Prestressed beam bridge creep-corrosion-hydrodynamic fatigue coupled deformation calculation and life evaluation method and device, and storage medium

Abstract

The invention relates to a creep-corrosion-hydrodynamic fatigue coupled deformation calculation and life evaluation method and device for a prestressed beam bridge, and a storage medium. The method comprises the following steps: establishing a beam bridge hydrodynamic simulation model containing a time-varying creep constitutive structure and prestressed tendons; parameters such as concrete creep, prestress relaxation, prestressed tendon corrosion depth and hydrodynamic fatigue cracking depth are updated year by year, the failure area of prestressed tendons is determined based on a corrosion and fatigue competition criterion, and the interface bonding performance is calculated. Then hydrodynamic force and long-term effect coupling simulation is carried out, mid-span deflection, relative displacement of piers and prestress amplitude are extracted, and then the corrosion-hydrodynamic force fatigue life of the prestressed tendons is evaluated. And iteratively calculating until the mid-span deflection, the service life or the fatigue life reaches a critical value, and outputting a deformation time-history curve. Compared with the prior art, the method has the advantages that the hydrodynamic accumulated displacement fatigue effect and the multi-factor coupling effect are considered, the minimum service duration is determined through multiple failure modes, and the actual situation can be comprehensively represented.

Description

Technical Field

[0001] This invention relates to a method for calculating the long-term deformation of prestressed beam bridges using a multi-factor coupled approach, and particularly to a method, equipment, and storage medium for calculating the deformation and assessing the lifespan of prestressed beam bridges using a creep-corrosion-hydraulic fatigue coupled approach. Background Technology

[0002] Prestressed concrete beam bridges, as a core component of modern transportation infrastructure, are widely used in water-related environments such as river and sea crossings. However, during long-term service, these bridges are continuously subjected to multiple effects, including hydrodynamic forces, vehicle loads, and environmental erosion (such as chloride ion corrosion), leading to degradation effects such as concrete creep, prestressing tendon corrosion, and hydrodynamic fatigue. The coupled effects of these factors result in prestressing tendon failure and concrete-prestressing tendon interface degradation, which in turn causes structural performance degradation, increased mid-span deflection, and even induces deformation exceeding limits or collapse accidents. Therefore, there is an urgent need for an accurate long-term deformation calculation method to assess the deformation evolution of key sections, provide a theoretical basis for bridge maintenance, reinforcement, and performance improvement, and ensure high-quality service throughout their entire life cycle.

[0003] Existing methods for long-term performance evaluation of prestressed concrete bridges often focus on single-factor analysis, lacking a systematic consideration of multiple coupling effects. For example, existing technology CN120337367A (A Time-Varying Reliability Evaluation Method for Large-Span Box Girder Bridges Considering Concrete Fatigue Creep) discloses a method that constructs a unified constitutive model by calculating static creep of concrete, fatigue creep caused by vehicle loads, and shrinkage strain, and uses an importance sampling method for reliability evaluation. Although this method introduces the effect of concrete fatigue creep, it only focuses on creep behavior under vehicle loads and does not address key issues such as hydrodynamic effects in wading environments, corrosion of prestressed tendons, and reciprocating motion of prestressed tendons caused by hydrodynamic fatigue. Its limitation lies in its inability to simulate the accelerated failure process of prestressed tendons under the coupled effects of hydrodynamics and corrosion.

[0004] On the other hand, existing technology CN115408754A (A method for analyzing the dynamic fatigue performance of composite beam bridges considering time-varying effects) focuses on steel-concrete composite beam bridges. It analyzes the impact of time-varying effects (such as concrete creep) on the fatigue damage of the lower flange and end studs of the mid-span steel beam by establishing a vehicle-bridge coupled model. While this method considers fatigue performance under dynamic loads, it is mainly applicable to composite beam bridge structures and does not cover the corrosion-hydraulic fatigue coupling mechanism of prestressed tendons in prestressed concrete beam bridges. Especially for bridges navigating water, the longitudinal relative movement of adjacent piers caused by hydrodynamic forces leads to cyclic stress in the prestressed tendons, and existing methods fail to quantify the cross-sectional degradation law under the synergistic effect of hydrodynamic fatigue and corrosion.

[0005] In summary, existing technologies all have significant shortcomings: they lack a systematic analytical method for the triple coupling effect of concrete creep, prestressing tendon corrosion, and hydrodynamic fatigue in prestressed concrete beam bridges in water-crossing areas. This leads to large deviations in long-term deformation prediction and fails to accurately reflect the failure path of prestressing tendons under coupled effects.

[0006] Therefore, developing an effective method for calculating the long-term deformation of prestressed beam bridges that integrates the coupling effects of creep, corrosion, and hydrodynamic fatigue has become a key issue in solving the aforementioned technical bottlenecks. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of the prior art by providing a method, equipment, and storage medium for deformation calculation and life assessment of prestressed beam bridges based on creep-corrosion-hydrodynamic fatigue coupling. This invention considers the cumulative displacement fatigue effect of hydrodynamics and the coupling effect of multiple factors, and determines the minimum service life of multiple failure modes. It can comprehensively characterize the actual situation and fill the gap in the prior art.

[0008] The objective of this invention can be achieved through the following technical solutions: The first aspect of this invention provides a method for deformation calculation and life assessment of prestressed beam bridges under creep-corrosion-hydraulic fatigue coupling, comprising the following steps: S1. Establish a hydrodynamic simulation model of a beam bridge containing time-varying creep constitutive structures and prestressed tendons; S2, Regarding the current service year t First, concrete creep, prestress relaxation, corrosion depth increment of prestressing tendons, and fatigue cracking depth increment of prestressing tendons hydrodynamic reciprocating downward are calculated. Then, the failure depth of prestressing tendons is determined based on the competition criterion of corrosion and fatigue cracking, and its failure area is calculated. Next, the interface bond stress and interface spring stiffness are calculated, and the long-term performance influence parameters of concrete and prestressing tendons in the hydrodynamic simulation model of beam bridge are updated. S3. Based on the updated parameters from S2 and the hydrodynamic simulation model of the beam bridge, perform hydrodynamic and long-term effect loading simulation analysis, and extract the mid-span deflection. f The longitudinal relative displacement between adjacent piers and the prestress amplitude were calculated, along with the corrosion-hydraulic coupled fatigue life of the prestressing tendons. T fatigue ; S4. Based on the simulation results of S3, determine whether the mid-span deflection has reached the critical deformation. f th Has the current service life reached the critical age limit? T th Or whether the prestressed tendon corrosion-hydraulic coupling fatigue life has been reached. T fatigue The service duration shall be determined based on the first of the three events. S5. Increment the service year t to t+1, repeat steps S2 to S4 until the exit condition is met, and output the deformation time curve.

[0009] Furthermore, in S1, the specific process of establishing a hydrodynamic simulation model of a beam bridge containing time-varying creep constitutive structures and prestressed tendons includes: Based on the structural parameters, hydrological information, and drawings of water-crossing bridges, the geometric parameters, fluid domain dimensions, material properties, and constraint conditions of prestressed beam bridges are obtained. A three-dimensional numerical model containing the main body of the prestressed beam bridge and the fluid domain is established. The prestressed beam bridge is discretized into a solid element mesh, and the fluid domain is configured with incident flow velocity, boundary conditions, and initial hydrostatic pressure field. The time-varying creep constitutive relation, prestressed tendon constitutive relation, cross-sectional geometric parameters, and interface bond-slip constitutive relation are defined in the model. The inlet velocity condition, outlet flow condition, bottom no-slip boundary, and top non-reflective boundary of the fluid domain are configured to complete the construction of the hydrodynamic simulation model of the beam bridge.

[0010] Furthermore, in S2, the specific process for calculating concrete creep, prestress relaxation, prestressing tendon corrosion depth increment, and prestressing tendon hydrodynamic reciprocating fatigue cracking depth increment includes: Based on the time-varying law of the elastic modulus of concrete and the creep coefficient, the creep deformation of concrete under continuous load is calculated. Then, considering the relaxation effect of the prestressing tendons, the amount of prestress loss over time is calculated; Furthermore, based on the concrete protective layer thickness, water-cement ratio, and pitting coefficient, the annual corrosion depth increment of the prestressed tendons is calculated by integration. Meanwhile, based on the relative displacement data of adjacent piers caused by hydrodynamic action and the fatigue crack propagation coefficient, the fatigue crack depth increment of prestressed tendons under reciprocating displacement is calculated.

[0011] Furthermore, in S2, the specific process of determining the failure depth of the prestressed tendon based on the competition criterion of corrosion and fatigue cracking, and then calculating its failure area, includes: First, compare the increase in corrosion depth of prestressed tendons with the increase in fatigue cracking depth within the same year, and take the larger of the two as the failure depth increase for that year. Then, the failure depth increment of this year is added to the cumulative failure depth of the previous year to obtain the total failure depth of the current year; Furthermore, based on the relative relationship between the failure depth and the prestressing tendon diameter, different geometric calculation methods are used to determine the failure area. When the failure depth does not exceed the critical value, the failure area is calculated by piecewise integration. When it exceeds the critical value, the loss is calculated based on the loss of the complete section.

[0012] Furthermore, in S2, the specific process of calculating the interfacial bond stress and interfacial spring stiffness, and updating the long-term performance influence parameters of concrete and prestressed tendons in the hydrodynamic simulation model of the beam bridge includes: Based on the stress state, failure depth, and anchorage length of the prestressing tendons, calculate the bond stress distribution between the concrete and the prestressing tendons. Then, based on the elastic modulus of the prestressed tendons and the cross-sectional area loss, the interface spring stiffness coefficient is calculated; Then, the calculated bond stress, spring stiffness, and updated material parameters are input into the hydrodynamic simulation model of the beam bridge.

[0013] Furthermore, in S3, based on the updated parameters from S2 and the hydrodynamic simulation model of the beam bridge, hydrodynamic and long-term effect loading simulation analysis is performed, and the mid-span deflection is extracted. f The longitudinal relative displacement between adjacent piers and the prestress amplitude were calculated, along with the corrosion-hydraulic coupled fatigue life of the prestressing tendons. T fatigue The specific process includes: Input the updated concrete creep parameters, prestressed tendon section parameters, and interface bond parameters from S2 into the hydrodynamic simulation model of the beam bridge; Then, the fluid domain incident velocity mode is set, and long-term effect loads such as the bridge's self-weight dead load are applied. Then, hydrodynamic-structural coupled simulation calculations were performed to extract the deflection value at the mid-span section. f、 Time history data of longitudinal relative displacement between adjacent bridge piers; Simultaneously, based on the relative displacement data, the stress amplitude of the prestressing tendons is calculated. Combined with the prestressing tendon failure depth data obtained from S2, the corrosion-hydraulic coupled fatigue life of the prestressing tendons is obtained through the fatigue life calculation formula. T fatigue .

[0014] Furthermore, in S4, it is determined whether the mid-span deflection has reached the critical deformation. f th Has the current service life reached the critical age limit? T th Or whether the prestressed tendon corrosion-hydraulic coupling fatigue life has been reached. T fatigue The service duration is determined based on the first of the three events, and the specific process includes: Compare current mid-span deflection f With preset critical deformation f th The size relationship is recorded, and the service life at which the critical deformation is reached is recorded. T 1 ; Then, compare the current service life t with the preset critical service life.T th The size relationship is recorded, and the service life that has reached the critical service life is recorded. T 2 ; Furthermore, the current service life t is compared with the corrosion-hydraulic coupled fatigue life of the prestressed tendons. T fatigue The size relationship is recorded, along with the service life at which fatigue life is reached. T 3 ; Finally, take T 1 、T 2 、T 3 The minimum value in the range is taken as the final service life of the structure.

[0015] Furthermore, in S5, the service year t is incremented to t+1, and steps S2 to S4 are repeated until the exit condition is met, outputting the deformation time curve. The specific process includes: Increase the current service year t by 1 year to use as the new calculation year; The parameter update process was repeated according to S2, including concrete creep calculation, prestressed tendon failure depth calculation, and interface parameter update. Then, based on the updated parameters, S3 simulation analysis is performed to obtain deformation and life data for the new year; Next, the judgment criteria of S4 are used to check whether any exit condition is met. The exit conditions include reaching critical deformation, reaching critical lifespan, and reaching fatigue life. If the exit condition is not met, continue executing S2 to S4 in a loop; If any exit condition is met, the calculation terminates and the output is a deformation-time curve containing the mid-span deflection values ​​for each year.

[0016] A second aspect of the present invention provides an electronic device, including a memory and a processor, wherein the processor is used to execute a program in the memory to realize the deformation calculation and life assessment method for the coupling of creep-corrosion-hydraulic fatigue in prestressed beam bridges as described above.

[0017] A third aspect of the present invention provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform the deformation calculation and life assessment method for the creep-corrosion-hydraulic fatigue coupling of prestressed beam bridges as described above.

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention determines the failure depth of prestressed tendons and updates the prestressed tendon area in the simulation model through a competition criterion. It comprehensively considers multiple actions and their coupled effects of creep, corrosion, and hydrodynamic fatigue. This invention can accurately calculate and predict the long-term deformation and performance of prestressed beam bridges, providing a reference for maintenance, reinforcement, and performance improvement, ensuring long-term high-quality service. Furthermore, this invention considers the reciprocating motion fatigue of prestressed tendons caused by the longitudinal relative movement of adjacent piers due to hydrodynamic effects, filling a gap in research on this aspect of bridges across water and ensuring structural safety. Compared with methods based on single-factor influence or failure modes, this invention considers multiple actions and their coupling effects and determines the minimum service life from multiple failure modes, improving structural safety margin and preventing sudden safety accidents. Attached Figure Description

[0019] Figure 1 Flowchart of a multi-factor coupled long-term deformation calculation method for prestressed beam bridges; Figure 2 This is a typical overview of a bridge. Figure 3 This is a structural diagram of prestressed tendons; Figure 4 For the hydrodynamic simulation model of the beam bridge; Figure 5 The prestressed tendons are hydrodynamically reciprocated. Figure 6 Calculation diagram of the failure interface; Figure 7 The deformation time curve at mid-span and the effects of creep, corrosion, and hydrodynamic fatigue are shown. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, circuit structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0021] Example 1 The method for calculating the coupled deformation and assessing the life of prestressed beam bridges based on creep, corrosion, and hydrodynamic fatigue in this embodiment includes: Step S1: Establish a hydrodynamic simulation model of a beam bridge containing time-varying creep constitutive structures and prestressed tendons, including prestressed beam bridge, fluid domain, material properties and constraints; Step S2: Current Year of Service tThe calculation includes concrete creep, prestress relaxation, corrosion depth increment of prestressed tendons, fatigue cracking depth increment of prestressed tendons due to hydrodynamic reciprocating displacement, determination of prestressed tendon failure depth and calculation of failure area based on the competition criterion of corrosion and fatigue cracking, calculation of interface bond stress and interface spring stiffness coefficient based on failure depth and failure area, and updating of parameters affecting the long-term performance of concrete and prestressed tendons. Step S3: Current Year of Service t Based on the model and updated parameters, hydrodynamic and long-term effects loading simulation analysis was carried out, and the mid-span deflection was extracted and calculated. f、 Longitudinal relative displacement between adjacent piers, prestress amplitude, corrosion-hydraulic coupled fatigue life of prestressing tendons T fatigue ; Step S4: Determine whether the mid-span deflection has reached the critical deformation. f th Has the current service life reached the critical age limit? T th (Preset calculation period or design period, etc.), whether the current service life has reached the corrosion-hydraulic coupling fatigue life of the prestressed tendons. T fatigue The criterion is which of the three first reaches the critical point; Step S5: Year of Service t = t +1, repeat steps S2, S3, and S4 until the exit condition or condition is met, service year. t Exit directly and output the deformation time curve.

[0022] The coupling effect includes concrete creep, prestress relaxation, prestressing tendon corrosion section loss, prestressing tendon hydrodynamic back-and-forth fatigue cracking, and concrete-prestressing tendon interface degradation. Specifically, the larger of the prestressing tendon corrosion depth increment and the prestressing tendon hydrodynamic back-and-forth fatigue cracking depth increment (competition criterion) for each service year is used as the prestressing tendon failure depth increment for the current service year. The prestressing tendon failure depth for the current service year is the increment plus the prestressing tendon failure depth for the previous service year. Coupling is achieved by updating the prestressing tendon area in the simulation model.

[0023] The aforementioned judgment criteria consider three failure modes: structural deformation, structural service life, and corrosion-hydraulic coupled fatigue of prestressing tendons. The service life is determined based on the first occurrence of these modes, i.e., the minimum service life. The specific mathematical formula is as follows: in: The service life is obtained from the critical deformation reached by the mid-span deflection. The service duration is the length of service obtained when the previous service years have reached the critical service life. The service life is the length of time obtained by reaching the corrosion-hydraulic coupling fatigue life of the prestressed tendons at the current service life.

[0024] The mathematical expression for calculating the fatigue cracking depth increment of the prestressed tendon during hydrodynamic reciprocating downward displacement is as follows: in: and Years of service i +1 Prestressed tendon hydrodynamic repositioning fatigue crack depth increment and service years i The depth of fatigue cracking due to hydrodynamic displacement of prestressed tendons towards reset. The number of cycles of relative motion between adjacent bridge piers along the bridge direction under hourly hydrodynamic action. denoted as the metal fatigue crack propagation coefficient. Pi The equivalent displacement amplitude of the longitudinal relative displacement of adjacent bridge piers under hourly hydrodynamic action. This refers to the elastic modulus of the prestressed tendon.

[0025] The specific principle for determining the failure depth of prestressed tendons based on the competitive criterion of corrosion and fatigue cracking is: service years t +1 represents the failure depth of the prestressed tendon, which is equal to the service years. t The depth of prestressed tendon failure plus the years of service t The larger of the corrosion depth increment (+1) and the fatigue cracking depth increment due to dynamic relocation is mathematically expressed as: in: and Years of service i +1 and i Prestressed tendon failure depth The thickness of the concrete protective layer. Water-cement ratio, The coefficient is 1 for uniform corrosion and 4 for pitting corrosion.

[0026] The interfacial bond stress and interfacial spring stiffness take into account the effects of the prestressing tendon failure depth and failure area, and are continuously updated during the model analysis. The mathematical expression is as follows: in: For interfacial bonding stress, The average tensile force of the prestressing tendons. The effective diameter of the prestressing tendon. This is the anchorage length of the prestressed tendons, usually taken as half the span length. For the interface spring stiffness, and These are the initial effective area and service years of the prestressing tendons, respectively. i Area of ​​prestressed tendon failure.

[0027] The formula for calculating the failure area is: in: The critical depth of prestressed tendon failure is taken as half the diameter. The coordinates and intervals along the failure depth are... .

[0028] The hydrodynamic simulation model of the beam bridge includes a prestressed beam bridge, a fluid domain, material properties and constraints, and can update the time-varying creep constitutive model of concrete, the constitutive model of prestressed tendons and the cross-sectional geometric parameters (diameter, cross-sectional area), the prestress relaxation constitutive model, and the bond-slip constitutive model of the concrete-prestressed tendon interface.

[0029] The hydrodynamic and long-term effects loading simulation analysis is conducted by setting the incident flow velocity and mode in the fluid domain and considering dead loads such as the bridge's self-weight, thus achieving the consideration of dynamic and long-term effects.

[0030] Application Example 1 A method for calculating and assessing the coupled deformation and lifespan of prestressed beam bridges based on creep, corrosion, and hydrodynamic fatigue, with the following workflow: Figure 1 As shown, it includes: Step S1: Establish a hydrodynamic simulation model of a beam bridge containing time-varying creep constitutive structures and prestressed tendons; Based on the bridge structure, hydrological information, or drawings, obtain the geometric parameters, material properties, constitutive parameters, and constraints of the structure, fluid domain, and prestressed tendons to establish a three-dimensional hydrodynamic simulation model of the beam bridge. Bridge structural design: simply supported continuous system, with continuous spans arranged at 15m+15m intervals, piers 7m high, cap beams 1m high, and beam height 1.78m. Figure 2 As shown; the continuous span across the water utilizes prestressed reinforced concrete continuous T-beams. Each bridge segment consists of four T-beams, each 1600 mm wide, connected laterally by 810 mm wide wet joints. The T-beam web thickness is 300 mm, the height is 1500 mm, and the top plate thickness is 280 mm; all transverse diaphragms have a longitudinal thickness of 200 mm; the mid-span transverse diaphragms have rectangular gaps of 1310 mm × 800 mm. Prestressing tendons: Three prestressed steel strands are used to apply prestress to the T-beams. Post-tensioning involves the use of corrugated pipes and anchorages. After tensioning, the pipes are grouted, such as... Figure 3 As shown; the nominal diameter of the steel strand is 15.24 mm, and the effective cross-sectional area is 140 mm². 2 Tensile stress σ con The pressure is 1395 MPa, which is 75% of the standard yield strength (1860 MPa). Fluid domain: Located in a flood-prone area with high flow velocity.

[0031] Establish a hydrodynamic simulation model of the bridge's beams, such as... Figure 4 As shown, a numerical fluid domain measuring 40 meters long, 35 meters wide, and 6 meters high was established, along with a bridge structure model, with its leading edge 10 meters from the inlet. The boundary conditions for the numerical fluid domain were configured as follows: the bottom and sidewalls were set as no-slip boundaries; a velocity inlet condition was applied at the inlet to control the inflow; an outflow condition was used at the outlet to allow free flow; and the top boundary was treated as a non-reflective boundary to minimize wave reflection. Initial velocities were assigned to all grid nodes within the water area. v 0 and the initial hydrostatic pressure field. The structural model is discretized into a mesh of 15,100 solid elements, with an element size of 0.2 meters.

[0032] Step S2: Current Year of Service t The calculation includes concrete creep, prestress relaxation, corrosion depth increment of prestressed tendons, fatigue cracking depth increment of prestressed tendons due to hydrodynamic reciprocating displacement, determination of prestressed tendon failure depth and calculation of failure area based on the competition criterion of corrosion and fatigue cracking, calculation of interface bond stress and interface spring stiffness coefficient based on failure depth and failure area, and updating of parameters affecting the long-term performance of concrete and prestressed tendons. Concrete creep is calculated as follows: In the formula, and These are strain and stress, The elastic modulus of concrete during pouring. The elastic modulus of concrete 28 days after pouring. It is the creep coefficient, which can be determined by calculation according to the standard.

[0033] The prestress relaxation calculation is as follows: In the formula, The relaxation function is the time-varying stiffness, which is automatically calculated and considered by the element.

[0034] Calculation of corrosion depth increment of prestressed tendons: In the formula, The water-cement ratio is set to 0.40. The thickness of the concrete protective layer is 50 mm.

[0035] Calculation of fatigue crack depth increment during hydrodynamic repositioning of prestressed tendons: in: and Years of service i +1 Prestressed tendon hydrodynamic repositioning fatigue crack depth increment and service years i The depth of fatigue cracking due to hydrodynamic displacement of prestressed tendons towards reset. The number of cycles of relative motion between adjacent bridge piers along the bridge direction under hourly hydrodynamic action, from Figure 5 The curves shown were obtained statistically. The equivalent displacement amplitude of the longitudinal relative displacement of adjacent bridge piers under hourly hydrodynamic action, from Figure 5 The curves shown were obtained statistically. The elastic modulus of the prestressed tendon is taken as 195 GPa. Let be the fatigue crack propagation factor for metals, taken as 4.1 × 10⁻⁶. -12 , Pi is the mathematical constant of a circle.

[0036] Years of service t +1 The failure depth of the prestressed tendon is determined by the year of service. t The depth of prestressed tendon failure plus the years of service t The larger of the corrosion depth increment (+1) and the fatigue crack depth increment due to dynamic relocation is calculated as follows: in: and Divided by service year i +1 and i Prestressed tendon failure depth The thickness of the concrete protective layer. Water-cement ratio, The coefficients are: pitting coefficient (1) and uniform corrosion coefficient (4).

[0037] The failure area is calculated as follows: in: The critical depth of prestressed tendon failure is taken as half the diameter. The coordinates and intervals along the failure depth are... .

[0038] Concrete-prestressed tendon interface bond stress and interface spring stiffness, The calculation is as follows: in: The average tensile force of the prestressing tendons is determined based on simulation results. The effective diameter of the prestressing tendon is equal to the nominal diameter of 15.24 mm. The anchorage length of the prestressed tendon is taken as 7.5m. The initial effective area of ​​the prestressing tendon is equal to the effective cross-sectional area of ​​140 mm². 2 .

[0039] Step S3: Current Year of Service t Based on the model and updated parameters, hydrodynamic and long-term effects loading simulation analysis was carried out, and the mid-span deflection was extracted and calculated. f、 Longitudinal relative displacement between adjacent piers, prestress amplitude, corrosion-hydraulic coupled fatigue life of prestressing tendons T fatigue ; Update the parameters affecting the long-term performance of concrete and prestressed tendons in the bridge hydrodynamic simulation model, conduct hydrodynamic and long-term effect loading simulation analysis, and extract and calculate the mid-span deflection. f、 Longitudinal relative displacement between adjacent piers, prestress amplitude, corrosion-hydraulic coupled fatigue life of prestressing tendons T fatigue .

[0040] The prestress amplitude can be calculated by multiplying the longitudinal relative displacement between adjacent piers by the elastic modulus of the prestressing tendons.

[0041] The fatigue life calculation for corrosion-hydraulic coupling of prestressed tendons is as follows: Step S4: Determine whether the mid-span deflection has reached the critical deformation. f th Has the current service life reached the critical age limit? T th (Preset calculation period or design period, etc.), whether the current service life has reached the corrosion-hydraulic coupling fatigue life of the prestressed tendons. T fatigue The criterion is which of the three first reaches the critical point.

[0042] The minimum service life is calculated as follows: Step S5: Year of Service t = t +1, repeat steps S2, S3, and S4 until the exit condition or condition is met, service year. t Exit directly and output the deformation time curve.

[0043] Example 2 This invention provides an electronic device, including a memory and a processor. The processor executes a program in the memory to implement the aforementioned method for deformation calculation and life assessment of prestressed beam bridges involving creep-corrosion-hydraulic fatigue coupling. The program details the complete algorithm flow of the aforementioned method for deformation calculation and life assessment of prestressed beam bridges involving creep-corrosion-hydraulic fatigue coupling, including establishing a hydrodynamic simulation model of the beam bridge with time-varying creep constitutive structure, calculating the failure depth of prestressing tendons and updating parameters based on a competition criterion, performing hydrodynamic and long-term effect loading simulation analysis, and multi-mode criticality judgment. The processor executes the program to automatically iteratively calculate and generate the bridge deformation time curve and determine the service life, thereby providing an efficient and reliable life assessment tool for practical engineering projects.

[0044] The processor can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application-Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. The memory may include Random Access Memory (RAM) and may also include Non-Volatile Memory, such as at least one disk storage device. The memory can be internal memory of the Random Access Memory (RAM) type. The processor and memory can be integrated into one or more independent circuits or hardware, such as an Application-Specific Integrated Circuit (ASIC). It should be noted that when the computer program in the above-mentioned memory is implemented in the form of software functional units and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0045] Example 3 This invention provides a storage medium containing computer-executable instructions. When executed by a computer processor, the storage medium performs the deformation calculation and life assessment method for the coupled creep-corrosion-hydraulic fatigue of prestressed beam bridges, as described above. The stored computer-executable instructions are configured to: first, establish a hydrodynamic simulation model of the beam bridge including time-varying creep constitutive structures and prestressing tendons; then, iteratively calculate concrete creep, the increment of prestressing tendon corrosion depth, and the increment of fatigue cracking depth; update the prestressing tendon failure parameters based on a competition criterion; next, perform coupled simulation analysis of hydrodynamics and long-term effects; and finally, output the bridge deformation-time curve based on the critical judgment of three failure modes: mid-span deflection, service life, and fatigue life, thereby achieving accurate life assessment of prestressed beam bridges under the coupled effects of multiple factors.

[0046] Storage media can be electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems or propagation media. Storage media can also include semiconductor or solid-state memory, magnetic tape, removable computer disks, random access memory (RAM), read-only memory (ROM), hard disks, and optical discs. Optical discs can include optical disc-read-only memory (CD-ROM), optical disc-read / write (CD-RW), and DVDs.

[0047] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for deformation calculation and life assessment of prestressed beam bridges under creep-corrosion-hydraulic fatigue coupling, characterized in that, Includes the following steps: S1. Establish a hydrodynamic simulation model of a beam bridge containing time-varying creep constitutive structures and prestressed tendons; S2, Regarding the current service year t First, concrete creep, prestress relaxation, corrosion depth increment of prestressing tendons, and fatigue cracking depth increment of prestressing tendons hydrodynamic reciprocating downward are calculated. Then, the failure depth of prestressing tendons is determined based on the competition criterion of corrosion and fatigue cracking, and its failure area is calculated. Next, the interfacial bond stress and interfacial spring stiffness are calculated, and the long-term performance influence parameters of concrete and prestressing tendons in the hydrodynamic simulation model of beam bridge are updated. S3. Based on the updated parameters from S2 and the hydrodynamic simulation model of the beam bridge, perform hydrodynamic and long-term effect loading simulation analysis, and extract the mid-span deflection. f The longitudinal relative displacement between adjacent piers and the prestress amplitude were calculated, along with the corrosion-hydraulic coupled fatigue life of the prestressing tendons. T fatigue ; S4. Based on the simulation results of S3, determine whether the mid-span deflection has reached the critical deformation. f th Has the current service life reached the critical age limit? T th Or whether the prestressed tendon corrosion-hydraulic coupling fatigue life has been reached. T fatigue The service duration shall be determined based on the first of the three events. S5. Increment the service year t to t+1, repeat steps S2 to S4 until the exit condition is met, and output the deformation time curve.

2. The method for deformation calculation and life assessment of prestressed beam bridges based on creep-corrosion-hydraulic fatigue coupling as described in claim 1, characterized in that, In S1, the specific process of establishing a hydrodynamic simulation model of a beam bridge containing time-varying creep constitutive structures and prestressed tendons includes: Based on the structural parameters, hydrological information, and drawings of water-crossing bridges, the geometric parameters, fluid domain dimensions, material properties, and constraint conditions of prestressed beam bridges are obtained. A three-dimensional numerical model containing the main body of the prestressed beam bridge and the fluid domain is established. The prestressed beam bridge is discretized into a solid element mesh, and the fluid domain is configured with incident flow velocity, boundary conditions, and initial hydrostatic pressure field. The time-varying creep constitutive relation, prestressed tendon constitutive relation, cross-sectional geometric parameters, and interface bond-slip constitutive relation are defined in the model. The inlet velocity condition, outlet flow condition, bottom no-slip boundary, and top non-reflective boundary of the fluid domain are configured to complete the construction of the hydrodynamic simulation model of the beam bridge.

3. The method for deformation calculation and life assessment of prestressed beam bridges based on creep-corrosion-hydraulic fatigue coupling as described in claim 1, characterized in that, In S2, the specific process for calculating concrete creep, prestress relaxation, prestressing tendon corrosion depth increment, and prestressing tendon hydrodynamic reciprocating fatigue cracking depth increment includes: Based on the time-varying law of the elastic modulus of concrete and the creep coefficient, the creep deformation of concrete under continuous load is calculated. Then, considering the relaxation effect of the prestressing tendons, the amount of prestress loss over time is calculated; Furthermore, based on the concrete protective layer thickness, water-cement ratio, and pitting coefficient, the annual corrosion depth increment of the prestressed tendons is calculated by integration. Meanwhile, based on the relative displacement data of adjacent piers caused by hydrodynamic action and the fatigue crack propagation coefficient, the fatigue crack depth increment of prestressed tendons under reciprocating displacement is calculated.

4. The method for deformation calculation and life assessment of prestressed beam bridges based on creep-corrosion-hydraulic fatigue coupling as described in claim 1, characterized in that, In S2, the specific process of determining the failure depth of the prestressing tendon based on the competition criterion of corrosion and fatigue cracking, and then calculating its failure area, includes: Compare the increase in corrosion depth of prestressed tendons with the increase in fatigue cracking depth within the same year, and take the larger of the two as the failure depth increase for that year. Then, the failure depth increment of this year is added to the cumulative failure depth of the previous year to obtain the total failure depth of the current year; Furthermore, based on the relative relationship between the failure depth and the prestressed tendon diameter, different geometric calculation methods are used to determine the failure area. When the failure depth does not exceed the critical value, the failure area is calculated by piecewise integration. When it exceeds the critical value, the loss is calculated based on the loss of the complete section.

5. The method for deformation calculation and life assessment of prestressed beam bridges based on creep-corrosion-hydraulic fatigue coupling as described in claim 1, characterized in that, In S2, the specific process of calculating the interfacial bond stress and interfacial spring stiffness, and updating the long-term performance influence parameters of concrete and prestressed tendons in the hydrodynamic simulation model of the beam bridge includes: Based on the stress state, failure depth, and anchorage length of the prestressing tendons, calculate the bond stress distribution between the concrete and the prestressing tendons. Then, based on the elastic modulus of the prestressed tendons and the cross-sectional area loss, the interface spring stiffness coefficient is calculated; Then, the calculated bond stress, spring stiffness, and updated material parameters are input into the hydrodynamic simulation model of the beam bridge.

6. The method for deformation calculation and life assessment of prestressed beam bridges based on creep-corrosion-hydraulic fatigue coupling as described in claim 1, characterized in that, In S3, based on the updated parameters from S2 and the hydrodynamic simulation model of the beam bridge, hydrodynamic and long-term effect loading simulation analysis is performed, and the mid-span deflection is extracted. f The longitudinal relative displacement between adjacent piers and the prestress amplitude were calculated, along with the corrosion-hydraulic coupled fatigue life of the prestressing tendons. T fatigue The specific process includes: Input the updated concrete creep parameters, prestressed tendon section parameters, and interface bond parameters from S2 into the hydrodynamic simulation model of the beam bridge; Then, the fluid domain incident velocity mode is set, and long-term effect loads such as the bridge's self-weight dead load are applied. Then, hydrodynamic-structural coupled simulation calculations were performed to extract the deflection value at the mid-span section. f、 Time history data of longitudinal relative displacement between adjacent bridge piers; Simultaneously, based on the relative displacement data, the stress amplitude of the prestressing tendons is calculated. Combined with the prestressing tendon failure depth data obtained from S2, the corrosion-hydraulic coupled fatigue life of the prestressing tendons is obtained through the fatigue life calculation formula. T fatigue .

7. The method for deformation calculation and life assessment of prestressed beam bridges based on creep-corrosion-hydraulic fatigue coupling as described in claim 1, characterized in that, In S4, it is determined whether the mid-span deflection has reached the critical deformation. f th Has the current service life reached the critical age limit? T th Or whether the prestressed tendon corrosion-hydraulic coupling fatigue life has been reached. T fatigue The service duration is determined based on the first of the three events, and the specific process includes: Compare current mid-span deflection f With preset critical deformation f th The size relationship is recorded, and the service life at which the critical deformation is reached is recorded. T 1 ; Then, compare the current service life t with the preset critical service life. T th The size relationship is recorded, and the service life that has reached the critical service life is recorded. T 2 ; Furthermore, the current service life t is compared with the corrosion-hydraulic coupled fatigue life of the prestressed tendons. T fatigue The size relationship is recorded, along with the service life at which fatigue life is reached. T 3 ; Finally, take T 1 、T 2 、T 3 The minimum value in the range is taken as the final service life of the structure.

8. The method for deformation calculation and life assessment of prestressed beam bridges based on creep-corrosion-hydraulic fatigue coupling as described in claim 1, characterized in that, In S5, the service year t is incremented to t+1, and steps S2 to S4 are repeated until the exit condition is met, and the deformation time curve is output. The specific process includes: Increase the current service year t by 1 year to use as the new calculation year; The parameter update process was repeated according to S2, including concrete creep calculation, prestressed tendon failure depth calculation, and interface parameter update. Then, based on the updated parameters, S3 simulation analysis is performed to obtain deformation and life data for the new year; Next, the judgment criteria of S4 are used to check whether any exit condition is met. The exit conditions include reaching critical deformation, reaching critical lifespan, and reaching fatigue life. If the exit condition is not met, continue executing S2 to S4 in a loop; If any exit condition is met, the calculation terminates and the output is a deformation-time curve containing the mid-span deflection values ​​for each year.

9. An electronic device, comprising a memory and a processor, characterized in that, The processor is used to execute the program in the memory to implement the deformation calculation and life assessment method for the creep-corrosion-hydraulic fatigue coupling of prestressed beam bridges as described in any one of claims 1 to 8.

10. A storage medium containing computer-executable instructions, characterized in that, When the computer-executable instructions are executed by a computer processor, the storage medium of the computer-executable instructions is used to perform the deformation calculation and life assessment method for the creep-corrosion-hydraulic fatigue coupling of prestressed beam bridges as described in any one of claims 1 to 8.

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