48 results about "Beam finite elements" patented technology

The invention provides a bridge pier nonlinear earthquake random response analysis method based on a BWBN model, and belongs to the field of civil engineering structure random vibration analys.The method comprises the steps that discretization processing is conducted on a concrete bridge pier structure, and a finite element nonlinear analysis numerical model is constructed; constructing a BWBN model by combining linear and nonlinear differential equations, setting a hysteresis parameter value of the BWBN model, simulating by adopting an Euler-Bernoulli beam unit, and establishing a degraded beam finite element model; obtaining a unit hysteresis vector, constructing a system motion balance equation, solving an equivalent linearization coefficient, constructing a covariance matrix of random response of the concrete pier structure, performing random response analysis on the concrete pier structure, and exploring typical working conditions of random excitation. According to the method, the operation time is shortened, the calculation precision is improved, and meanwhile, the response characteristics of the reinforced concrete pier structure under nonlinear earthquake random excitation can be truly represented.

The invention relates to the technical field of bridge bearing capacity evaluation, in particular to a bridge bearing capacity accurate evaluation method, which comprises the following steps: acquiring stress data and deflection data of each position of a bridge under different static loads, and acquiring vibration data of each position of the bridge under the application of a dynamic load; according to the data distribution change and fluctuation degree of each position of the bridge under different static loads, a bridge stress change abnormal value and a bridge deflection data change abnormal value are obtained in combination with nonlinear change characteristics of the data, so that an abnormal coefficient of bridge stress deformation is obtained; the method comprises the following steps: acquiring significant values of abnormal vibration of each position under a dynamic load, further obtaining a comprehensive deviation coefficient of each position under the action of multiple loads, calculating a vulnerability degree value of each position of a bridge, adjusting a grid size in a bridge finite element model construction process, and counting bearing capacity of the bridge under different loads based on the bridge finite element model. The accuracy of the evaluation result of the bridge bearing capacity can be improved.

The invention discloses a bridge construction global monitoring method and system based on finite element real-time calculation, and the method comprises the steps: constructing a bridge finite element model, carrying out the division of finite element units, carrying out the unique coding of each unit, and dividing the construction stages; a three-dimensional space geometric corresponding relation between the finite element model and the BIM model is constructed, and mapping of finite element units and BIM model components is carried out; determining an allowable stress through a construction material of a bridge member, and further setting an early warning threshold value of each unit of the finite element; load variables needing to be considered in the construction process are determined; configuring a finite element calculation server to perform real-time calculation; obtaining a finite element calculation result, modifying the stress of each component of the three-dimensional BIM model according to the result, and globally displaying the result; and a three-level early warning mechanism is set for monitoring and early warning. The invention provides a comprehensive supervision method for knowing the global stress state of the bridge and guaranteeing the safety of the bridge.

The invention provides a large-span suspension bridge buffeting analysis method and system based on digital twinning, and relates to the technical field of road and bridge safety, and the method comprises the steps: obtaining a bridge finite element model of a target large-span suspension bridge in a design stage, the fluctuating wind speed time history data, the acceleration data, the actually measured displacement response data and the actually measured acceleration response data are acquired on site; performing parameter optimization on the bridge finite element model according to the acceleration data to obtain structural parameters; performing parameter extraction according to the fluctuating wind speed time history data to obtain wind parameters; performing finite element analysis according to the actually measured displacement response data, the actually measured acceleration response data and the wind parameters to obtain aerodynamic parameters; power load parameters acting on the bridge are obtained through calculation according to the wind parameters and the aerodynamic parameters; and constructing the digital twin according to the dynamic load parameters and the structural parameters. According to the method, high-precision simulation and prediction of the buffeting response of the large-span suspension bridge in a real service environment are realized.

The invention provides a correction method of a bridge finite element model, and relates to the field of bridge engineering. According to the method, bridge design drawings, construction records and actual detection data are collected, an initial finite element model is established, key parameters are initialized, a trained neural network model is utilized to evaluate initial grid quality, a self-adaptive grid division technology and engineering experience are combined to optimize grids, parameter sensitivity analysis is carried out through a machine learning algorithm, and the quality of the grid is evaluated. Key correction objects are screened, an optimal parameter combination is automatically searched by using a deep learning model or an optimization algorithm, and finally, the corrected model is comprehensively verified by adopting an independent verification data set. The method improves the model correction efficiency and precision, enhances the adaptability to a complex bridge, and provides a reliable basis for bridge safety assessment and maintenance.

The invention discloses a damage assessment method for a shallow-buried foundation bridge under a flood disaster. The method comprises the following steps: constructing a finite element model of the shallow-buried foundation bridge; introducing uncertainty of flood level height, foundation scouring pit length and scouring depth by applying a random Pushover method, obtaining bridge pier top yield displacement of the shallow foundation bridge under multiple groups of scouring working conditions, and calculating first two moments of logarithm of the flood-fighting capacity of the structure to obtain the flood-fighting capacity; performing flood-fighting demand analysis on the response of the shallow-buried foundation bridge in different flood washing environments based on a finite element reliability method; the flood-fighting capacity is compared with demand analysis, the failure probability of the shallow-buried foundation bridge under different working conditions is evaluated, fitting is conducted through the least square method, and a vulnerability curve of the shallow-buried foundation bridge is generated. According to the damage assessment method for the shallow-buried foundation bridge under the flood disaster, the influence of multiple factors such as the flow velocity and the scouring depth on the performance of the shallow-buried foundation bridge can be quantified, and the damage state of each stage of the shallow-buried foundation bridge is effectively assessed.

The application discloses an Abaqus parameterized modeling and analysis method for a corrugated steel web combined channel girder based on Excel, and comprises the following steps: (1) a user determines the TGCW size, material and finite element analysis type required by the user according to project data; (2) a program running environment is configured, a third-party library function xlrd2 is installed, and the parameter information obtained in the step (1) is filled into an Excel input table of the corrugated steel web combined channel girder finite element analysis parameters; (3) TGCW parameter information in an Excel file is read through a Python script file; (4) TGCW related model information is defined through the Python script; (5) the Python script is run on an Abaqus platform, a TGCW finite element model is generated, and simulation analysis corresponding to the input parameters is carried out. The application can complete the modeling work of a complex model without relying on third-party modeling software, can realize an automatic modeling process, and is convenient for realizing parameterized analysis on the corrugated steel web combined channel girder.

The invention discloses a bridge model correction method of a frequency and deflection influence line dual-objective function, and belongs to the technical field of bridge finite element model correction. According to the method, the VMD is combined with the Tikhonov regularization influence line identification method, vehicle-induced bridge response power components and multi-axis effect interference are effectively eliminated, the actually-measured deflection time history response of the bridge is restored to the deflection influence line under the unit concentrated load, the effect of identifying the variable-cross-section steel-concrete combined continuous beam bridge influence line is good, and the applicability is wide; according to the model correction method based on combination of a PSO-BP agent model and NSGA-II dual-objective optimization, a complex implicit function relationship between a to-be-corrected parameter and an objective function can be effectively constructed, a Pareto coordinated optimal solution under the dual-objective optimization problem is obtained, then a corrected parameter is obtained, and finite element model correction is achieved.

The invention discloses a bridge finite element real-time analysis method and system, and the method comprises the steps: constructing a finite element model of a structure, and dividing the finite element model into a plurality of finite element units through discretization processing; calculating an overall stiffness matrix K according to the established finite element model; in combination with the boundary condition of the structure, recalculating to obtain a processed total stiffness matrix K ', and carrying out serialization operation on the processed total stiffness matrix K '; selecting a position for storing the sparse matrix according to a specific computing environment; according to the load information acquired by the sensor, converting the load information into a corresponding load vector in the finite element model; and combining the cached total stiffness matrix K'with a load vector, solving node displacement and structural response, and transmitting a result to a post-processing module. According to the method, the required data are efficiently accessed according to different calculation requirements on the basis of a sparse matrix cache strategy, when the load changes, only the load vector needs to be recalculated and solved, the overall stiffness matrix does not need to be recalculated, and the calculation efficiency is improved.

The invention relates to an optimization method for a cast-in-place section support of a hybrid beam cable-stayed bridge. The optimization method comprises the following steps that S1, environment parameters needed by modeling, attribute parameters of a bridge and spatial position limiting parameters of the support are determined; s2, determining the overall arrangement of the support; s3, determining arrangement of a box girder inner mold and an inner mold support; s4, determining the arrangement of a box girder outer mold and longitudinal and transverse distribution girders; s5, constructing a single-beam finite element model to carry out bracket overall calculation; s6, determining a preliminary scheme of the support, and establishing a three-dimensional finite element model for mechanical calculation of the support; s7, establishing a support-girder finite element model for cooperative calculation; s8, carrying out support pile foundation design and settlement calculation; s9, the pre-lifting amount of the cast-in-place section support is calculated; and S10, carrying out cast-in-place section support structure design. Safety and stability of the support in the whole construction period of the cable-stayed bridge can be guaranteed.

This invention relates to a multi-mode vortex-induced vibration control method for long-span bridges based on multiple SATMDI (Self-Active Capacitive Tuned Mass Damper) dampers, belonging to the field of structural vibration control. The invention addresses the problem of insufficient optimization in existing semi-active controlled SATMDI settings. The method comprises the following steps: Step 1: Establishing a finite element model of the bridge and extracting modal information for each order; Step 2: Screening the bridge modes, retaining modes with natural frequencies lower than the highest vortex shedding frequency; Step 3: Determining the vortex-induced vibration amplitude limits [A] for each mode requiring control. n ], and then obtain the allowable value of the peak value of the dynamic amplification coefficient of each mode of the bridge; Step 4, divide the retained modes into G groups, and obtain the sum of the minimum additional mass required for each group of modes; Repeat step 4 P times, regrouping each time, and obtain P results; Step 5, take the grouping strategy with the minimum value among the P results as the optimal grouping strategy, and obtain the minimum additional mass required to control all modes and the corresponding optimal SATMDI deployment position.

The application discloses a kind of bridge crane stress history acquisition method and system, the method includes obtaining the characteristic data of crane actual working state under preset time;The hoisting load data of preset time is expanded by Latin hypercube sampling technique, obtain the hoisting load data of crane inspection cycle, the hoisting load data of inspection cycle is input into the pre-trained tentacle-least squares support vector machine prediction model, and the predicted working cycle number is obtained;The hoisting load data of inspection cycle and the predicted working cycle number are converted into the trolley wheel pressure of equal sample size;The finite element model of crane girder is established, and the trolley is simulated with random load at rated speed from the side span of girder to the other side span, after traversing all trolley wheel pressure load, the stress history of crane girder at any position in inspection cycle is obtained.The application provides high-precision stress characteristic data for crane structure fatigue life assessment.

The present invention discloses a vibration response assessment method and system for a wind-vehicle-bridge system with weak lateral stiffness. The method considers the coupling effect of wind loads in a spatiotemporally varying wind field on the vehicle and the weak lateral stiffness track beam, the influence of wind loads on the wheel-rail relationship, and the initial inclination and various forces of the track beam caused by factors such as track beam installation errors and prestressing. A dual-model system of a vehicle subsystem dynamic equation and a track beam finite element model is established. By interacting with the dual models, a dynamic response result after convergence of the vibration analysis is obtained, providing theoretical support for the wind-vehicle-bridge coupling analysis of the weak lateral stiffness track beam, thereby effectively assessing the vibration response of the wind-vehicle-bridge system of a straddle-type monorail, so that the vibration analysis results are consistent with the actual operating conditions, and facilitating designers to take vibration reduction measures in advance to reduce safety risks and improve operational comfort.

The present application relates to the technical field of bridge health monitoring and detection, and discloses a prefabricated assembled beam bridge longitudinal damage rapid diagnosis method, which comprises the following steps: collecting actual structure parameters of a bridge, establishing a bridge finite element calculation model for calculating a theoretical strain influence line; arranging strain measuring points at the longitudinal midspan of the two outer side beams and the middle beam of the prefabricated assembled beam, and performing a pseudo-static loading test; extracting the strain of the beam bridge strain measuring points, fitting and drawing a strain influence line; calculating the total strain meters of the two outer side beam strain measuring points; calculating the total strain meter change amplitude ΔS of the two outer side beam measuring points; establishing a ΔS column chart of the two in the same coordinate axis, and comparing with a longitudinal damage qualitative diagnosis graph system to obtain a qualitative diagnosis result. The prefabricated assembled beam bridge longitudinal damage rapid diagnosis method has the advantages of short diagnosis time, no interruption of traffic, improved economy, realization of rapid comprehensive diagnosis of the prefabricated assembled beam bridge longitudinal damage, and improved diagnosis accuracy.

The invention relates to a twin thin-walled beam optimization method and device for a vehicle and electronic equipment, and the method comprises the steps: building a twin thin-walled beam multi-angle crashworthiness data set based on a pre-built twin thin-walled beam finite element model; based on geometric parameters and material parameters of the twin thin-walled beam, constructing a reduction design domain meeting multiple targets; a specific energy absorption polynomial agent model and a peak force polynomial agent model are constructed on the basis of a twin thin-walled beam multi-angle crashworthiness data set, and the specific energy absorption polynomial agent model and the peak force polynomial agent model are constructed on the basis of a reduced design domain. And a preset multi-target genetic algorithm-second generation non-dominant sorting genetic algorithm NSGA-II is utilized to perform optimization to obtain optimal parameters of the twin thin-walled beam, so that the twin thin-walled beam is optimized. Therefore, the problem that a plurality of optimization targets conflict in the design process of the thin-walled beam structure in related technologies is solved, the multi-angle crashworthiness design of the twin thin-walled beam for the vehicle is realized, and the efficiency of multi-target optimization design is effectively improved.

The present invention relates to the technical field of hull structure design, and particularly relates to a method for optimizing the stiffness of blocking timbers based on the strength of the hull during docking. The method for optimizing the stiffness of blocking timbers based on the strength of the hull during docking proposed by the present invention, based on the one-dimensional beam finite element model of the hull during docking, can efficiently obtain a relatively reasonable distribution of the stiffness coefficients of the blocking timbers within a limited time through technical means such as experimental design, approximate models, and optimization algorithms, greatly shortening the time for designing the stiffness coefficients of the blocking timbers, and helping to improve the reaction force level of the target blocking timbers, ensuring the safety of the hull structure during docking, and effectively improving the efficiency of formulating the ship docking plan.

The present invention discloses a method and device for equivalent calculation of emergency stopping of trains on bridges, relating to the technical field of bridge analysis. The method includes: establishing a finite element analysis model of the bridge based on the bridge design drawings and analyzing to obtain the most unfavorable loading area of the bridge; determining the loading length of the train dynamic load according to the bridge information, the train load pattern and the length of the most unfavorable loading area of the bridge; calculating the time for the train to stop at the most unfavorable loading area of the bridge according to the train braking deceleration and the determined loading length of the train dynamic load; determining the node dynamic loading function based on the equivalent node load of the train and the time for the train to stop at the most unfavorable loading area of the bridge; and assigning the node dynamic loading function to all loading nodes to achieve equivalent dynamic loading of emergency stopping of the train. The present invention can reduce the time cost for engineering personnel to establish a finite element analysis model.

The present disclosure relates to a bridge sensor optimization layout and response reconstruction method, system and medium, relating to the field of bridges. The method comprises: establishing a finite element model of the bridge; deleting measurement points in the initial sensor layout scheme; calculating load transverse influence lines using the bridge finite element model, reconstructing strain response data of the deleted transverse strain measurement points; reconstructing displacement data of the deleted displacement measurement points and / or acceleration data of the acceleration measurement points based on the relationship between displacement and acceleration; reconstructing strain response data of the deleted longitudinal strain measurement points based on the relationship between strain and displacement, using sensor data of the retained longitudinal strain measurement points and using data of the longitudinal displacement measurement points; constructing the architecture of the BiLSTM neural network model; all sensor data and all reconstructed data are input into the network model, and the network model is used to predict the data of the deleted measurement points. The present disclosure realizes the optimization of the sensor layout while improving the reconstruction accuracy.

This invention discloses a method and system for calculating the time-varying reliability of cable corrosion fatigue in cable-stayed bridges. The method includes establishing and validating a finite element model of the cable-stayed bridge; simulating the time history of fluctuating wind speeds in the main girder and main tower using the harmonic synthesis method; obtaining the cable stress time history through buffeting analysis; establishing a probability model of equivalent stress amplitude and cycle number using the rainflow counting method and Miner's theory; constructing a probability model of the depth of dangerous pits and corrosion depth of steel wires under different corrosion degrees based on measured data; establishing a multi-stage series formula coupling pit evolution, pit-crack transformation, and crack propagation; constructing a limit state equation with a 2% wire breakage rate as a threshold; calculating the time-varying reliability of the cable under different wind speeds and corrosion degrees using random sampling; and statistically analyzing the mean and standard deviation of corrosion fatigue life. This invention accurately reflects the wind-corrosion coupling and multi-stage failure mechanism, is computationally reliable, and has strong versatility, making it suitable for safety assessment and life prediction of cables in various types of cable-stayed bridges.

The present invention discloses a method and system for intelligent hierarchical early warning of bridges with multiple sources and multiple scales. The method includes: establishing a finite element model of the bridge and a mid-span model with the largest deflection of the bridge; based on the constructed models, analyzing the influence of various different influencing factors on the deflection of the bridge, obtaining the internal forces borne by the bridge under different deflection degrees, and then analyzing the corresponding bridge crack conditions, and at the same time determining the deflection threshold of the mid-span of the bridge; based on the bridge crack conditions, dividing the deflection threshold of the mid-span of the bridge to obtain risk assessment levels; constructing the corresponding relationships between various different influencing factors and the changes in deflection and cracks, and determining the actual deflection and crack conditions of the bridge according to the actual values of various different influencing factors, and then determining the corresponding risk assessment levels. The present invention realizes the hierarchical early warning of the deflection and cracks of continuous rigid frame bridges, and selects corresponding countermeasures according to the levels of the deflection and cracks of continuous rigid frame bridges, ensuring the safety and durability of the bridge structure during the service period.

The present invention discloses a method for rapidly calculating the global strain field of a bridge, which relates to the field of bridge structure health monitoring. The method comprises: firstly, generating stress simulation data of sampling positions of the entire bridge based on finite element simulation; then, performing supervised training on a calculation model based on the stress simulation data of sampling positions of the entire bridge; finally, using the real-time measurement data of the bridge stress sensor as input, and performing rapid calculation of the stress of the entire bridge using the trained calculation model. The present invention realizes the establishment of a calculation workflow for a finite element model of a bridge under the action of random bridge deck loads with full automatic processing throughout the entire process.

The invention provides a bridge structure sunlight shadow recognition method, a bridge structure sunlight temperature effect calculation method and device and a storage medium, and the method comprises the steps: building a target bridge finite element model, and carrying out the mesh generation of the target bridge finite element model; copying the target bridge finite element model after mesh division to obtain a first copy model and a second copy model; keeping the grid precision of a first to-be-identified structure in the first copy model, simplifying all grids of a second to-be-identified structure in the first copy model into a whole unit, and performing sunlight shadow judgment on the first to-be-identified structure; keeping the grid precision of a second to-be-identified structure in the second copy model, simplifying all grids of a first to-be-identified structure in the second copy model into a whole unit, and performing sunlight shadow judgment on the second to-be-identified structure; and determining a sunlight unit and a shadow unit. By adopting the identification method provided by the invention, the sunlight shadow of the structure can be identified more accurately and quickly.

The invention relates to a bridge finite element model correction method based on a ground-based radar, and belongs to the technical field of structure monitoring. The method comprises the following steps: synchronously acquiring deformation data of a bridge by using a ground-based radar; carrying out noise reduction processing on the dynamic deflection by utilizing the combination of a variation mode decomposition algorithm optimized by the improved whale optimization algorithm and a wavelet threshold value; performing modal identification by using a frequency domain decomposition method, and determining main modals of the first four orders of the bridge structure; establishing a bridge initial finite element model, and realizing mapping through a Kriging agent model, namely establishing a correlation between a correction parameter and a target response value; according to the method, fitness functions are respectively constructed by adopting residual values of four-order modal vertical bending frequencies, finally, a Pareto set is obtained through calculation by improving a multi-target whale algorithm, meanwhile, indexes are proposed to measure the quality of solutions in the Pareto set, and an optimal solution is selected to be used for correcting the model. Compared with a traditional bridge finite element model correction mode, the method has the obvious advantages of being non-contact, high in speed, high in precision and the like.

The present invention provides a method and device for identifying the aerodynamic admittance of a long-span bridge based on operational measured data, relating to the field of bridge safety technology. The method comprises establishing a generalized equation of motion for a long-span bridge under buffeting forces; establishing a bridge finite element model, updating the bridge finite element model using operational measured data to obtain an optimal bridge finite element model; calculating the fluctuating wind coherence function of the long-span bridge main beam; obtaining the three-force coefficient, three-force, and generalized buffeting force of the long-span bridge under different wind attack angles based on the optimal bridge finite element model; performing frequency domain analysis on the generalized equation of motion to obtain a simulated power spectrum density at each point on the long-span bridge main beam; and identifying aerodynamic admittance parameters in a preset aerodynamic admittance function based on the simulated power spectrum density to complete the aerodynamic admittance identification of the long-span bridge. The present invention solves the problem that existing methods are unable to identify the aerodynamic admittance of a long-span bridge during operation.

The present disclosure provides a method and system for visual rendering of the structural mechanical properties of a digital twin bridge, relating to the technical field of visualizing the structural mechanical properties of a bridge, including: obtaining the load distribution state of vehicles on the bridge deck; based on the load distribution state, combining with the finite element model of the bridge to determine the deflection-time curve and the cable force-time curve of the deflection change control points of the bridge main girder; converting the deflection-time curve and the cable force-time curve into the HSV color model by a coloring algorithm based on the Sigmoid function, and converting the HSV color model into the RGB color model; using the UE4 engine to perform visual rendering on the digital twin bridge based on the RGB color model. This method improves the accuracy of bridge health monitoring, and through visualization means, the structural state and potential problems of the bridge are more easily identified and understood. The present disclosure also provides a system for visual rendering of the structural mechanical properties of a digital twin bridge, an electronic device, and a storage medium.

The invention discloses a monitoring data and natural language driven bridge finite element model rapid construction method, system and device and a storage medium, and belongs to the technical field of bridge models.The method comprises the following steps that a bridge initial finite element model is constructed based on Midas Civil NX and a natural language; optimized and corrected bridge finite element model parameters are obtained based on the bridge initial finite element model and the PSO optimization model architecture, the bridge initial finite element model is corrected, and a bridge reference finite element model capable of reflecting the real state of the structure is obtained; and importing the obtained bridge key monitoring data into the bridge reference finite element model in real time, calculating an accurate bridge structure response and verification coefficient, and carrying out rapid verification and visual display on the safety state of the bridge structure. According to the method, efficient construction of the bridge finite element model is achieved, the method is particularly suitable for large-quantity and wide-range bridge groups with similar structural forms, and technical support is provided for scheme design and safety inspection of a bridge monitoring system.

The application discloses a bridge finite element real-time analysis method and system, which comprises the following steps: constructing a finite element model of a structure, dividing the model into a plurality of finite element units through discretization processing; calculating a total stiffness matrix K according to the established finite element model; re-calculating a processed total stiffness matrix K' in combination with the boundary conditions of the structure, and performing a serialization operation on the processed total stiffness matrix K'; selecting a position for storing a sparse matrix according to a specific calculation environment; converting load information obtained by a sensor into a corresponding load vector in the finite element model according to the load information; combining the cached total stiffness matrix K' and the load vector, solving node displacement and structure response, and delivering the results to a post-processing module. The application is based on the strategy of sparse matrix caching, efficiently accesses required data according to different calculation requirements, and only needs to re-calculate the load vector and solve when the load changes, without the need to re-calculate the total stiffness matrix, thereby improving the calculation efficiency.

The present application relates to a kind of bridge structure load test method and system for evaluating bearing capacity, belong to bridge safety detection and evaluation technical field, solve the problem that current load test needs to close traffic or slow driving to cause high cost and difficult to realize.The present application includes determining each test measuring point of the bridge to be evaluated, collecting the dynamic strain measured data or dynamic deflection measured data of large transport vehicle at each test measuring point at each time;After filtering noise, corresponding dynamic strain baseline data or dynamic deflection baseline data is obtained;According to dynamic strain measured data or dynamic deflection measured data, and corresponding dynamic strain baseline data or dynamic deflection baseline data, the quasi-static strain or deflection measured value of each test measuring point is obtained;Based on the finite element mechanics model of the bridge to be evaluated, the strain or deflection calculation value of each test measuring point is calculated, and according to the quasi-static strain or deflection measured value of each test measuring point, the calibration coefficient of each test measuring point is calculated to evaluate bearing capacity.The present application realizes the real-time evaluation of bridge bearing capacity.

This invention discloses a physical-data fusion-based method for rapid stress spectrum modeling and fatigue life prediction of bridge cranes, belonging to the field of crane structure safety assessment technology. Addressing the problems of low efficiency in traditional finite element stress calculation, the lack of consideration for the influence of variable stress ratios in conventional crack propagation models, and unreasonable handling of multiple alternating loads in a single working cycle, this invention establishes a stress sample library by building a finite element model of the crane's main beam and uses a gradient boosting decision tree model to achieve rapid stress prediction at critical points. Based on measured load spectra, the maximum and minimum stress values ​​of a single cycle are extracted to generate a stress spectrum. The Walker formula is used to correct the crack propagation rate, and the life prediction is completed by combining a periodic sample cycle method. This invention improves the efficiency of stress spectrum acquisition, ensuring that the stress spectrum compilation closely reflects actual service conditions, while correcting the life prediction deviation caused by variable stress ratios. It can be used for fatigue safety assessment and life prediction of in-service bridge crane metal structures, demonstrating high engineering practicality.

The application discloses a kind of bridge construction global monitoring method and system based on finite element real-time calculation, method includes: constructing bridge finite element model, carries out finite element unit division, for each unit is uniquely coded and divides construction stage;The three-dimensional space geometric correspondence of constructing finite element model and BIM model is established, and the mapping of finite element unit and BIM model component is carried out;The allowable stress is determined by the construction material of bridge component, to further set the early warning threshold of each unit of finite element;Determine the load variable that needs to be considered in construction process;Configure finite element calculation server, carry out real-time calculation;Obtain finite element calculation result, modify the stress of each component of three-dimensional BIM model according to result, globally show result;Set up three-level early warning mechanism, carry out monitoring and early warning.A kind of stress state of knowing bridge global is provided, guarantee the bridge safety comprehensive supervision method.