9 results about "Beam finite elements" patented technology

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 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 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.

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 invention belongs to the technical field of bridge engineering, and discloses a large-span cable-stayed bridge damping cable damping optimization method, which specifically comprises the following steps of: 1, establishing a bridge finite element model considering the temperature related characteristics of a damper, and according to a bridge design drawing, constructing a bridge finite element model; structural analysis software is adopted to construct a three-dimensional finite element model comprising a main beam, a bridge tower, an inclined damping cable, a support and a foundation. The mechanical parameters of the damper are defined as temperature related variables, the double-characteristic temperature is determined in combination with bridge site long-term meteorological data, and the influence of the temperature on the performance of the damper is accurately represented in cooperation with a viscosity-temperature characteristic curve with high fitting precision; through standardized dynamic response analysis and numerical optimization under the working condition of double extreme temperatures, the obtained optimal parameters can meet the requirements of extreme environments in summer and winter at the same time, and the problem of seasonal performance failure caused by traditional fixed parameter design is thoroughly solved; and then all-weather stable work of the damper is ensured through full-temperature-range multi-node verification.

The application discloses a train loading method and device for calculating train bridge dynamic response, and relates to the technical field of bridge dynamic analysis. The method comprises the following steps: based on an established bridge finite element analysis model, setting a train load loading node interval, and forming a dynamic loading node sequence; a virtual beam unit is established between the dynamic loading node sequence, and the length of the virtual beam unit before and after each dynamic loading node is calculated; the time when the train head reaches each dynamic loading node is calculated; the equivalent node force of the train uniform load and the concentrated force is calculated, and the equivalent node force of the dynamic loading node is obtained; the equivalent node concentrated force loading time function is obtained; the input file of the finite element software is generated according to the equivalent node concentrated force loading time function corresponding to each dynamic loading node and the train head arrival time, and is led to the finite element software, so that the train dynamic load moving loading is realized. The application reduces the node loading data, and greatly shortens the calculation time.

A method, device, and equipment for monitoring the bridge condition during bridge construction are provided. The monitoring method includes: acquiring sensor monitoring datasets at different characteristic locations of the bridge during the current construction stage; preprocessing the sensor monitoring datasets to obtain a preprocessed dataset; extracting key feature data from the preprocessed dataset to obtain a feature dataset for the current construction stage; performing data fusion processing on the feature datasets to obtain a feature fusion dataset; inputting the fused strain data, stress data, strength data, and geometric alignment data from the feature fusion dataset into a pre-established overall bridge finite element model to obtain a first alignment dataset, wherein the first alignment dataset represents the set of alignment data at each location of the bridge during the current construction stage; obtaining an alignment matching degree set based on the first alignment dataset and a preset first alignment dataset; and determining a preset second alignment dataset for the next construction stage based on the alignment matching degree set.