Arch rib node stress monitoring method and device applied to long-span basket handle type arch bridge

Abstract

The application discloses an arch rib node stress monitoring method and device applied to a large-span basket handle type arch bridge, belongs to the field of bridge engineering, and comprises the following steps: S1, constructing an arch rib space analysis model; based on design drawings and material parameters of the basket handle type arch bridge, a refined finite element model containing all arch rib nodes and connecting components is established, a whole coupling analysis model capable of reflecting spatial collaborative stress of the arch rib is constructed by introducing constraint conditions; S2, sensor arrangement; based on the whole analysis model, key stress monitoring nodes are dynamically identified and selected through multi-working condition load simulation, and sensors are arranged at the key nodes to monitor multi-dimensional mechanical response signals of the nodes. The arch rib node stress monitoring method and device applied to the large-span basket handle type arch bridge can accurately monitor arch rib node stress, data transmission is reliable, stress and service life can be dynamically evaluated, the method and device are adapted to characteristics of the basket handle type arch bridge, early warning is timely, and bridge operation and maintenance safety and economy are considered.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering technology, and in particular to a method and device for monitoring stress at arch rib nodes of long-span basket arch bridges. Background Technology

[0002] Long-span basket-arch bridges are widely used in major transportation projects spanning rivers and valleys due to their advantages of strong spanning capacity, rational structural stress distribution, and aesthetically pleasing architecture. The arch rib, as the core load-bearing component of this type of bridge, connects the arch rib segments and other load-bearing components at its joints, serving as a crucial hub for stress transfer and also one of the weakest areas in terms of structural mechanical performance. During long-term bridge operation, the arch rib joints must withstand the coupled effects of multiple factors, including vehicle loads, temperature changes, wind loads, and material aging, making them prone to stress concentration and fatigue damage accumulation. Failure to monitor and address these issues in a timely manner can lead to serious safety accidents such as joint cracking or even structural collapse. Therefore, accurate and efficient stress monitoring of the arch rib joints is crucial.

[0003] Currently, stress monitoring of bridge arch rib joints can be mainly divided into two categories: traditional contact monitoring and numerical simulation analysis. Traditional contact monitoring often uses equipment such as strain gauges and resistive sensors, and the sensor placement is determined by experience or simple structural analysis. However, this method has significant limitations: on the one hand, the arch ribs of long-span basket-arch bridges are spatially inclined, and the stress on the joints has strong spatial coordination characteristics, making it difficult to accurately capture key stress areas based on experience, which can easily lead to monitoring blind spots or wasted resources; on the other hand, the data collected by the sensors is susceptible to environmental electromagnetic interference and temperature drift, and single wired or wireless transmission methods are prone to data loss and delay in complex bridge site environments, making it difficult to guarantee the integrity and real-time performance of the monitoring data. Summary of the Invention

[0004] The purpose of this invention is to address the problems of existing stress monitoring methods for bridge arch rib nodes, which struggle to accurately capture key stress areas and suffer from data loss and delays in complex bridge site environments using only wired or wireless transmission methods. Therefore, this invention proposes a stress monitoring method and device for arch rib nodes of long-span basket-type arch bridges.

[0005] To achieve the above objectives, the present invention employs the following technology: a method and device for monitoring the stress at arch rib nodes of long-span basket-arch bridges, comprising the following steps: S1. Constructing the spatial analysis model of the arch rib: Based on the design drawings and material parameters of the basket arch bridge, a refined finite element model containing all arch rib nodes and their connecting components is established. By introducing constraints, an overall coupled analysis model that can reflect the spatial co-force of the arch rib is constructed. S2. Sensor Arrangement: Based on the overall analysis model, key stress monitoring nodes are dynamically identified and selected through multi-condition load simulation, and sensors are arranged at the key nodes to monitor the multi-dimensional mechanical response signals of the nodes. S3. Data Acquisition and Transmission: The sensor data is acquired, filtered, and amplified. The data is transmitted to the monitoring center using a hybrid transmission method that combines wired and wireless methods. S4. Data Analysis and Processing: Based on the finite element analysis model and combined with real-time collected stress data, the stress distribution of the arch rib node is dynamically simulated and analyzed to obtain the stress field distribution of the node under different working conditions. Based on the stress field distribution, the stress concentration factor and fatigue damage index of the arch rib node are calculated to evaluate the stress state and fatigue life of the node. S5. Real-time early warning: Set the stress safety threshold for the arch rib node. When the monitored stress of the arch rib node reaches the preset threshold, the early warning mechanism is triggered.

[0006] As a further description of the above technical solution: In step S1, the introduced constraints include the stiffness contribution of the cross bracing between the arch ribs and the K bracing, as well as the nonlinear boundary conditions of the arch foot consolidation.

[0007] As a further description of the above technical solution: In step S2, the key stress monitoring nodes include at least the arch foot area, the arch rib and cross brace connection nodes at the quarter span and three-quarter span, and the intersection node of the K brace.

[0008] As a further description of the above technical solution: In step S2, the arranged sensors adopt a combination of high-precision fiber optic grating sensors and intelligent strain gauges. The sensors are arranged in multiple dimensions along the longitudinal, transverse and vertical directions of the arch rib. In areas where the stress changes are more intense, the sensor spacing is set to 0.5-1 meter, and in areas where the stress changes are relatively gentle, the sensor spacing is increased to 1-2 meters.

[0009] As a further description of the above technical solution: In step S3, data acquisition is performed by acquiring stress data measured by each sensor in real time through a wireless communication module arranged in the sensor. During data transmission, fiber optic transmission is used in areas that are close to the monitoring center and where cabling is convenient, while wireless transmission modules based on 5G technology are used in areas where cabling is difficult or where mobile monitoring is required.

[0010] As a further description of the above technical solution: In step S4, based on the actual structural parameters and material properties of the long-span basket arch bridge, the finite element analysis model is updated, and the stress data collected in real time is input into the finite element analysis model as boundary conditions to perform transient dynamic analysis and obtain the stress field distribution of the nodes at different times.

[0011] As a further description of the above technical solution: In step S5, the warning threshold is set with 80%-90% of the bridge design load as the upper limit of stress. When the stress reaches 80% of the upper limit threshold, a yellow warning is issued; when the stress reaches 90% of the upper limit threshold, an orange warning is issued; and when the stress exceeds the upper limit threshold, a red warning is issued.

[0012] A stress monitoring device for arch rib nodes of long-span basket arch bridges, wherein the device uses the monitoring method described in any one of the above-mentioned methods to monitor the stress at the arch rib nodes.

[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. By constructing a refined finite element model of the spatial collaborative stress of the arch ribs, and combining multi-condition load simulation to dynamically identify key nodes, the sensor “targeted placement” is realized, solving the problem that empirical placement is difficult to accurately capture the key stress of spatial stress nodes, and is prone to blind spots or waste. 2. Data quality is improved through filtering and amplification preprocessing. A hybrid wired and wireless transmission method is adopted to solve the problems of data being susceptible to interference and data loss and delay in complex environments when using a single transmission method. This ensures data integrity and real-time performance, providing reliable support for subsequent analysis. Attached Figure Description

[0014] Figure 1 A principle block diagram provided according to an embodiment of the present invention is shown. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Reference Figure 1 The method and apparatus for monitoring the stress at the arch rib joints of a long-span basket-arch bridge provided in this embodiment include the following steps: S1. Constructing the spatial analysis model of the arch rib: Based on the design drawings and material parameters of the basket arch bridge, a refined finite element model containing all arch rib nodes and their connecting components is established. By introducing constraints, an overall coupled analysis model that can reflect the spatial co-force of the arch rib is constructed. S2. Sensor Arrangement: Based on the overall analysis model, key stress monitoring nodes are dynamically identified and selected through multi-condition load simulation, and sensors are arranged at the key nodes to monitor the multi-dimensional mechanical response signals of the nodes. S3. Data Acquisition and Transmission: The sensor data is acquired, filtered, and amplified. The data is transmitted to the monitoring center using a hybrid transmission method that combines wired and wireless methods. S4. Data Analysis and Processing: Based on the finite element analysis model and combined with real-time collected stress data, the stress distribution of the arch rib node is dynamically simulated and analyzed to obtain the stress field distribution of the node under different working conditions. Based on the stress field distribution, the stress concentration factor and fatigue damage index of the arch rib node are calculated to evaluate the stress state and fatigue life of the node. S5. Real-time early warning: Set the stress safety threshold for the arch rib node. When the monitored stress of the arch rib node reaches the preset threshold, the early warning mechanism is triggered.

[0017] In step S1, the introduced constraints include the stiffness contributions of the cross braces between the arch ribs and the K-braces, as well as the nonlinear boundary conditions of the arch foot consolidation. By introducing the stiffness contributions of the cross braces between the arch ribs and the K-braces, and the nonlinear boundary conditions of the arch foot consolidation, the actual stress state of the arch rib nodes can be more realistically reproduced, improving the accuracy of the model in simulating spatial collaborative stress, and laying a reliable foundation for subsequent key node identification and stress analysis.

[0018] In step S2, the key stress monitoring nodes include at least the arch foot area, the connection nodes between the arch ribs and cross braces at the quarter span and three-quarter span, and the intersection nodes of the K-braces. The sensors are arranged using a combination of high-precision fiber optic grating sensors and intelligent strain gauges. The sensors are deployed in multiple dimensions along the longitudinal, transverse, and vertical directions of the arch ribs. In areas with more drastic stress changes, the sensor spacing is set to 0.5-1 meter; in areas with relatively gentle stress changes, the sensor spacing is increased to 1-2 meters. The arch foot area, the connection nodes between the arch ribs and cross braces at the quarter span and three-quarter span, and the intersection nodes of the K-braces are areas of stress concentration and crucial to structural safety. Ensuring no blind spots in monitoring core risk points and differentiating sensor spacing according to the severity of stress changes ensures the integrity of monitoring data while avoiding resource waste, achieving an optimal balance between monitoring efficiency and cost.

[0019] In step S3, data acquisition involves real-time acquisition of stress data measured by each sensor through a wireless communication module located within the sensor. During data transmission, fiber optic transmission is used in areas that are close to the monitoring center and where cabling is convenient, while wireless transmission modules based on 5G technology are used in areas where cabling is difficult or where mobile monitoring is required.

[0020] Fiber optic transmission is used in areas with short distances and convenient cabling to ensure high bandwidth, low latency and anti-interference capabilities for data transmission, ensuring data stability in core areas. 5G wireless transmission is used in areas with difficult cabling or mobile monitoring to overcome cabling limitations in complex bridge environments, covering the entire bridge monitoring scenario. At the same time, 5G technology supports high-speed remote transmission, avoiding data loss or delay, ultimately achieving blind-spot-free, high-efficiency and high-stability data transmission across the entire bridge.

[0021] In step S4, the finite element analysis model is updated based on the actual structural parameters and material properties of the long-span basket-arch bridge. Real-time collected stress data is input as boundary conditions into the finite element analysis model for transient dynamic analysis, yielding the stress field distribution at the nodes at different times. By using real-time collected stress data as boundary conditions, the finite element model dynamically responds to actual stress changes in the bridge, rather than relying on fixed load assumptions. Transient dynamic analysis can capture the dynamic stress field distribution at different times, accurately reproducing the instantaneous response and evolution of node stress under load changes, providing more realistic dynamic data support for subsequent stress concentration factor calculations and fatigue life assessments.

[0022] In step S5, the warning threshold is set with 80%-90% of the bridge design load as the upper limit of stress. When the stress reaches 80% of the upper limit threshold, a yellow warning is issued; when the stress reaches 90% of the upper limit threshold, an orange warning is issued; and when the stress exceeds the upper limit threshold, a red warning is issued.

[0023] A stress monitoring device for arch rib nodes applied to long-span basket arch bridges is characterized in that the device uses the monitoring method described in any one of the above-mentioned methods to monitor the stress at the arch rib nodes.

[0024] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for monitoring stress at arch rib nodes in long-span basket-arch bridges, characterized in that, Includes the following steps: S1. Constructing the spatial analysis model of the arch rib: Based on the design drawings and material parameters of the basket arch bridge, a refined finite element model containing all arch rib nodes and their connecting components is established. By introducing constraints, an overall coupled analysis model that can reflect the spatial co-force of the arch rib is constructed. S2. Sensor Arrangement: Based on the overall analysis model, key stress monitoring nodes are dynamically identified and selected through multi-condition load simulation, and sensors are arranged at the key nodes to monitor the multi-dimensional mechanical response signals of the nodes. S3. Data Acquisition and Transmission: The sensor data is acquired, filtered, and amplified. The data is transmitted to the monitoring center using a hybrid transmission method that combines wired and wireless methods. S4. Data Analysis and Processing: Based on the finite element analysis model and combined with real-time collected stress data, the stress distribution of the arch rib node is dynamically simulated and analyzed to obtain the stress field distribution of the node under different working conditions. Based on the stress field distribution, the stress concentration factor and fatigue damage index of the arch rib node are calculated to evaluate the stress state and fatigue life of the node. S5. Real-time early warning: Set the stress safety threshold for the arch rib node. When the monitored stress of the arch rib node reaches the preset threshold, the early warning mechanism is triggered.

2. The method for monitoring the stress at the arch rib joints of a long-span basket-arch bridge according to claim 1, characterized in that, In step S1, the introduced constraints include the stiffness contribution of the cross bracing between the arch ribs and the K-bracing, as well as the nonlinear boundary conditions of the arch foot consolidation.

3. The method for monitoring the stress at the arch rib joints of a long-span basket-arch bridge according to claim 1, characterized in that, In step S2, the key stress monitoring nodes include at least the arch foot area, the arch rib and cross brace connection nodes at the quarter span and three-quarter span, and the intersection node of the K brace.

4. The method for monitoring the stress at the arch rib joints of a long-span basket-arch bridge according to claim 3, characterized in that, In step S2, the sensors are arranged using a combination of high-precision fiber optic grating sensors and smart strain gauges. The sensors are arranged in multiple dimensions along the longitudinal, transverse and vertical directions of the arch rib. In areas where stress changes are more intense, the sensor spacing is set to 0.5-1 meter, and in areas where stress changes are relatively gentle, the sensor spacing is increased to 1-2 meters.

5. The method for monitoring the stress at the arch rib joints of a long-span basket-arch bridge according to claim 1, characterized in that, In step S3, data acquisition involves real-time acquisition of stress data measured by each sensor through a wireless communication module located within the sensor. During data transmission, fiber optic transmission is used in areas that are close to the monitoring center and where cabling is convenient, while wireless transmission modules based on 5G technology are used in areas where cabling is difficult or where mobile monitoring is required.

6. The method for monitoring the stress at the arch rib joints of a long-span basket-arch bridge according to claim 1, characterized in that, In step S4, the finite element analysis model is updated based on the actual structural parameters and material properties of the long-span basket arch bridge. The stress data collected in real time is input into the finite element analysis model as boundary conditions to perform transient dynamic analysis and obtain the stress field distribution of the nodes at different times.

7. The method for monitoring the stress at the arch rib joints of a long-span basket-arch bridge according to claim 1, characterized in that, In step S5, the warning threshold is set with 80%-90% of the bridge design load as the upper limit of stress. When the stress reaches 80% of the upper limit threshold, a yellow warning is issued; when the stress reaches 90% of the upper limit threshold, an orange warning is issued; and when the stress exceeds the upper limit threshold, a red warning is issued.

8. A stress monitoring device for arch rib nodes of long-span basket-arch bridges, characterized in that, The device uses the monitoring method described in any one of claims 1-7 to monitor the stress at the arch rib joint.

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