143 results about "Bridging model" patented technology

A mechanism for segregating traffic amongst STAs that are associated with a bridge, referred to herein as the personal virtual bridged local area network (personal VLAN), is based upon the use of a VLAN to segregate traffic. The IEEE 802.1Q-1998 (virtual bridged LANs) protocol provides a mechanism that is extended by the invention to partition a LAN segment logically into multiple VLANs. In the preferred embodiment, a VLAN bridge forwards unicast and group frames only to those ports that serve the VLAN to which the frames belong. One embodiment of the invention extends the standard VLAN bridge model to provide a mechanism that is suitable for use within an AP. In a preferred embodiment, the Personal VLAN bridge extends the standard VLAN bridge in at least any of the following ways: VLAN discovery in which a personal VLAN bridge provides a protocol for VLAN discovery; VLAN extension in which a Personal VLAN allows a station to create a new port that serves a new VLAN, or to join an existing VLAN via an authentication protocol; Logical ports in which a Personal VLAN bridge can maintain more than one logical port per physical port, and bridges between ports of any kind; and cryptographic VLAN separation.

The present invention discloses a bridge three-dimensional model construction method based on the BIM. The method comprises the following steps: dividing objects of an whole structure of the bridge, and classifying the objects of the bridge in a normative manner; subdividing the bridge components into elements and primitives, parameterizing the elements and primitives, and formulating a parameter table corresponding to the geometric dimensions; carrying out assembly and positioning on the three-dimensional model of the bridge components, determining and defining element control points and relative spatial position relationships, assembling the elements into components, storing the components into an component template library, and establishing component control points; extracting three-dimensional route information of the project, and determining stake marks and the design elevation of the route; and assembling the component three-dimensional model, based on the route information, using positioning parameters to determine the location of the component model, and calling the type method, so that parametric assembly can be automatically carried out between components. According to the method disclosed by the present invention, by optimizing the bridge model, parameterization and standardization of the bridge components are realized, the modeling time is shortened, and the design efficiency and quality are improved.

The invention discloses a random recognition method for bridge floor moving vehicle loads. The method comprises the following steps that (1) raster sensors, strain sensors and acceleration sensors are arranged on a bridge floor to obtain running speeds of moving vehicles and the dynamic strain and acceleration responses of a bridge under the action of the moving vehicle loads; (2) an accurate structural finite element model is established for a bridge structure, model condensation is carried out, and the freedom degree of the bridge model after the model condensation is made to be matched with dynamic strain signal measuring positions; (3) the deterministic components of bridge random dynamic displacement, speed and acceleration are obtained by utilizing a KL decomposition technique on the basis of actual measurement dynamic strain response samples; (4) the deterministic components random moving vehicle loads on the bridge floor are recognized by directly adopting a sample matrix inversion and a Tikhonov regularization method; (5) the statistical properties, average time history and variance, of the random moving vehicle loads are obtained.

The invention relates to a cable laying method and system. The cable laying method comprises the following steps of: acquiring three-dimensional (3D) bridge information built by 3D design software; matching a bridge number in the 3D bridge information with a bridge type in a database to find the bridge type corresponding to the bridge number and realize the conversion of the bridge number to the bridge type; and forming a 3D bridge mode according to imported bridge position information, device position information and the bridge type in the 3D bridge information. By the cable laying method, the bridge position information, the device position information and the bridge type are unnecessarily reset in the cable laying system to build the 3D bridge model; through information matching, the bridge number in the 3D bridge information built by the 3D design software is converted into information required for cable laying, namely the bridge type, the bridge type is unnecessarily set, and thus the laying efficiency is improved; and the most reasonable cable path is searched according to parameters related to cable laying, rapidness and accuracy are achieved, manual labor is not needed to search the path, and the laying efficiency is improved.

The invention discloses a bridge damage identification method based on a neural network. The method includes the following steps of firstly, constructing sample data, wherein a bridge model is established with a finite element method, simulation strain data are obtained under the condition that a bridge is complete and under the condition that the bridge is differently damaged, and the strain change rates serve as the sample data of the BP neural network; secondly, determining a network topology structure, wherein the number of hidden layers of the BP neural network and the number of nerve cells contained on each layer are determined, and meanwhile the weight threshold value of the neural network is initialized; thirdly, conducting training and testing, wherein the BP neural network is trained through a gradient descent momentum algorithm, and the neural network is tested through a testing sample; fourthly, identifying the damage, wherein the damage of the bridge is identified by inputting the real-time train data of the bridge into the trained BP neural network. The bridge is identified through stress parameters, and therefore bridge damage identification accuracy is improved.

The invention discloses a dynamic simulation test system for ensuring running safety of a train on a railway bridge under an earthquake. The dynamic simulation test system comprises a bridge model and a train model, wherein a supporting frame component for supporting the bridge model and adjusting an inclination angle and a horizontal position of the bridge model is arranged at the bottom of the bridge model; track boards are paved on the bridge surface of the bridge model; train tracks for guiding a running route of the train model and central tracks for preventing the train model from falling off are paved on the track boards; the train tracks are parallel to the central tracks; the bridge model comprises a first supporting section for adjusting a preset speed of the train model through the inclination angle, a test section for performing a train-bridge coupling vibration test and a second supporting section for stopping the running of the train model according to the inclination angle; the first supporting section and the second supporting section are respectively connected to two ends of the test section. The weak action of the bridge, which is caused by the upper train, and strong action of bridge vibration, which is caused by a vibration table, are mutually coupled to realize a train and earthquake mixing simulation system.

The invention relates to a single tower cable-stayed bridge model test system based on damage identification for the field of bridge test science. The test system comprises a single tower cable-stayed bridge model, a lever loading system and a cable tension test system, wherein the single tower cable-stayed bridge model comprises a main bridge, a main tower, a stayed cable, a support, a base and a support upright which are assembled together; the lever loading system comprises a gantry device, a lever device and a lintel device, wherein the gantry is transversely arranged above the main beam of the single tower cable-stayed bridge model, and the lintel device is placed on the main beam of the single tower cable-stayed bridge model; and the cable tension test system comprises an anchoring screw, a leveling block, a pressure ring sensor and an adjusting nut which are mounted in a cable beam anchoring area. According to the invention, model tests for the dynamic and static performance ofthe cable-stayed bridge and experimental studies on the damage identification method of the cable-stayed bridge structure can be performed; and moreover, real-time and quick measurement of the cable tension can be realized without changing the cable rigidity, and thus the problem of difficult measurement of cable tension in the cable-stayed bridge model is solved.

The invention discloses a method for assessing the detail fatigue crack propagation of a steel bridge. Aiming at a steel bridge which is widely used in a road bridge system and is severe in fatigue crack dangers, the method comprises the steps: firstly building a bridge model and a local zone crack submodel through finite elements, obtaining an existing bridge load according to the definition and sampling of a vehicle and other random variables, and obtaining the boundary conditions of the submodel based on the whole bridge finite element analysis and the submodel technology; secondly updating the submodel through employing local remeshing, and carrying out the crack propagation finite element analysis; thirdly extracting a stress intensity factor amplitude, calculating a mean crack propagation rate, a mean crack propagation angle, the circulating number of times of each crack propagation step, the mean number of the stress intensity factor amplitude caused by a single vehicle, and the fatigue life; finally achieving the simulation of the fatigue crack of the steel bridge and the assessment of the fatigue life, so as to guide the subsequent maintenance and reinforcing operation.

The invention discloses a method for optimized arrangement of a strain sensor. The method comprises the following steps of building a simplified bridge model, confirming a monitoring cross section needing to be provided with the strain sensor, building a structural multi-scale finite element model on a bridge section including the monitoring cross section, obtaining the position which is located on the monitoring cross section, is stressed adversely and needs to be provided with the strain sensor, building a mesoscopic model of a local detail of a critical element on the monitoring cross section, carrying out hot spot stress analysis, and confirming the spot distribution position of the local detail. By the help of a multi-scale finite element modeling strategy, the method provides an optimized scheme of the strain sensor in a health monitoring system of a bridge, especially a long-span bridge by different levels, can obtain the comprehensive information of structural critical positions with few strain sensors, and is both safe and economical.

The invention comprises three extensions of the IEEE 802.1Q VLAN bridge model. The first extension is the cryptographic separation of VLANs over trunk links. A LAN segment type referred to as an encapsulated LAN segment is introduced. All frames on such a segment are encapsulated according to an encryption and authentication code scheme. The second extension is the division of a trunk port into inbound and outbound ports. The third extension is a protocol that automatically infers for each outbound port in a bridged VLAN, a set of LAN segment types for the port that minimizes the number of transfers between encapsulated and unencapsulated segments required to transport a frame in the bridged VLAN.

The invention discloses a bridge pier crack nondestructive quantitative detection method based on unmanned aerial vehicle remote sensing. The images of the bridge body and each bridge pier and the corresponding photographing center coordinate information are acquired; a three-dimensional true color bridge model is generated; a crack two-dimensional image object is acquired; a crack three-dimensional spatial object is acquired; and a crack plane projection object is acquired and the crack attribute information is calculated. The advantages of small size and flexibility of the unmanned aerial vehicle can be fully utilized to realize rapid and efficient detection of the crack of the high bridge pier, the high tower and other areas where people have difficulty to reach, the quantitative information can be nondestructively acquired, and the data support can be provided for scientific and refined bridge detection and maintenance in time.

The invention discloses a method for 3D parameterization modeling of a high-speed railroad bridge under a virtual reality environment, wherein a 3D module of a bridge can be quickly and accurately established based on the characteristics of bridge assemblies and the interaction principle between the assemblies, and a convenient model editing and modifying method is provided, so as to provide a powerful technical support for improving the design level of the high-speed railroad bridge. The technical steps of the 3D parameterization modeling of the high-speed railroad bridge under the virtual reality environment includes S1-beam 3D parameterization modeling, S2-railroad track 3D parameterization modeling, S3-bridge deck system 3D parameterization modeling, S4-pier 3D parameterization modeling, S5-combination of the beam, the railroad track, the bridge deck system and the pier to form the bridge 3D model, and S6-introduction of the bridge model into the virtual environment.

The invention discloses a deformation control method of a high-pier and long-span bridge track of a railway. A high-pier and long-span bridge model is analyzed through a finite element method, and whether track deformation meets the specification requirements or not is calculated under a wind load, a temperature change, a driving condition and / or a braking condition. According to the deformation control method of the high-pier and long-span bridge track of the railway, track deformation on a high-pier and long-span bridge is actively researched and analyzed for the problem of shortage of research on the track deformation of an existing long-span bridge; a good method for controlling the track deformation is provided; the problem of the track deformation can be significantly improved; and the traffic security and smoothness of a train are improved.

The invention relates to a joint-simulation-based on-bridge ballastless turnout structure system and a dynamic analysis method thereof. The dynamic analysis method of the joint-simulation-based on-bridge ballastless turnout structure system comprises the following steps of firstly finishing the model establishment of a balastless track and bridge structure by utilizing the ABAQUS software; secondly finishing the model establishment of a vehicle and a turnout by utilizing the SIMPACK software; finally establishing rigid-flexible coupled wheel-track contact relationship in the SIMPACK software to form a vehicle-turnout-bridge coupling system model, and realizing the connection and the coupled solution of a vehicle model, a turnout model and a bridge model. According to the joint-simulation-based on-bridge ballastless turnout structure system and the dynamic analysis method thereof, which are disclosed by the invention, the complex wheel-track contact relationship of a turnout zone is fully considered, and the model establishment of a turnout and bridge structure is finished according to the actual state to the greatest extent so as to ensure the detailedness, the completion and the accuracy of the model; the model establishment is finished by utilizing the business software, so that the production, the design and the application are convenient, and the improvement is remarkable by comparing the modeling method provided by the invention with the traditional modeling method.

The invention relates to a method for building road assembly type bridge disease and reinforcement models by utilizing Dynamo. The method comprises the following steps: dismantling a road assembly type bridge structure according to functions; defining geometrical features of essential features of each type of component as parameters, and building correspoding Revit-family file database, wherein family files are named as structural types and features of the family files; building a bridge structure database; compiling Dynamo program code for building the bridge model; building a bridge diseasefamily library based on Revit; building a bridge disease information database; compiling Dynamo program code for building the disease model; building a bridge reinforcement component family library based on Revit; building a bridge reinforcement information database; compiling the Dynamo program code for building the reinforcement model. According to the method disclosed by the invention, by combining the structure characteristics of the road prefabricated assembly type bridge, a corresponding quick parameterized modeling method is built, the modeling process of the bridge model is simplified,and the modeling efficiency is improved.

A wind tunnel testing system for annular rail models, vehicle models and bridge models includes a wind tunnel model test box (1) provided with at least one opening, wherein the space between opposite vertical side walls in one group on the wind tunnel model test box (1) is a wind tunnel testing zone; two opposite holes (18) are formed in the opposite vertical side walls in one group; a bridge model (5) is arranged between the two opposite holes (18); a rail is arranged on the bridge model (5); a vehicle model (4) for test is movably connected onto a rail (2); the rail (2) includes a guiding section rail (2) and a testing section rail (3); the guiding section rail (2) and the testing section rail (3) are connected from end to end to form an annular rail provided with an annular loop; the annular rail penetrates the two holes (18) simultaneously, or the annular rail simultaneously passes by the two holes (18) and the outer part of the wind tunnel model test box (1). According to the invention, the vehicle model can run on the rail in a cyclic manner, and the testing data obtained through testing more conforms to the actual condition.

The present invention discloses a real-time monitoring system for bridge construction. The system comprises: a data collection device, wherein, after collecting real-time data by covering a plurality of sensors of a constructed part of a bridge, the data collection device is used for processing real-time data and obtaining processed data corresponding to each sensor; a server, wherein the server is used for receiving and storing the processed data of each sensor transmitted by the data collection device; and a network display platform, wherein sensor models are arranged at a corresponding position in a bridge model established on the network display platform to an actual bridge, and the network display platform is used for receiving processed data of each sensor transmitted by the server, corresponding the processed data to the sensor model respectively, and generating a real-time three-dimensional model based on the bridge model. According to the system disclosed by the present invention, data is automatically collected all the time by using the data collection device, and result data is visualized in the real-time three-dimensional model by setting the sensor model corresponding to the actual bridge on the network display platform, so that bridge construction information is displayed more intuitively.

The invention relates to a vehicle-rail-bridge shaking table test device with a circular rail. The vehicle-rail-bridge shaking table test device comprises a vehicle model (3) used for simulating a high-speed rail train, a circulatory rail used for providing a circulatory running track for the vehicle model (3), a shaking table (4) used for simulating bridge earthquake states from the bottom of a bridge model (4), a guide section rail support (6) used for supporting the end of the circulatory rail from the bottom, and a test data acquiring device (12). An anti-loosening mechanism used for preventing the vehicle model (3) from falling off the circulatory rail is arranged between the vehicle model (3) and the circulatory rail.

The bridge simulation detection method and system used for experimental teaching provided by the present invention, the method includes: establishing a bridge model, and arranging a data acquisition module for collecting bridge state data on the bridge model, preparing a load test loading scheme, and making the bridge according to the loading scheme Under different load conditions, collect the bridge state data of the bridge under different load conditions, process the bridge state data, and obtain bridge detection results; the bridge simulation detection method and system for experimental teaching in the present invention can be used The designed bridge model can conveniently assemble various bridges. The invention has the advantages of simple structure and low cost, is suitable for large-scale teaching and popularization, and can be well used for teaching of bridge static and dynamic load tests and health monitoring.

The invention provides a bridge vertical direction and torsion coupling large amplitude free vibration wind tunnel test device and belongs to the technical field of bridge wind tunnel test devices. The device includes a rigid test model, a lightweight rigid rod, a lightweight rigid round hub, a first string, linear tension springs and a second string. According to the device, the free vertical direction and torsion large amplitude coupling free vibration of a bridge model can be achieved, a vertical spring only has telescopic deformation without lateral tilting, and a problem that a spring isobviously tilted and the linear torsional rigidity cannot be guaranteed in a conventional free vibration test device does not exist. The device is simple and is easy to install, an initial angle of attack is easy to adjust, and due to the rolling friction between the strings and the hub, the mechanical damping ratio is very low.

The invention relates to the technical field of bridge engineering, and provides a cable-stayed bridge cable force optimization method, a device, equipment and a readable storage medium. The method comprises the steps of building a cable-stayed bridge model through space finite element analysis software; solving a load combination working condition based on the cable force set and the static loadworking condition; performing internal force analysis on the cable-stayed bridge model based on the load combination working condition to obtain a structure response result; whether the cable-stayed bridge model conforms to a reasonable bridge forming state or not is checked based on the structure response result, if yes, cable-stayed bridge cable force optimization is completed, and if not, a control point set is screened out according to the structure response result; solving an influence matrix corresponding to the control point set based on the load combination working condition; exportingthe influence matrix and the cable force set out of space finite element analysis software; and optimizing the cable force set based on the influence matrix, and returning the optimized cable force set to the space finite element analysis software to iteratively optimize the cable force set until the cable-stayed bridge model conforms to a reasonable bridge forming state, so that the cable forceoptimization efficiency and difficulty of the cable-stayed bridge can be well considered.

The invention provides a web page jump control method and system. The method comprises the steps that after a web page is loaded, a webview of the web page is acquired, and context information of the page is acquired through the webview; the webview is used to encapsulate a bridge model, and the encapsulated bridge model is utilized to perform assignment on the context information; and the webview calls a preset click information response method gotoOther in the bridge model by receiving user click information, and corresponding jump operation is executed according to parameters of gotoOther. Through the method, the bridge model with the set click information response method gotoOther is encapsulated through the webview of the page, the corresponding web page jump operation is executed by receiving the user click information, and therefore mutual jump between an original page and a non-original page on a mobile terminal is realized.

Counters are implemented within an 802.1Q VLAN (Virtual Local Area Network) bridge model to assist a network administrator in diagnosing network problems associated with the dynamic registration of VLANs. Such counters are able to count the number of dynamic VLANs propagated through a bridging device, and for monitoring the maximum number of VLANs ever simultaneously configured on a bridge device.

The invention discloses a windmill rail bridge coupling model and an on-bridge travelling crane criterion formulation method. The windmill rail bridge model comprises a wind submodel, a train submodel, a rail submodel and a bridge submodel, wherein each submodel forms wind-train-rail-bridge coupling system through the mutual function of a windmill, a wind bridge, a wheel rail and a bridge rail; anexplicit and implicit mixed integral method is adopted to solve the dynamic response of a system, a relation curve of a train speed-wind speed threshold value is obtained according to a correspondingevaluation index so as to formulate a corresponding travelling crane criterion. The windmill rail bridge coupling model has the beneficial effects that a dynamic wheel rail contact relation between wheel rails is fully considered, the modeling of the static and dynamic aerodynamic characteristics of the rail structure, the bridge, the wind and the axle system is finished according to a practicalstate, the refinement, the integrity and the accuracy of the model are improved so as to obtain a reliable and true system dynamic response value, a scientific basis can be provided for formulating the safety evaluation and the travelling crane criterion of on-bridge travelling crane under gale atmosphere, and therefore, the windmill rail bridge model has a high theoretical value and engineering application prospect.

The invention relates to a remote bridge structure monitoring and prewarning method based on an Internet of things technology. The remote bridge structure monitoring and prewarning method comprises the following steps of: (1) building a bridge model and calculating to obtain the dynamic deflection of a beam; (2) continuously acquiring data of monitored points to obtain a sequence [u] of the dynamic deflection, and carrying out forecast evaluation on the performances of a bridge system by using a specific mode based on a chaotic system, wherein the step (2) comprises the substeps of: (2.1) calculating a maximum Lyapunov index of the sequence [u]; (2.2) calculating the delay time and an optimal embedded dimension; and (2.3) carrying out fitting and contrast on the reconfigured chaotic time sequence to realize health monitoring and prewarning of a bridge structure. The remote bridge structure monitoring and prewarning method is used for analyzing the monitored data and precast evaluation on the future working state of a bridge to realize prewarning.

The invention discloses a method for identifying damage position and damage degree of truss bridge based on neural network. The method comprises the steps of constructing the bridge sample data, usinga finite element method to establish a bridge model, and obtaining the simulated frequency data of a bridge in good condition and under different damage conditions; calculating the frequency change ratio, frequency square change ratio and frequency change rate according to the simulated frequency data of the bridge in good condition and under different damage conditions; determining the topologyof the network, using a BP neural network to determine the number of neurons in each layer and initialize the weights and thresholds of the neural network at the same time; training the neural networkby the elastic gradient method combined with a genetic algorithm and testing by test samples, and obtaining the trained neural network; inputting the real-time frequency data of the bridge into the trained neural network to realize the identification of the damage location and damage degree of the bridge. The method of the invention has the advantages of fast calculation speed and great engineering application value for the maintenance and reinforcement of the actual bridges.

The invention relates to a force and pressure measurement model of a bridge. The model comprises a rectangular suspension frame, a suspension frame cover outside the suspension frame and a force measurement mechanism for measuring force of the suspension frame, wherein the force measurement mechanism comprises an axial force sensor, a plurality of vertical force sensors and a plurality of lateral force sensors, the axial force sensor is arranged at the end part of the suspension frame and located in the same straight line with a center line of the wide side of the suspension frame, the vertical force sensors are vertically arranged at the bottom of the suspension frame, and the lateral force sensors are arranged on one or two side surfaces of the suspension frame and parallel to the wide side direction of the suspension frame. According to the force and pressure measurement model of the bridge, the force sensors are distributed in multiple directions, so that force in all directions can be measured; disturbance elimination components are arranged between each force sensor and the suspension frame, so that the force in all directions can be transmitted to corresponding force sensors as much as possible, the accuracy of measured force is greatly improved, and aerodynamic force of the bridge model is obtained accurately; and rectangular end blocks arranged at two ends of the suspension frame are taken as compensation sections, accordingly, the end effect can be avoided, and a flow field of a suspension section can be close to a two-dimensional flow as much as possible.

The invention discloses a wind tunnel test device for a vehicle model moving on a bridge based on precision linear slide rails. The wind tunnel test device comprises the vehicle model, force measurement balances, speed sensors, a traction system and a bridge model supported by brackets, and further comprises the precision linear slide rails fixedly arranged on the bridge surface of the bridge model, wherein slide devices connected with the traction system are arranged on the precision linear slide rails and fixed in the vehicle model; the force measurement balances are fixed on the slide devices through force measurement brackets; the speed sensors are arranged on the bridge surface of the bridge model. The precision linear slide rails and slide blocks are adopted, so that vibration of the vehicle model in a moving process can be greatly reduced, high-precision stable traveling of the vehicle model can be realized, the force measurement balances can be enabled to more accurately test pneumatic force of the vehicle model, and six-component force under different wind directions, different wind speeds and different vehicle speeds also can be tested; the system is low in cost, simple in principle, easy to operate and very wide in application range.

The invention relates to a bridge safety early warning method based on PSInSAR technology. The bridge safety early warning method comprises steps that S1: by adopting a bundling mode PSInSAR, bridge deformation information is extracted; S2: a PSInSAR coherence evaluation model based on a bridge model is established; S3: based on the bridge deformation key points of the SAR technology, the random deformation rule thereof is acquired; S4: by combining with the bridge deformation key point deformation information acquired by the PSInSAR, according to a bridge construction norm, a multidimensionalrandom variable theory is adopted, and bridge safety early warning criteria based on high definition remote sensing data are established. Problems such as high costs of equipment required by manual detection, heavy workload, and long detection period are solved, and early warning of bridge safety problems can be effectively carried out.

The invention provides a bridge monitoring method, and relates to a bridge monitoring technology. The bridge monitoring method comprises the steps that a three-dimensional terrain model is establishedbased on topographic information obtained by aerial photography, the three-dimensional terrain model is integrated with a pre-constructed three-dimensional bridge model in a system, thereby obtaininga three-dimensional scene model, bridge disease information obtained by tour inspection is integrated with the three-dimensional scene model in the system, the bridge disease information is displayedon the three-dimensional scene model to obtain a three-dimensional disease model, and a specific disease type and disease degree of a bridge can be obtained by visually analyzing the three-dimensional disease model; a maintenance scheme can be obtained by analyzing the three-dimensional disease model, thereby greatly reducing the time of the maintenance and scheme designing. Compared with the prior art, the bridge monitoring method has the advantages that a maintenance personnel can be helped to quickly find the disease type and disease degree, the maintenance scheme can be timely given, andthe efficiency of bridge maintenance is greatly improved.