention in bridge structure repair and reinforcement due to their high tensile deformation capacity and crack control capabilities. For continuous ECC reinforcement structures on bridge decks, the reinforcement effect depends not only on the properties of the ECC material itself, but also on factors such as the existing bridge deck structural condition, interface connection performance, interface treatment methods, beam end deformation, and vehicle load spectrum. Evaluation based solely on material design parameters or simplified calculation models cannot fully reflect the stress, deformation, and interface degradation characteristics of the continuous bridge deck under actual service conditions.

[0003] In some existing bridge reinforcement performance analysis methods, parameter acquisition is mostly focused on structural dimensions, material strength, or load parameters, with insufficient utilization of the correlation between ECC reinforcement parameters, interface connection parameters, interface treatment parameters, and field response data. Some analysis models focus on the overall response of the bridge deck or reinforcement layer, and do not adequately characterize the synergistic effect between the existing bridge deck structure, the ECC reinforcement layer, and the interface connection state between the two, making it difficult to fully reflect the bonding, slippage, and debonding evolution behavior between the ECC reinforcement layer and the existing bridge deck.

[0004] Furthermore, the constitutive parameters of ECC materials and interface bonding parameters may have coupled effects. Without a proper parameter calibration sequence, the reliability of the model's fit to the field response can be easily affected. Some fatigue analyses begin from an ideal initial state, failing to fully consider the initial effects of temperature conditions, beam end rotation conditions, and existing service conditions, which may reduce the accuracy of fatigue performance evaluation results.

[0005] Furthermore, some existing reinforcement performance evaluation methods still use maximum stress, maximum strain, single-point crack width, or local damage indicators as evaluation criteria. It is difficult to correlate different degradation forms such as ECC reinforcement layer cracking, ECC fatigue damage, interface slip, and interface debonding with the spatial location of the calculation unit to express the risk. It is also difficult to provide targeted basis for optimizing ECC reinforcement thickness, ECC reinforcement length, and interface treatment parameters.

[0006] Therefore, for bridge deck continuous ECC material reinforcement scenarios, it is still necessary to solve the problem of how to comprehensively utilize bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface processing parameters, load condition parameters and field response data, reduce the error caused by the coupling calibration of material parameters and interface parameters, consider the impact of the existing state on vehicle fatigue response, and form risk assessment results related to spatial location, so as to provide a basis for optimizing the bridge deck continuous ECC reinforcement scheme. Summary of the Invention

[0007] The purpose of this invention is to address the problem in the prior art of how to comprehensively utilize bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface processing parameters, load condition parameters, and field response data to reduce the errors caused by the coupling calibration of material parameters and interface parameters, consider the impact of the existing state on vehicle fatigue response, and form a risk assessment result associated with spatial location, thereby providing a basis for optimizing the continuous ECC reinforcement scheme for bridge decks. Therefore, this invention proposes a method and system for analyzing the reinforcement performance of continuous ECC materials for bridge decks.

[0008] To achieve the above objectives, the present invention provides a method for analyzing the reinforcement performance of continuous ECC material on bridge decks, comprising the following steps: S1, obtaining bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface processing parameters, load condition parameters, and field response data of the continuous bridge deck area;

[0009] S2. Based on the obtained bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface processing parameters and load condition parameters, establish a parametric simulation model of the continuous ECC reinforcement structure of the bridge deck. The parametric simulation model includes bridge deck calculation units, beam end calculation units, ECC reinforcement layer calculation units and interface connection calculation units.

[0010] S3. First, calibrate the ECC constitutive parameters using the field response data of the continuous area of ​​the bridge deck, and then calibrate the interface connection parameters under the condition of fixed ECC constitutive parameters to obtain the calibrated parametric simulation model. Apply temperature conditions and beam end rotation conditions to the calibrated parametric simulation model to obtain the initial state data before vehicle fatigue. The initial state data includes the initial stress field, initial strain field, initial interface slip field and initial damage field.

[0011] S4. Import the initial state data into the vehicle fatigue simulation model as the initial condition for the vehicle fatigue simulation. The vehicle fatigue simulation model is either a calculation sub-model of the parametric simulation model under vehicle fatigue conditions, or a fatigue analysis model formed by state mapping from the parametric simulation model. Perform the vehicle fatigue simulation according to the preset fatigue segmentation rules, and update the ECC material performance parameters and interface bonding performance parameters after each fatigue stage. Based on the updated simulation results, calculate the risk value and risk assessment results of each calculation unit according to the preset risk assessment rules, and form a risk field according to the spatial location of the calculation units. The risk assessment results include at least one of the following: ECC reinforcement layer cracking risk, ECC fatigue damage risk, interface slippage risk, and interface debonding risk.

[0012] S5. Based on the location of the calculation unit in the risk field where the risk value reaches or exceeds the preset risk threshold and its risk assessment results, determine the dominant risk type and risk distribution location, and select at least one from ECC reinforcement thickness, ECC reinforcement length and interface processing parameters for adjustment according to the dominant risk type and risk distribution location, and generate an adjusted reinforcement optimization scheme.

[0013] Compared with existing technologies, this invention comprehensively acquires bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface treatment parameters, load condition parameters, and field response data of the continuous bridge deck area. This allows for the analysis of the reinforcement performance of continuous ECC materials on the bridge deck to be based on more complete fundamental data, reducing analytical biases caused by relying solely on single structural, material, or load parameters. Based on this, a parametric simulation model is established, including bridge deck calculation units, beam end calculation units, ECC reinforcement layer calculation units, and interface connection calculation units. This allows the existing bridge deck, adjacent beam ends, ECC reinforcement layer, and the interface connection state between them to be characterized within the same analytical system. This is beneficial for reflecting the stress coordination, interface slippage, and debonding evolution behavior between the ECC reinforcement layer and the existing bridge deck. Simultaneously, by first calibrating the ECC constitutive parameters using field response data, and then calibrating the interface connection parameters under the condition of fixed ECC constitutive parameters, the influence of the coupling between material and interface parameters on the model calibration results can be reduced, improving the simulation model's accuracy in reflecting field responses. To improve the reliability of the simulation, the initial stress field, initial strain field, initial interface slip field, and initial damage field formed by temperature conditions, beam end rotation conditions, and existing service conditions are introduced before the vehicle fatigue simulation. This allows the vehicle fatigue simulation to consider the initial stress and damage state of the continuous bridge deck area. Furthermore, the ECC material performance parameters and interface connection performance parameters are updated during the phased vehicle fatigue simulation process, dynamically reflecting the gradual degradation of the ECC reinforcement layer and interface connection performance under fatigue. Finally, the risk value and risk assessment results of each calculation unit are calculated based on the updated simulation results, and a risk field is formed according to the spatial location of the calculation unit. This allows the ECC reinforcement layer cracking risk, ECC fatigue damage risk, interface slip risk, and interface debonding risk to be associated with specific locations, facilitating the determination of the dominant risk type and risk distribution location. Based on this, at least one of the ECC reinforcement thickness, ECC reinforcement length, and interface treatment parameters can be adjusted, providing a more targeted optimization basis for continuous ECC reinforcement schemes for bridge decks and improving the rationality of reinforcement parameter selection. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the method steps of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0016] Example 1 illustrates the parameter acquisition and field response data processing process in the method for analyzing the performance of continuous ECC material reinforcement on bridge decks. It focuses on explaining the definition, source, acquisition method, storage method, and correspondence between the bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface processing parameters, load condition parameters, and field response data of the continuous bridge deck area and subsequent simulation analysis.

[0017] Specifically, the following steps are taken: First, obtain the bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface treatment parameters, load condition parameters, and field response data of the continuous zone of the bridge deck. Bridge structural parameters include bridge deck thickness, bridge deck width, spacing between adjacent beam ends, beam end support conditions, length of the continuous zone of the bridge deck, existing concrete strength grade, and reinforcement layout parameters. ECC reinforcement parameters include ECC reinforcement layer thickness, ECC reinforcement length, ECC elastic modulus, ECC tensile strength, ECC ultimate tensile strain, and ECC fatigue performance parameters. Load condition parameters include vehicle axle load, wheelbase, vehicle load spectrum, fatigue cycle count, temperature variation amplitude, and beam end rotation parameters.

[0018] In this embodiment, all parameters are recorded and calculated using a unified unit system. Interface connection parameters characterize the connection performance between the ECC reinforcement layer and the existing bridge deck, specifically including interface normal stiffness, interface tangential stiffness, interface tensile strength, interface shear strength, interface fracture energy, and interface slip control limit. The interface slip control limit refers to the maximum allowable relative slip between the ECC reinforcement layer and the existing bridge deck, provided that the interface connection performance meets the design requirements. The interface bond stiffness is characterized by both interface normal stiffness and interface tangential stiffness. Interface normal stiffness characterizes the resistance to normal cracking or debonding, while interface tangential stiffness characterizes the interface shear transmission and relative slip resistance.

[0019] Interface slip control limits can be determined by interface shear tests, interface pull-out tests, bridge structural design documents, or bridge deck continuity zone inspection and evaluation documents. When determined by interface shear tests, the relative slip value corresponding to the point where the design shear capacity is reached, a significant decrease in stiffness occurs, or the slip amount reaches the test control state in the interface shear load-slip curve can be determined as the interface slip control limit. When determined by interface pull-out tests, the relative displacement of the interface corresponding to the point where identifiable separation of the interface occurs, the bearing capacity decreases, or the design control state is reached during the pull-out process can be determined as the interface slip control limit. When determined by bridge structural design documents or inspection and evaluation documents, the allowable interface slip amount, interface deformation control value, or limit related to interface connection performance specified therein can be used as the interface slip control limit.

[0020] Interface treatment parameters characterize the surface treatment state and connection reinforcement measures of the existing bridge deck before the construction of the ECC reinforcement layer. These parameters include interface roughness, roughening depth, adhesive type, adhesive coating thickness, adhesive tensile strength, adhesive shear strength, rebar diameter, rebar spacing, and shear connector spacing. These interface treatment parameters can be determined through construction plans, on-site inspection records, material testing reports, or interface connection tests. For example, interface roughness and roughening depth can be obtained through surface profile measurement, sand spreading method, 3D scanning, or on-site roughening records; adhesive type, coating thickness, tensile strength, and shear strength can be obtained through material manufacturer data, construction records, or test reports; and rebar diameter, rebar spacing, and shear connector spacing can be obtained through design drawings, construction records, or on-site verification data.

[0021] The field response data for the continuous bridge deck area are collected from the continuous structural areas at the ends of adjacent beams. Field measuring points are located at at least one of the following locations: near adjacent beam ends, in the middle of the continuous bridge deck area, at the end of the ECC reinforcement layer, in the vehicle wheel track area, and in areas with weak interface connections. Structural deformation measuring points can be located at the mid-span of the continuous bridge deck area, at the ends of adjacent beams, and near supports; strain measuring points can be located on the surface of the ECC reinforcement layer, the surface of the existing bridge deck, and in the tension area of ​​the continuous bridge deck area; interface response measuring points can be located at the end of the ECC reinforcement layer, near beam ends, and in areas where interface slippage or debonding is anticipated. The location of each measuring point is recorded using measuring point numbers and corresponding coordinates, which can be expressed using the longitudinal, transverse, and vertical coordinates of the bridge.

[0022] To facilitate subsequent model calibration and fatigue analysis, the field response data of the continuous bridge deck area are stored in association according to the measuring point number, acquisition time, and load case number. The measuring point number is used to identify the spatial location of each measuring point in the continuous bridge deck area, the acquisition time is used to identify the time when the response data was collected, and the load case number is used to identify the corresponding vehicle load case, temperature case, beam end rotation case, or combined case. For static load or low-speed vehicle loading cases, field response data can be collected according to each loading level or each vehicle position; for dynamic cases such as vehicle traffic or fatigue, the sampling frequency is determined according to the vehicle speed, structural response frequency, and sensor performance, so that the sampled data can identify the peak value of the structural response and the interface slip change process.

[0023] The field response data for the continuous zone of the bridge deck includes structural deformation data, strain data, crack data, and interface response data. Specifically, the structural deformation data includes bridge deck deflection, vertical displacement, beam end rotation, and relative displacement between adjacent beam ends; the strain data includes strain of the existing bridge deck, strain of the ECC reinforcement layer, and tensile and compressive strain at key locations in the continuous zone of the bridge deck; the crack data includes crack width and crack location; and the interface response data includes the amount of interface slippage and debonding length between the ECC reinforcement layer and the existing bridge deck.

[0024] Field response data can be obtained through one or more of the following methods: displacement gauges, rotation sensors, strain gauges, crack width monitoring devices, interface slip gauges, acoustic testing, infrared testing, radar testing, ultrasonic testing, or manual testing and recording. Interface slip can be obtained using displacement sensors, digital image correlation methods, or displacement target measurements placed between the ECC reinforcement layer and the existing bridge deck. Interface debonding length can be determined through impact testing, ultrasonic testing, infrared thermal imaging, ground-penetrating radar testing, or grooving verification, and recorded according to the continuous length of the debonding area along the longitudinal or transverse direction of the bridge. For crack locations and interface debonding locations, their relative positional relationships with beam ends, wheel tracks, reinforcement layer ends, or computational unit boundaries should be recorded for subsequent correlation with the simulation model.

[0025] After acquiring the parameters and field response data, the interface connection parameters are used as input parameters for the interface connection calculation unit in the subsequent parametric simulation model. These parameters characterize the normal connection, tangential connection, tensile failure, shear failure, fracture degradation, and slip control state between the ECC reinforcement layer and the existing bridge deck. The interface processing parameters serve as the basis for selecting interface connection parameter values, verifying interface connection performance, and optimizing subsequent reinforcement. The field response data are used as reference data for model calibration and risk assessment, and are used for subsequent ECC constitutive parameter calibration, interface connection parameter calibration, and risk field generation.

[0026] In the subsequent calibration of ECC constitutive parameters, strain data, crack width, and deflection from the field response data can be selected as calibration bases to match the ECC reinforcement layer strain, crack width in the continuous bridge deck area, and bridge deck deflection output by the simulation model with the field-acquired values. In the subsequent calibration of interface connection parameters, interface slip and interface debonding length from the field response data can be selected as calibration bases to match the interface slip and debonding states output by the simulation model with the field-acquired values. For cases where field measurement points and simulation calculation units do not completely overlap, the field response data can be mapped to the corresponding bridge deck calculation unit, ECC reinforcement layer calculation unit, or interface connection calculation unit based on the measurement point coordinates, unit number, node coordinates, or spatial interpolation relationship. Alternatively, the response results of adjacent nodes or adjacent units in the simulation model can be interpolated to the field measurement point locations and compared with the field-acquired values.

[0027] This embodiment clearly defines the interface connection parameters, interface processing parameters, and field response data of the continuous bridge deck area, as well as their sources, acquisition methods, storage methods, and correspondence with subsequent simulation models. This enables the interface connection parameters, interface processing parameters, and field response data to be continuously incorporated into the parameter acquisition, model calibration, fatigue analysis, and reinforcement optimization processes.

[0028] Example 2 illustrates the parametric simulation model establishment, step-by-step calibration of ECC constitutive parameters and interface connection parameters, initial state data generation and mapping, and staged vehicle fatigue simulation and performance parameter update process in the bridge deck continuous ECC material reinforcement performance analysis method.

[0029] After acquiring bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface treatment parameters, load condition parameters, and field response data of the continuous bridge deck area, a parametric simulation model of the continuous ECC-reinforced bridge deck structure was established. The parametric simulation model includes bridge deck calculation units, beam end calculation units, ECC reinforcement layer calculation units, and interface connection calculation units. The bridge deck calculation units characterize the stress and deformation of the existing bridge deck under vehicle loads, temperature effects, and beam end deformation. The beam end calculation units characterize the vertical displacement, rotation angle, and relative displacement of adjacent beam ends under temperature conditions, beam end rotation conditions, and vehicle load conditions. The ECC reinforcement layer calculation units characterize the tensile deformation, crack development state, stiffness degradation, and fatigue damage state of the ECC reinforcement layer. The interface connection calculation units are located between the bridge deck calculation units and the ECC reinforcement layer calculation units to characterize the adhesion, shear transfer, relative slippage, and debonding states between the ECC reinforcement layer and the existing bridge deck.

[0030] During modeling, bridge structural parameters are used to determine the geometry, support boundaries, and material properties of the bridge deck and beam end calculation units; ECC reinforcement parameters are used to determine the thickness, length, elastic modulus, tensile strength, ultimate tensile strain, and fatigue performance of the ECC reinforcement layer calculation units; interface connection parameters are used to determine the normal stiffness, tangential stiffness, tensile strength, shear strength, fracture energy, and slip control state of the interface connection calculation units; and interface processing parameters serve as the basis for determining interface connection performance values ​​and subsequent optimization adjustments. Force and displacement transfer between different calculation units is achieved through node coupling, contact relationships, bond-slip relationships, or interface unit connection relationships. As a specific modeling method, the bridge deck and beam end calculation units use beam elements, shell elements, or solid elements; the ECC reinforcement layer calculation units use shell elements or solid elements; and the interface connection calculation units use zero-thickness interface elements, bond-slip elements, or contact elements. The boundary conditions, material parameters, and initial state variables of each unit are input in the same unit system.

[0031] Among them, the bridge deck thickness, bridge deck width, distance between adjacent beam ends, length of continuous zone of bridge deck, ECC reinforcement layer thickness, ECC reinforcement length, roughening depth, rebar diameter, rebar spacing, and shear connector spacing are length-related parameters; ECC elastic modulus, ECC tensile strength, interface tensile strength, interface shear strength, and interface shear stress are stress or strength-related parameters; interface normal stiffness, interface tangential stiffness, and interface fracture energy are input according to the selected finite element unit system and kept consistent in the same calculation model.

[0032] After completing the initial parametric simulation model, the model parameters were calibrated step-by-step using field response data from the continuous bridge deck area. First, the ECC constitutive parameters were calibrated. Strain data, crack width, and deflection from the field response data were selected as reference data. The normalized errors between simulated strain and field strain data, between simulated crack width and field crack width, and between simulated deflection and field deflection were weighted to construct the ECC constitutive error function. The ECC constitutive parameters include at least one of the following: ECC elastic modulus, ECC tensile strength, ECC ultimate tensile strain, tensile hardening segment parameters, and post-cracking stiffness degradation parameters.

[0033] The normalization error is determined as follows: the absolute value of the difference between the simulated value and the reference value is taken as the absolute value of the response data difference; the maximum value among the absolute value of the reference value, the corresponding allowable limit, and the preset minimum normalization value is taken as the normalization benchmark value; and the ratio of the absolute value of the response data difference to the normalization benchmark value is taken as the normalization error. The corresponding allowable limit can be derived from the control values ​​set for this type of response data in bridge structural design specifications, testing and evaluation specifications, or test plans; the preset minimum normalization value can be determined based on the resolution of the measuring equipment, the minimum effective value of the field response data, or the minimum effective value of the test data. By setting a preset minimum normalization value, distortion of the normalization error can be avoided when the reference value is close to zero.

[0034] The ECC constitutive error function is obtained by weighting the strain normalization error, crack width normalization error, and deflection normalization error according to preset weights. These preset weights can be determined based on the sensitivity of different response data to the ECC constitutive parameters, measurement reliability, and the focus of engineering evaluation. When the main evaluation objects for the continuous bridge deck area are ECC tensile deformation and crack control, the weights of strain normalization error and crack width normalization error can be higher than those of deflection normalization error; when the main evaluation object is overall bridge deck deformation control, the weight of deflection normalization error can be increased accordingly. All weights are non-negative and normalized to a sum of 1.

[0035] When adjusting the ECC constitutive parameters, a least-squares iterative algorithm, particle swarm optimization algorithm, or genetic algorithm can be used to gradually reduce the ECC constitutive error function. Adjustment of the ECC constitutive parameters stops when the ECC constitutive error function is less than or equal to the first convergence criterion value; adjustment also stops when the ECC constitutive error function is greater than the first convergence criterion value and the number of iterations reaches a first preset number, and the parameters at which adjustment stops are taken as the calibrated ECC constitutive parameters. The first convergence criterion value can be determined based on field test errors, sensor accuracy, model calculation errors, and engineering allowable deviations; the first preset number of iterations can be determined based on the number of parameters, algorithm convergence speed, and computational resources. If the decrease in the ECC constitutive error function is less than a preset change threshold after multiple consecutive iterations, the ECC constitutive parameter calibration can also be considered to have reached a stable state.

[0036] After the ECC constitutive parameters are calibrated, the interface connection parameters are calibrated again while keeping the calibrated ECC constitutive parameters unchanged. Interface slip, debonding length, and interface shear stress reference data from the field response data are selected as reference data. The normalized errors between simulated and field interface slip, between simulated and field debonding lengths, and between simulated and reference shear stress values ​​are weighted to construct an interface error function. Interface connection parameters include at least one of the following: interface normal stiffness, interface tangential stiffness, interface tensile strength, interface shear strength, and interface fracture energy.

[0037] The reference shear stress value is determined by the interface shear strength test value. Specifically, the shear stress level corresponding to the field load condition in the interface shear strength test can be used as the reference shear stress value; alternatively, the reference shear stress value can be obtained by multiplying the interface shear strength test value by a preset utilization factor; or the shear stress value corresponding to the interface shear strength test reaching the design control state, exhibiting significant slippage or stiffness reduction can be used as the reference shear stress value. The preset utilization factor can be determined based on the design safety reserve, testing and evaluation level, or test plan. In this way, a correspondence can be established between the reference shear stress value and the interface shear strength test results, avoiding direct comparison between the simulated interface shear stress and the unconditional ultimate strength value.

[0038] The interface error function is obtained by weighting the interface slip normalization error, interface debonding length normalization error, and interface shear stress normalization error according to preset weights. The preset weights can be determined based on the sensitivity of interface slip, interface debonding, and interface shear stress to the interface connection state. When significant interface slip exists in the continuous area of ​​the bridge deck, the weight of the interface slip normalization error can be increased; when a debonding area is detected, the weight of the interface debonding length normalization error can be increased; when the interface shear strength controls the connection safety, the weight of the interface shear stress normalization error can be increased. Each weight is a non-negative number and is normalized so that the sum of all weights is 1.

[0039] When adjusting the interface connection parameters, least squares iterative algorithms, particle swarm optimization algorithms, or genetic algorithms can be used to gradually reduce the interface error function. When the interface error function is less than or equal to the interface parameter calibration convergence threshold, adjustment of the interface connection parameters is stopped; when the interface error function is greater than the interface parameter calibration convergence threshold and the number of iterations reaches the second preset number, adjustment of the interface connection parameters is also stopped, and the parameters at which adjustment stops are used as the calibrated interface connection parameters. The interface parameter calibration convergence threshold can be determined based on the interface slip detection error, debonding length detection error, interface shear test discreteness, and engineering allowable deviation; the second preset number of iterations can be determined based on the number of interface connection parameters and the algorithm's convergence speed. By first calibrating the ECC constitutive parameters and then fixing the ECC constitutive parameters to calibrate the interface connection parameters, the calibration instability caused by the mutual compensation of ECC material deformation error and interface slip error can be reduced, allowing the material response and interface response to be constrained separately in the model.

[0040] After parameter calibration, temperature and beam end rotation conditions are applied to the calibrated parametric simulation model. The temperature condition simulates the expansion and contraction deformation, additional stress, and relative interface slippage in the continuous region of the bridge deck under temperature rise and fall. The beam end rotation condition simulates the rotation angle differences between adjacent beam ends caused by support deformation, vehicle load, or temperature effects. Through this calculation process, initial state data before vehicle fatigue is obtained. The initial state data includes the initial stress field, initial strain field, initial interface slip field, and initial damage field.

[0041] The initial damage field represents the existing damage state of the continuous area of ​​the bridge deck before vehicle fatigue. The initial damage field can be determined from field crack data, interface debonding length, interface slip, existing inspection and evaluation results, or damage variables output by the calibration model. For ECC-reinforced layer calculation units, the initial damage value can be determined based on crack width, crack location, ECC tensile strain level, or ECC damage variables; for interface connection calculation units, the initial damage value can be determined based on interface slip, interface debonding length, interface shear stress level, or interface damage variables. The initial damage field can be represented by damage level, damage variables, or element state identifiers, and associated with the corresponding calculation unit or node location.

[0042] Initial state data is mapped to bridge deck calculation units, beam end calculation units, ECC reinforcement layer calculation units, and interface connection calculation units in the vehicle fatigue simulation model according to element number, node coordinates, or spatial interpolation relationships. When the parametric simulation model and the vehicle fatigue simulation model use the same mesh, values ​​can be directly assigned according to element number or node number; when the two meshes are not completely consistent, mapping can be performed according to node coordinates, element center coordinates, or interpolation relationships between adjacent elements. After mapping, the initial state of the vehicle fatigue simulation model is no longer an ideal stress-free and damage-free state, but rather an initial stress, deformation, slip, and damage state that includes the effects of temperature, beam end rotation, and existing service conditions. When using spatial interpolation relationships for mapping, one of the following methods can be used: nearest neighbor mapping, linear interpolation, finite element shape function interpolation, or inverse distance weighted interpolation; the mapping variables must include at least stress, strain, interface slip, damage variables, and element state identifiers.

[0043] The vehicle fatigue simulation model is either a calculation sub-model of the parametric simulation model under vehicle fatigue conditions, or an independent fatigue analysis model formed by mapping the parametric simulation model through node coordinates, element numbers, and state variables; the bridge deck calculation unit, beam end calculation unit, ECC reinforcement layer calculation unit, and interface connection calculation unit used by both have the same physical meaning and coordinate reference.

[0044] In the vehicle fatigue simulation phase, the vehicle fatigue condition is divided into multiple fatigue stages according to the vehicle load spectrum. Each fatigue stage has a corresponding number of fatigue cycles and axle load combination. The vehicle load spectrum can be determined based on traffic survey data, bridge inspection reports, design load standards, or measured vehicle traffic data; fatigue stages can be divided according to vehicle axle load level, cumulative number of cycles, traffic volume distribution, or degree of damage growth. The vehicle fatigue simulation starts from the first fatigue stage and applies the corresponding axle load combination and number of fatigue cycles stage by stage.

[0045] After the k-th fatigue stage, the ECC tensile strain amplitude, ECC allowable fatigue strain amplitude, and fatigue cycle number of the ECC reinforced layer calculation unit during that fatigue stage are extracted to calculate the fatigue damage variables of the ECC material. The ECC allowable fatigue strain amplitude can be determined from ECC material fatigue test data, material design parameters, or engineering experience parameters. The ECC material fatigue damage variables can be determined based on the ratio of the ECC tensile strain amplitude to the ECC allowable fatigue strain amplitude, the number of fatigue cycles, and the fatigue degradation relationship of the ECC material. Alternatively, the cumulative damage can be calculated using the ratio of the number of fatigue cycles to the allowable number of fatigue cycles.

[0046] The fatigue damage variable of ECC materials can be determined by a stage-based accumulation method: when the ECC tensile strain amplitude is lower than the ECC fatigue allowable strain amplitude, the ratio of the number of fatigue cycles corresponding to that fatigue stage to the first allowable fatigue cycle count is taken as the ECC fatigue damage increment for that stage; when the ECC tensile strain amplitude reaches or exceeds the ECC fatigue allowable strain amplitude, the ratio of the number of fatigue cycles corresponding to that fatigue stage to the second allowable fatigue cycle count is taken as the ECC fatigue damage increment for that stage; wherein, the second allowable fatigue cycle count is less than the first allowable fatigue cycle count. The ECC fatigue damage increments from multiple fatigue stages are accumulated to form the ECC material fatigue damage variable. The first and second allowable fatigue cycle counts can be determined by ECC material fatigue testing, material design parameters, or engineering experience parameters. Specifically, it can be calculated according to... Calculation, where For the fatigue damage variable of the ECC material after stage k, This represents the number of fatigue cycles in the k-th stage. The number of allowable fatigue cycles corresponds to the ratio of the ECC tensile strain amplitude to the ECC fatigue allowable strain amplitude.

[0047] In one embodiment, the fatigue damage level table for ECC materials may include four levels: low damage, medium damage, high damage, and severe damage. Each level corresponds to the range of values ​​for the fatigue damage variable of ECC materials, the stiffness reduction factor of ECC materials, and the tensile strength reduction factor of ECC materials, respectively. Moreover, as the fatigue damage variable of ECC materials increases, the stiffness reduction factor of ECC materials and the tensile strength reduction factor of ECC materials do not increase.

[0048] The fatigue damage level of ECC materials is determined based on fatigue damage variables. A first, second, and third ECC damage threshold can be set, with the first threshold lower than the second, and the second lower than the third. When the fatigue damage variable is less than the first threshold, it is classified as a low damage level, corresponding to a first ECC material stiffness reduction factor. When the fatigue damage variable is greater than or equal to the first threshold and less than the second threshold, it is classified as a medium damage level, corresponding to a second threshold. When the fatigue damage variable is greater than or equal to the second threshold and less than the third threshold, it is classified as a high damage level, corresponding to a third threshold. When the fatigue damage variable is greater than or equal to the third threshold, it is classified as a severe damage level, corresponding to a fourth threshold. The stiffness reduction factors for the first, second, third, and fourth ECC materials decrease sequentially. The ECC damage threshold and ECC material stiffness reduction factors can be determined from ECC material fatigue test data, material design parameters, or engineering experience parameters. All the aforementioned ECC material fatigue damage variables, damage thresholds, and reduction factors are dimensionless parameters; damage variables can be limited to the range of 0 to 1. When the calculated value exceeds 1, it is counted as 1 in the severe damage level.

[0049] The ECC material stiffness is updated based on the ECC material stiffness reduction factor corresponding to the ECC material fatigue damage level. The updated ECC material stiffness can be obtained by multiplying the initial ECC material stiffness by the corresponding ECC material stiffness reduction factor; alternatively, it can be obtained by multiplying the ECC material stiffness at the end of the previous fatigue stage by the corresponding ECC material stiffness reduction factor. The ECC tensile strength can be updated synchronously according to the strength reduction factor corresponding to the ECC material fatigue damage level, or it can be updated based on the strength degradation relationship obtained from ECC fatigue tests. Correspondingly, the updated ECC material stiffness can be expressed as... The updated ECC tensile strength can be expressed as: ,in : The updated ECC material stiffness after the kth fatigue stage; ECC material stiffness after the k-1th fatigue stage ends; : The ECC material stiffness reduction factor corresponding to the kth fatigue stage; : The updated ECC tensile strength after the kth fatigue stage; ECC tensile strength after the k-1th fatigue stage; : The ECC tensile strength reduction factor corresponding to the kth fatigue stage.

[0050] Simultaneously, after the kth fatigue stage, the interface shear stress amplitude, interface shear strength, interface slip amplitude, interface slip control limit, and number of fatigue cycles within that fatigue stage are extracted from the interface connection calculation unit to calculate the interface fatigue damage variables. The interface fatigue damage variables can be determined based on the ratio of interface shear stress amplitude to interface shear strength, the ratio of interface slip amplitude to interface slip control limit, the number of fatigue cycles, and the interface fatigue degradation relationship. Alternatively, the cumulative damage can be calculated using the ratio of the number of fatigue cycles to the allowable number of fatigue cycles for the interface. The interface fatigue damage variables, interface damage threshold, and interface bond stiffness reduction factor can all be expressed as dimensionless parameters.

[0051] Interface fatigue damage variables can be determined using a stage-accumulation method: when the interface shear stress amplitude is lower than a preset proportion of the interface shear strength, and the interface slip amplitude is lower than a preset proportion of the interface slip control limit, the ratio of the fatigue cycle count corresponding to that fatigue stage to the allowable fatigue cycle count of the first interface is taken as the interface fatigue damage increment for that stage; when the interface shear stress amplitude reaches or exceeds a preset proportion of the interface shear strength, or the interface slip amplitude reaches or exceeds a preset proportion of the interface slip control limit, the ratio of the fatigue cycle count corresponding to that fatigue stage to the allowable fatigue cycle count of the second interface is taken as the interface fatigue damage increment for that stage; wherein, the allowable fatigue cycle count of the second interface is less than the allowable fatigue cycle count of the first interface. The interface fatigue damage increments from multiple fatigue stages are accumulated to form the interface fatigue damage variable. The allowable fatigue cycle count of the first interface and the allowable fatigue cycle count of the second interface can be determined by interface fatigue tests, interface shear tests, interface pull-out tests, or engineering experience parameters. Specifically, it can be determined according to... Calculate, where, : Interface fatigue damage variable after the end of the kth fatigue stage; : Interface fatigue damage variable after the end of the k-1th fatigue stage; The number of fatigue cycles corresponding to the kth fatigue stage; The allowable number of fatigue cycles is determined by the ratio of the interface shear stress amplitude to the interface shear strength and the ratio of the interface slip amplitude to the interface slip control limit during the k-th fatigue stage.

[0052] In one embodiment, the interface fatigue damage level table may include four levels: low damage, medium damage, high damage, and severe damage. Each level corresponds to the range of interface fatigue damage variables, the interface bond stiffness reduction factor, and the interface shear strength reduction factor, respectively. Moreover, as the interface fatigue damage variables increase, the interface bond stiffness reduction factor and the interface shear strength reduction factor do not increase.

[0053] The interface fatigue damage level is determined based on interface fatigue damage variables. A first interface damage threshold, a second interface damage threshold, and a third interface damage threshold can be set, with the first interface damage threshold being less than the second interface damage threshold, and the second interface damage threshold being less than the third interface damage threshold. When the interface fatigue damage variable is less than the first interface damage threshold, it is determined to be a low damage level, corresponding to the first interface bond stiffness reduction factor; when the interface fatigue damage variable is greater than or equal to the first interface damage threshold and less than the second interface damage threshold, it is determined to be a medium damage level, corresponding to the second interface bond stiffness reduction factor; when the interface fatigue damage variable is greater than or equal to the second interface damage threshold and less than the third interface damage threshold, it is determined to be a high damage level, corresponding to the third interface bond stiffness reduction factor; when the interface fatigue damage variable is greater than or equal to the third interface damage threshold, it is determined to be a severe damage level, corresponding to the fourth interface bond stiffness reduction factor. The first, second, third, and fourth interface bond stiffness reduction factors decrease sequentially. The interface damage threshold and the interface bond stiffness reduction factor can be determined by interface fatigue test, interface shear test, interface pull-out test or engineering empirical parameters.

[0054] The interface bond stiffness is updated based on the interface bond stiffness reduction factor corresponding to the interface fatigue damage level. The updated interface bond stiffness can be obtained by multiplying the initial interface bond stiffness by the corresponding interface bond stiffness reduction factor; alternatively, it can be obtained by multiplying the interface bond stiffness at the end of the previous fatigue stage by the corresponding interface bond stiffness reduction factor. The interface shear strength can be updated synchronously according to the strength reduction factor corresponding to the interface fatigue damage level, or it can be updated based on the strength degradation relationship obtained from interface fatigue tests or interface shear tests. Correspondingly, the updated interface bond stiffness can be expressed as... The updated interface shear strength can be expressed as ,in : The interface bonding stiffness updated after the kth fatigue stage; : Interface bond stiffness after the k-1th fatigue stage ends; : The interface bond stiffness reduction factor corresponding to the kth fatigue stage; : The interface shear strength updated after the kth fatigue stage; : Interfacial shear strength after the k-1th fatigue stage ends; : The reduction factor of the interfacial shear strength corresponding to the kth fatigue stage.

[0055] After updating the ECC material performance parameters and interface bonding performance parameters for the kth fatigue stage, the updated ECC material stiffness, ECC tensile strength, interface bond stiffness, and interface shear strength are used for vehicle fatigue simulation in the (k+1)th fatigue stage. By iteratively executing fatigue stage calculations and performance parameter updates, the gradual degradation of the ECC reinforcement layer and interface bonding performance under vehicle fatigue can be simulated. If the fatigue damage level of the ECC material or the interface fatigue damage level reaches the severe damage level after a certain fatigue stage, subsequent fatigue simulations can be stopped, and the simulation results of that stage can be used as input for risk assessment.

[0056] This embodiment establishes a continuous technical process for parametric simulation model establishment, ECC constitutive parameter calibration, interface connection parameter calibration, initial state data mapping, and phased vehicle fatigue degradation updates. This process enables the material response, interface connection state, existing initial effects, and fatigue degradation process of the continuous ECC-strengthened bridge deck structure to be continuously characterized in the same analysis flow, providing a simulation basis for subsequent risk value calculation, risk field generation, and determination of reinforcement optimization schemes.

[0057] Example 3 illustrates the risk field generation, dominant risk identification, reinforcement optimization scheme determination, and module implementation process of the bridge deck continuous ECC material reinforcement performance analysis method. This example can follow the parameter acquisition, parametric simulation model establishment, model calibration, initial state data import, and phased vehicle fatigue simulation results from the previous examples.

[0058] After completing the vehicle fatigue simulation for the kth fatigue stage or all fatigue stages, the simulation results are extracted from the bridge deck calculation unit, beam end calculation unit, ECC reinforcement layer calculation unit, and interface connection calculation unit. The simulation results include at least one of the following: ECC reinforcement layer tensile strain amplitude, ECC crack state, ECC fatigue damage variables, interface shear stress amplitude, interface slip amplitude, interface debonding length, interface fatigue damage variables, bridge deck deflection, beam end rotation angle, and relative displacement between adjacent beam ends. These simulation results are stored in association with the calculation unit number, node coordinates, or spatial location for subsequent risk value calculation and risk field generation.

[0059] The risk assessment results include at least one of the following: ECC reinforcement layer cracking risk, ECC fatigue damage risk, interface slip risk, and interface debonding risk. ECC reinforcement layer cracking risk can be determined based on the ECC reinforcement layer tensile strain, ECC tensile strength, ECC ultimate tensile strain, crack width, or crack development state; ECC fatigue damage risk can be determined based on ECC material fatigue damage variables, ECC material fatigue damage level, or ECC material stiffness reduction; interface slip risk can be determined based on the relationship between interface slip amplitude and interface slip control limit; and interface debonding risk can be determined based on interface debonding length, interface damage variables, or interface bond stiffness reduction.

[0060] The risk value is calculated according to the preset risk assessment rules. For each calculation unit, the risk components for ECC reinforcement layer cracking, ECC fatigue damage, interface slip, and interface debonding are determined. Risk values, risk components, risk thresholds, and weights can all be expressed using dimensionless parameters. Each risk component can be determined by the ratio between the corresponding response value and the allowable value, control value, or damage threshold. For example, the ECC reinforcement layer cracking risk component can be determined by the relationship between ECC tensile strain and ECC allowable tensile strain; the ECC fatigue damage risk component can be determined by the relationship between the ECC material fatigue damage variable and the ECC damage threshold; the interface slip risk component can be determined by the relationship between the interface slip amplitude and the interface slip control limit; and the interface debonding risk component can be determined by the relationship between the interface debonding length and the allowable debonding length or the debonding control value.

[0061] Each risk component can be determined as follows: ;

[0062] ; ; ;in : Risk component of ECC reinforcement layer cracking; ECC fatigue damage risk component; Interface slippage risk component; : Interface debonding risk component; ECC tensile strain or equivalent cracking control response; ECC allows for tensile strain; : Fatigue damage variables of ECC materials; ECC damage control limits; Interface sliding amplitude; Interface sliding control limits; : Interface debonding length; Allowable debonding length.

[0063] When a calculation unit exhibits only one primary degradation mode, the risk component corresponding to that degradation mode can be used as the risk value of that calculation unit. When a calculation unit exhibits multiple degradation modes simultaneously, the risk value of the calculation unit can be obtained by weighting the multiple risk components according to preset weights, or the maximum value among the multiple risk components can be used as the risk value of the calculation unit. Preset weights can be determined based on the design control objectives, inspection and evaluation results, material performance sensitivity, or engineering safety requirements of the bridge deck continuity zone. For example, when ECC crack control is the primary objective in the bridge deck continuity zone, the weights of the ECC reinforcement layer cracking risk component and the ECC fatigue damage risk component can be increased; when interface connection safety is the primary objective, the weights of the interface slip risk component and the interface debonding risk component can be increased. Specifically, the following methods can be adopted:

[0064] Calculate the overall risk value, where R is the risk value of the calculation unit. , , and These are the risk components for ECC reinforcement layer cracking, ECC fatigue damage, interface slip, and interface debonding, respectively, where w1 to w4 are non-negative weights and satisfy the following conditions: , ;

[0065] Alternatively, Determine the control risk value.

[0066] After obtaining the risk values ​​of each calculation unit, the risk assessment result is determined based on preset risk thresholds. The risk assessment result can be divided into low risk, medium risk, high risk, and severe risk. A risk value less than the first risk threshold is determined as low risk; a risk value greater than or equal to the first risk threshold but less than the second risk threshold is determined as medium risk; a risk value greater than or equal to the second risk threshold but less than the third risk threshold is determined as high risk; and a risk value greater than or equal to the third risk threshold is determined as severe risk. The first, second, and third risk thresholds increase sequentially and can be determined based on bridge structural design requirements, testing and evaluation standards, material test data, or engineering experience parameters. In one embodiment, both risk components and the overall risk value are represented by 0-1, and the first, second, and third risk thresholds can be set to 0.25, 0.50, and 0.75, respectively; when engineering specifications, testing and evaluation documents, or test plans have other control requirements, the thresholds converted from their corresponding limits shall prevail.

[0067] The risk field is formed by the risk values, risk assessment results, risk types, and spatial locations of each computational unit. Specifically, the unit number, node coordinates, risk value, risk level, and corresponding risk type of each computational unit can be correlated to obtain the spatialized risk distribution of the continuous bridge deck area. If the parametric simulation model and the risk display grid are consistent, the risk field can be directly formed according to the computational unit number; if the two grids are inconsistent, the risk values ​​of the computational units can be mapped to the risk display grid or the planar coordinates of the continuous bridge deck area through node coordinates, unit center coordinates, or spatial interpolation relationships. In this way, the risk field can represent the distribution of ECC reinforcement layer cracking risk, ECC fatigue damage risk, interface slip risk, and interface debonding risk at different spatial locations in the continuous bridge deck area.

[0068] The dominant risk type is determined based on the calculation units and their risk components that reach or exceed a preset risk threshold in the risk field. Within a given calculation unit, if the ECC reinforcement layer cracking risk component is the largest, then the ECC reinforcement layer cracking risk is determined as the dominant risk type for that calculation unit; if the ECC fatigue damage risk component is the largest, then the ECC fatigue damage risk is determined as the dominant risk type for that calculation unit; if the interface slip risk component is the largest, then the interface slip risk is determined as the dominant risk type for that calculation unit; if the interface debonding risk component is the largest, then the interface debonding risk is determined as the dominant risk type for that calculation unit. When two or more risk components reach high risk or severe risk, the calculation unit can be defined as a composite risk state, and the corresponding multiple risk types can be collectively used as the dominant risk type.

[0069] The location of risk distribution is determined based on the spatial location of the calculation unit that reaches or exceeds a preset risk threshold. Risk distribution locations may include areas near beam ends, the end areas of ECC reinforcement layers, the central area of ​​the bridge deck continuity zone, vehicle wheel track areas, areas affected by negative bending moments, weak interface connections, or a continuous distribution across multiple areas. By identifying the dominant risk type and risk distribution location, the correspondence between the causes of risk concentration and reinforcement parameters can be determined.

[0070] When generating reinforcement optimization schemes, at least one of the following parameters should be adjusted based on the dominant risk type and its location: ECC reinforcement thickness, ECC reinforcement length, and interface treatment parameters. If the dominant risk type is ECC reinforcement layer cracking risk, and the risk distribution is concentrated near the beam ends or in the negative bending moment influence area, the ECC reinforcement length can be increased first, or the ECC reinforcement thickness can be appropriately increased to improve the tensile deformation bearing capacity and crack control capacity of the bridge deck continuity area. If the dominant risk type is ECC fatigue damage risk, and the risk distribution is concentrated in the vehicle wheel track area or the middle of the bridge deck continuity area, the ECC reinforcement thickness can be increased first, or ECC material parameters with higher fatigue performance can be used to reduce the strain amplitude and fatigue damage accumulation rate of the ECC reinforcement layer under vehicle cyclic loading.

[0071] If the dominant risk type is interface slip risk, and the risk distribution is concentrated in the area near the end of the ECC reinforcement layer or the beam end, the interface roughness, roughening depth, adhesive shear strength, rebar spacing, or shear connector spacing can be adjusted first to improve the tangential connection between the ECC reinforcement layer and the existing bridge deck. If the dominant risk type is interface debonding risk, and the risk distribution is concentrated in the weak interface connection area or the area affected by negative bending moment, the adhesive type, adhesive coating thickness, adhesive tensile strength, adhesive shear strength, rebar diameter, rebar spacing, or shear connector spacing can be adjusted first to improve the interface tensile, shear, and debonding resistance. If the risk field shows that both the ECC reinforcement layer risk and the interface risk reach high risk or severe risk simultaneously, the ECC reinforcement thickness, ECC reinforcement length, and interface treatment parameters can be adjusted simultaneously.

[0072] After the reinforcement optimization scheme is generated, the adjusted ECC reinforcement parameters and interface processing parameters can be re-input into the parametric simulation model, and the model calculation, vehicle fatigue simulation, and risk field generation processes can be repeated. When the number of high-risk areas in the adjusted risk field decreases, the maximum risk value decreases, or all risk values ​​are below the preset risk threshold, the corresponding adjustment result is output as the reinforcement optimization scheme. If high-risk or severely risky areas still exist, the ECC reinforcement thickness, ECC reinforcement length, or interface processing parameters continue to be adjusted until the preset risk control requirements are met or the preset number of optimizations is reached. The preset risk control requirements can be determined based on the bridge structure design requirements, testing and evaluation requirements, fatigue life requirements, or engineering maintenance goals. As a specific optimization rule, the ECC reinforcement thickness can be increased step by step according to the preset thickness increment, and the ECC reinforcement length can be extended to the vicinity of the beam end or the negative bending moment influence area according to the preset length increment. The interface roughness, roughening depth, adhesive coating thickness, rebar spacing and shear connector spacing are adjusted step by step according to the allowable values ​​for construction. After each adjustment, the risk field is recalculated, and the reduction of the maximum risk value and the reduction of the number of high-risk calculation units are used as valid adjustment criteria.

[0073] In one embodiment, the preset thickness step, preset length step, and interface processing parameter adjustment step are determined by the design documents, allowable deviations in construction processes, or test verification results, respectively. If optimization reaches the preset number of optimizations but still cannot make all risk values ​​lower than the preset risk threshold, the solution corresponding to the current minimum and maximum risk values ​​is output and marked as a solution requiring manual review.

[0074] In terms of system implementation, the bridge deck continuous ECC material reinforcement performance analysis system includes a data acquisition module, a modeling and calibration module, an initial field processing module, a fatigue simulation module, and a risk optimization module. The data acquisition module acquires bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface processing parameters, load condition parameters, and field response data of the continuous bridge deck area, storing these data according to measurement point number, acquisition time, load condition number, or calculation unit number. The modeling and calibration module establishes a parametric simulation model including bridge deck calculation units, beam end calculation units, ECC reinforcement layer calculation units, and interface connection calculation units, and calibrates the ECC constitutive parameters and interface connection parameters sequentially using the field response data. The modeling and calibration module can include an ECC constitutive parameter calibration unit and an interface connection parameter calibration unit. The ECC constitutive parameter calibration unit determines the calibrated ECC constitutive parameters based on errors related to strain, crack width, and deflection. The interface connection parameter calibration unit determines the calibrated interface connection parameters based on errors related to interface slip, interface debonding length, and interface shear stress.

[0075] The initial field processing module applies temperature and beam end rotation conditions to the calibrated parametric simulation model, generating initial state data before vehicle fatigue and mapping this data to the vehicle fatigue simulation model. The fatigue simulation module performs vehicle fatigue simulation in stages according to the vehicle load spectrum, updating ECC material performance parameters and interface bonding performance parameters after each fatigue stage. Specifically, the fatigue simulation module determines the fatigue damage level of the ECC material based on the strain amplitude and fatigue cycle number of the ECC reinforcement layer calculation unit, and updates the ECC material stiffness and tensile strength accordingly. It also determines the interface fatigue damage level based on the interface slip amplitude, interface shear stress amplitude, and fatigue cycle number of the interface bonding calculation unit, and updates the interface bond stiffness and interface shear strength accordingly. The interface bond stiffness update includes at least one update of the interface normal stiffness and interface tangential stiffness, while the interface shear strength update uses an interface shear strength reduction factor corresponding to the interface fatigue damage level.

[0076] The risk optimization module receives updated simulation results from the fatigue simulation module, calculates the risk value and risk assessment results of each computational unit according to preset risk assessment rules, and generates a risk field based on the spatial location of the computational units. The risk optimization module also determines the dominant risk type and risk distribution location based on the risk field, and adjusts at least one of the ECC reinforcement thickness, ECC reinforcement length, and interface processing parameters according to the dominant risk type and risk distribution location to generate an optimized reinforcement scheme. The risk optimization module can feed back the optimized reinforcement scheme to the modeling and calibration module or the fatigue simulation module, enabling the system to perform a second simulation verification of the adjusted scheme.

[0077] This embodiment establishes a continuous technical relationship between vehicle fatigue simulation results, risk values, risk assessment results, risk fields, dominant risk types, risk distribution locations, and reinforcement optimization parameters. This process can correlate degradation forms such as ECC reinforcement layer cracking, ECC fatigue damage, interface slippage, and interface debonding with the spatial location of continuous areas on the bridge deck, providing a basis for targeted adjustments to ECC reinforcement thickness, ECC reinforcement length, and interface treatment parameters.

[0078] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for analyzing the reinforcement performance of continuous ECC materials for bridge decks, characterized in that, Includes the following steps: S1. Obtain bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface processing parameters, load condition parameters, and on-site response data of the continuous area of ​​the bridge deck. S2. Based on the obtained bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface processing parameters, and load condition parameters, establish a parametric simulation model of the continuous ECC reinforcement structure of the bridge deck. S3. First, calibrate the ECC constitutive parameters using the field response data of the continuous area of ​​the bridge deck, and then calibrate the interface connection parameters under the condition of fixed ECC constitutive parameters to obtain the calibrated parametric simulation model. Apply temperature conditions and beam end rotation conditions to the calibrated parametric simulation model to obtain the initial state data before vehicle fatigue. The initial state data includes the initial stress field, initial strain field, initial interface slip field and initial damage field. S4. Import the initial state data into the vehicle fatigue simulation model as the initial condition for vehicle fatigue simulation. Perform vehicle fatigue simulation according to the preset fatigue segmentation rules, and update the ECC material performance parameters and interface connection performance parameters after each fatigue stage. Based on the updated simulation results, the risk value and risk assessment results of each calculation unit are calculated according to the preset risk assessment rules, and a risk field is formed according to the spatial location of the calculation unit. Among them, the vehicle fatigue simulation in S4 is performed in stages, including the following steps: S41, the vehicle fatigue condition is divided into multiple fatigue stages according to the vehicle load spectrum, and each fatigue stage has a corresponding number of fatigue cycles and vehicle axle load combination. S42. After the kth fatigue stage ends, calculate the fatigue damage variable of the ECC material based on the ECC tensile strain amplitude, ECC fatigue allowable strain amplitude, and fatigue cycle number of the ECC reinforcement layer calculation unit during the kth fatigue stage; the ECC fatigue allowable strain amplitude is determined by the ECC material fatigue test data or ECC material design parameters. S43. Determine the fatigue damage level of ECC material based on the ratio of ECC tensile strain amplitude to ECC fatigue allowable strain amplitude, fatigue cycle number, and a preset ECC material fatigue damage level table. The preset ECC material fatigue damage level table includes multiple ECC material fatigue damage levels. Each ECC material fatigue damage level corresponds to an ECC material fatigue damage variable value range, an ECC material stiffness reduction factor, and an ECC tensile strength reduction factor. S44. Calculate the interface fatigue damage variables based on the interface shear stress amplitude, interface shear strength, interface slip amplitude, interface slip control limit, and fatigue cycle number of the interface connection calculation unit in the k-th fatigue stage. S45. Determine the interface fatigue damage level based on the ratio of interface shear stress amplitude to interface shear strength, the ratio of interface slip amplitude to interface slip control limit, the number of fatigue cycles, and a preset interface fatigue damage level table; the preset interface fatigue damage level table includes multiple interface fatigue damage levels, each interface fatigue damage level corresponds to an interface fatigue damage variable value range, an interface bond stiffness reduction factor, and an interface shear strength reduction factor. S46. Update the ECC material stiffness and ECC tensile strength based on the ECC material stiffness reduction factor and ECC tensile strength reduction factor corresponding to the fatigue damage level of the ECC material. S47. Update the interface bond stiffness and interface shear strength based on the interface bond stiffness reduction factor and interface shear strength reduction factor corresponding to the interface fatigue damage level. S48. The updated ECC material stiffness, ECC tensile strength, interface bond stiffness, and interface shear strength are used for vehicle fatigue simulation in the (k+1)th fatigue stage. S5. Based on the location of the calculation unit in the risk field where the risk value reaches or exceeds the preset risk threshold and its risk assessment results, determine the dominant risk type and risk distribution location, and select at least one from ECC reinforcement thickness, ECC reinforcement length and interface processing parameters for adjustment according to the dominant risk type and risk distribution location, and generate an adjusted reinforcement optimization scheme.

2. The method for analyzing the reinforcement performance of continuous ECC material for bridge decks according to claim 1, characterized in that, The interface connection parameters include interface normal stiffness, interface tangential stiffness, interface tensile strength, interface shear strength, interface fracture energy, and interface slip control limit. The interface slip control limit is the maximum allowable value of the relative slip of the interface under the condition that the interface connection performance meets the design requirements. The interface slip control limit is determined by interface shear test, interface pull-out test, bridge structural design documents or bridge deck continuous zone test and evaluation documents. The interface processing parameters include interface roughness, roughening depth, adhesive type, adhesive coating thickness, adhesive tensile strength, adhesive shear strength, rebar diameter, rebar spacing, and shear connector spacing.

3. The method for analyzing the reinforcement performance of continuous ECC material for bridge decks according to claim 1, characterized in that, The on-site response data for the continuous bridge deck area is data collected in the continuous structural area of ​​the bridge deck at adjacent beam ends. The on-site response data of the continuous area of ​​the bridge deck is stored in association according to the measuring point number, the time of collection, and the load condition number. The on-site response data of the continuous area of ​​the bridge deck includes structural deformation data, strain data, crack data, and interface response data; The structural deformation data includes deflection, vertical displacement, beam end rotation angle, and relative displacement between adjacent beam ends; The crack data includes crack width and crack location; The interface response data includes the interface slippage amount and the interface debonding length.

4. The method for analyzing the reinforcement performance of continuous ECC material for bridge decks according to claim 1, characterized in that, The parametric simulation model includes a bridge deck calculation unit, a beam end calculation unit, an ECC reinforcement layer calculation unit, and an interface connection calculation unit. The bridge deck calculation unit is used to characterize the stress and deformation of existing bridge decks; The beam end calculation unit is used to characterize the deformation of adjacent beam ends under temperature conditions, beam end rotation conditions, and vehicle load conditions. The ECC reinforcement layer calculation unit is used to characterize the tensile deformation, crack propagation state, and fatigue degradation state of the ECC reinforcement layer; The interface connection calculation unit is located between the bridge deck calculation unit and the ECC reinforcement layer calculation unit, and is used to characterize the bonding, slippage and debonding state between the ECC reinforcement layer and the existing bridge deck. The initial state data output by the parameterized simulation model of the calibrated bridge deck continuous ECC reinforcement structure is mapped to the bridge deck calculation unit, beam end calculation unit, ECC reinforcement layer calculation unit and interface connection calculation unit in the vehicle fatigue simulation model according to the unit number, node coordinates or spatial interpolation relationship. The physical meaning, spatial coordinates, and state variable definitions of computational units with the same name remain consistent in both the parametric simulation model and the vehicle fatigue simulation model.

5. The method for analyzing the reinforcement performance of continuous ECC material for bridge decks according to claim 1, characterized in that, The calibration of ECC constitutive parameters in S3 includes the following steps: S311. Based on the normalization error between simulated strain and field strain data, the normalization error between simulated crack width and field crack width, and the normalization error between simulated deflection and field deflection, construct the ECC constitutive error function. S312. Adjust the ECC constitutive parameters using a least squares iterative algorithm, particle swarm optimization algorithm, or genetic algorithm to reduce the value of the ECC constitutive error function; S313. When the ECC constitutive error function is less than or equal to the first convergence criterion value, stop adjusting the ECC constitutive parameters. S314. When the ECC constitutive error function is greater than the first convergence judgment value and the number of iterations reaches the first preset number, stop adjusting the ECC constitutive parameters and determine the ECC constitutive parameters at the time of stopping the adjustment as the calibrated ECC constitutive parameters. The ECC constitutive error function is obtained by weighting the normalized errors corresponding to simulated strain, simulated crack width, and simulated deflection according to preset weights.

6. The method for analyzing the reinforcement performance of continuous ECC material for bridge decks according to claim 5, characterized in that, The calibration interface connection parameters in S3 include the following steps: S321. Under the condition that the calibrated ECC constitutive parameters remain unchanged, construct the interface error function based on the normalized error between the simulated interface slip and the field interface slip, the normalized error between the simulated interface debonding length and the field interface debonding length, and the normalized error between the simulated interface shear stress and the reference shear stress value determined by the interface shear strength test value. S322. Adjust the interface connection parameters using the least squares iterative algorithm, particle swarm optimization algorithm, or genetic algorithm to reduce the value of the interface error function; S323. When the interface error function is less than or equal to the interface parameter calibration convergence judgment value, stop adjusting the interface connection parameters. S324. When the interface error function is greater than the interface parameter calibration convergence judgment value and the number of iterations reaches the second preset number, stop adjusting the interface connection parameters and determine the interface connection parameters at the time of stopping the adjustment as the calibrated interface connection parameters. The interface error function is obtained by weighting the normalized errors corresponding to the simulated interface slip, the simulated interface debonding length, and the simulated interface shear stress according to a preset weight.

7. A method for analyzing the reinforcement performance of continuous ECC material for bridge decks according to claim 5 or 6, characterized in that, The normalization error is determined by the ratio of the absolute value of the difference in the response data to the normalized reference value; Wherein, the absolute value of the difference in the response data is the absolute value of the difference between the simulation value and the reference value; The reference values ​​are either values ​​collected on-site or values ​​determined through testing. The normalization benchmark value is the maximum value among the absolute value of the reference value, the corresponding allowable limit value, and the preset minimum normalization value. The corresponding allowable limit is the limit set for this response data in the bridge structure design code, testing and evaluation code, or test plan; The preset minimum normalized value is a positive number determined based on the resolution of the measuring equipment, the minimum value of the field response data, or the minimum value of the test data.

8. A system for analyzing the reinforcement performance of continuous ECC materials for bridge decks, used to execute the method for analyzing the reinforcement performance of continuous ECC materials for bridge decks according to any one of claims 1-7, characterized in that, include: The data acquisition module is used to acquire bridge structural parameters, ECC reinforcement parameters, interface connection parameters, interface processing parameters, load condition parameters, and on-site response data of the continuous area of ​​the bridge deck. The modeling and calibration module is used to establish a parametric simulation model including bridge deck calculation units, beam end calculation units, ECC reinforcement layer calculation units, and interface connection calculation units. It also uses field response data to calibrate the ECC constitutive parameters and interface connection parameters in sequence to obtain the calibrated simulation model. The initial field processing module is used to apply temperature and beam end rotation conditions to the calibrated simulation model, and generate and map the initial state data of the vehicle before fatigue. The fatigue simulation module is used to perform fatigue simulation in stages according to the vehicle load spectrum, and update the ECC material performance parameters and interface connection performance parameters after each fatigue stage. The risk optimization module is used to generate a risk field based on the vehicle fatigue simulation results, determine the dominant risk type and risk distribution location based on the risk field, adjust at least one of the ECC reinforcement thickness, ECC reinforcement length and interface processing parameters, and generate a reinforcement optimization scheme.

9. The bridge deck continuous ECC material reinforcement performance analysis system according to claim 8, characterized in that, The modeling and calibration module includes an ECC constitutive parameter calibration unit and an interface connection parameter calibration unit. The ECC constitutive parameter calibration unit is used to construct an ECC constitutive error function based on the normalization error between simulated strain and field strain data, the normalization error between simulated crack width and field crack width, and the normalization error between simulated deflection and field deflection. It also adjusts at least one of the following parameters to obtain the calibrated ECC constitutive parameters: ECC elastic modulus, ECC tensile strength, ECC ultimate tensile strain, tensile hardening segment parameters, and post-cracking stiffness degradation parameters. The interface connection parameter calibration unit is used to construct an interface error function based on the normalized error between the simulated interface slip and the in-situ interface slip, the normalized error between the simulated interface debonding length and the in-situ interface debonding length, and the normalized error between the simulated interface shear stress and the reference shear stress value determined by the interface shear strength test value, while keeping the calibrated ECC constitutive parameters unchanged. It then adjusts the interface normal stiffness, interface tangential stiffness, interface tensile strength, interface shear strength, and interface fracture energy to obtain the calibrated interface connection parameters. The interface slip control limit is used as a constraint parameter for error normalization, fatigue damage calculation, and risk assessment in determining the calibration results. The fatigue simulation module is used to determine the fatigue damage level of the ECC material based on the strain amplitude and fatigue cycle number of the ECC reinforcement layer calculation unit after each fatigue stage, and to update the stiffness and tensile strength of the ECC material based on the fatigue damage level of the ECC material; it also determines the interface fatigue damage level based on the interface slip amplitude, interface shear stress amplitude and fatigue cycle number of the interface connection calculation unit, and updates the interface bond stiffness and interface shear strength based on the interface fatigue damage level, wherein the update process uses the corresponding stiffness reduction factor and strength reduction factor respectively.

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