A stack bridge main girder deflection inversion method based on double-inclination measurement

Abstract

The present application relates to the technical field of calculation method, and specifically relates to a kind of stack bridge main beam deflection inversion method based on double inclination measurement, the three-dimensional finite element model of stack bridge is established according to stack bridge design parameter, the three-dimensional finite element model of stack bridge is simulated under standard control load working condition and simulation parameter is obtained, initial conversion coefficient is calculated according to simulation parameter, sensor is pasted on the surface of stack bridge main beam, the working parameter of stack bridge is detected by sensor, when stack bridge enters effective load steady state interval, sensor continuously acquires stack bridge parameter, iterative calculation is carried out according to stack bridge parameter, effective conversion coefficient is obtained after iteration, the vertical deflection of stack bridge is inverted by stack bridge parameter and effective conversion coefficient, a kind of stack bridge main beam deflection inversion method based on double inclination measurement can generate new conversion coefficient according to the inclination data of stack bridge each time work, to provide accurate stack bridge main beam deflection value.

Description

Technical Field

[0001] This invention relates to the field of computational methods, specifically to a method for inverting the deflection of the main beam of a trestle bridge based on dual-tilt angle measurement. Background Technology

[0002] In large construction trestle bridges and temporary steel bridges, displacement gauges are often not installed because the working surface is underneath. In engineering, the "double-tilt difference method" is used to indirectly monitor deflection. However, common inversion methods suffer from low accuracy due to empirical formulas: the actual load is a multi-axle moving vehicle (not a concentrated force), leading to a systematic underestimation of deflection by 20%-40%, posing a risk of safety oversight. Therefore, existing methods, once the coefficients are set, are fixed and cannot be corrected using subsequent measurements, resulting in unreliable long-term accuracy. This paper proposes a deflection inversion method for the main beam of a trestle bridge based on double-tilt measurement. Summary of the Invention

[0003] To address the technical problems existing in the prior art, the present invention provides a method for inverting the deflection of the main beam of a trestle bridge based on dual tilt angle measurement.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for inverting the deflection of the main girder of a trestle bridge based on dual-tilt angle measurement, comprising the following steps:

[0005] Step S1: Establish a three-dimensional finite element model of the trestle bridge based on its design parameters. Under standard control load conditions, perform static simulation on the three-dimensional finite element model of the trestle bridge and obtain simulation parameters. Calculate the initial transformation coefficients based on the simulation parameters. ;

[0006] Step S2: Attach sensors to the surface of the main beam of the trestle and detect the working parameters of the trestle through the sensors. When the trestle enters the effective load steady state range, the sensors continuously collect the trestle parameters.

[0007] Step S3: Perform iterative calculations based on the bridge parameters. After the second iteration, an effective conversion coefficient is obtained. ;

[0008] Step S4, using bridge parameters and effective conversion coefficients Invert the vertical deflection of the trestle bridge.

[0009] Preferably, in step S1, the simulation parameters include:

[0010] Simulated values ​​of deflection at mid-span of the main girder of the trestle bridge Simulated instantaneous tilt angle at a position one-quarter the length of the main beam of the trestle bridge Simulated value of instantaneous tilt angle at three-quarters length of the main beam of the trestle bridge ;

[0011] Initial conversion coefficients are established based on the acquired simulation parameters. The calculation formula:

[0012] ;

[0013] Calculate and obtain the initial conversion coefficients .

[0014] Preferably, in step S2, the sensor is a tilt sensor, which is set at one-quarter and three-quarters of the length of the main beam of the trestle bridge. The tilt sensor is used to collect the instantaneous tilt angle data of the main beam of the trestle bridge.

[0015] Preferably, in step S2, the criterion for determining the effective load steady-state range is: within a continuous period of time T, the absolute values ​​of the readings of both tilt sensors are greater than the preset working threshold of the tilt sensors.

[0016] Preferably, in step S2, when the trestle enters the effective load steady-state range, the tilt sensor collects data in real time. Instantaneous tilt angle data at one-quarter length of the main girder of the trestle bridge Instantaneous tilt angle data at three-quarters length of the main beam of the trestle bridge .

[0017] Preferably, step S3 includes:

[0018] Step S31, based on the initial conversion coefficients ,calculate Mid-span deflection value of the trestle :

[0019] ;

[0020] Step S32: The theoretical deflection at the mid-span of the trestle bridge under steady-state load is zero. Based on this, a residual signal is established to reflect the deviation between the current model output and the physical truth. The calculation formula:

[0021] ;

[0022] Calculate and obtain the residual signal .

[0023] Preferably, step S3 further includes:

[0024] Step S33, the residual signal With the preset deflection convergence threshold Comparison:

[0025] like Then the initial conversion coefficients are considered to be The initial conversion coefficients are accurate enough. Use it directly as the final result;

[0026] like Then, the gradient descent method is used to update the initial transformation coefficients. , obtained the The conversion coefficients after the next iteration :

[0027]

[0028] In the formula, The learning rate, ranging from 0.01 to 0.1, is used to control the update speed. This represents the number of iterations.

[0029] Preferably, in step S33, when the number of iterations... hour, , This represents the initial conversion coefficient. .

[0030] Preferably, step S3 further includes:

[0031] Step S34, convert the conversion coefficients Substitute into step S31, and repeat steps S31 to S33 until the residual signal is obtained. satisfy Output the final conversion coefficients. .

[0032] Preferably, step S4 includes:

[0033] Step S41, based on Instantaneous tilt angle data at one-quarter length of the main girder of the trestle bridge Instantaneous tilt angle data at three-quarters length of the main beam of the trestle bridge ,Establish Estimate of mid-span deflection of the trestle bridge at any time The calculation formula:

[0034] ;

[0035] Step S42, Output Estimate of mid-span deflection of the trestle bridge at any time .

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] 1. This invention establishes a method for inverting the deflection of the main beam of a trestle bridge based on dual tilt angle measurement. It can iteratively generate new conversion coefficients based on the tilt angle data of the trestle bridge each time it is in operation, realize the real-time correction of the coefficients, and provide accurate deflection values ​​of the main beam of the trestle bridge. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments, which illustrate the above and other technical features and advantages of the present invention. However, the following embodiments are merely preferred embodiments of the present invention and are not exhaustive.

[0040] Example:

[0041] like Figure 1 As shown, this invention provides a method for inverting the deflection of the main girder of a trestle bridge based on dual-inclination angle measurement, comprising the following steps:

[0042] Step S1: Establish a three-dimensional finite element model of the trestle bridge based on its design parameters. Under standard control load conditions, perform static simulation on the three-dimensional finite element model of the trestle bridge and obtain simulation parameters, including:

[0043] Simulated values ​​of deflection at mid-span of the main girder of the trestle bridge Simulated instantaneous tilt angle at a position one-quarter the length of the main beam of the trestle bridge Simulated value of instantaneous tilt angle at three-quarters length of the main beam of the trestle bridge ;

[0044] Initial conversion coefficients are established based on the acquired simulation parameters. The calculation formula:

[0045] ;

[0046] Calculate and obtain the initial conversion coefficients ;

[0047] Step S2: Sensors are attached to the surface of the main beam of the trestle bridge to detect its operating parameters. The sensors used are tilt sensors, positioned at one-quarter and three-quarters of the length of the main beam. These tilt sensors collect instantaneous tilt angle data of the main beam. When the trestle bridge enters its effective load steady-state range, the criterion for determining this range is: within a continuous time period T, the absolute values ​​of the readings from both tilt sensors are greater than the preset operating threshold of the tilt sensors. When the trestle bridge enters its effective load steady-state range, the tilt sensors collect data in real time. Instantaneous tilt angle data at one-quarter length of the main girder of the trestle bridge Instantaneous tilt angle data at three-quarters length of the main beam of the trestle bridge ;

[0048] Step S3: Perform iterative calculations based on the bridge parameters. After the second iteration, an effective conversion coefficient is obtained. ;

[0049] Step S31, based on the initial conversion coefficients ,calculate Mid-span deflection value of the trestle :

[0050] ;

[0051] Step S32: The theoretical deflection at the mid-span of the trestle bridge under steady-state load is zero. Based on this, a residual signal is established to reflect the deviation between the current model output and the physical truth. The calculation formula:

[0052] ;

[0053] Calculate and obtain the residual signal ;

[0054] Step S33, the residual signal With the preset deflection convergence threshold Comparison:

[0055] like Then the initial conversion coefficients are considered to be The initial conversion coefficients are accurate enough. Use it directly as the final result;

[0056] like Then, the gradient descent method is used to update the initial transformation coefficients. , obtained the The conversion coefficients after the next iteration :

[0057]

[0058] In the formula, The learning rate, ranging from 0.01 to 0.1, is used to control the update speed. Let be the number of iterations. hour, , This represents the initial conversion coefficient. ;

[0059] Step S34, convert the conversion coefficients Substitute into step S31, and repeat steps S31 to S33 until the residual signal is obtained. satisfy Output the final conversion coefficients. .

[0060] Step S4, using bridge parameters and effective conversion coefficients The vertical deflection of the trestle bridge was inverted based on... Instantaneous tilt angle data at one-quarter length of the main girder of the trestle bridge Instantaneous tilt angle data at three-quarters length of the main beam of the trestle bridge ,Establish Estimate of mid-span deflection of the trestle bridge at any time The calculation formula:

[0061] ;

[0062] Output Estimate of mid-span deflection of the trestle bridge at any time .

[0063] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. A method for inverting the deflection of the main girder of a trestle bridge based on dual-inclination angle measurement, characterized in that, Includes the following steps: Step S1: Establish a three-dimensional finite element model of the trestle bridge based on its design parameters. Under standard control load conditions, perform static simulation on the three-dimensional finite element model of the trestle bridge and obtain simulation parameters. Calculate the initial transformation coefficients based on the simulation parameters. ; Simulation parameters include: simulated deflection value at the mid-span of the main girder of the trestle bridge. Simulated instantaneous tilt angle at a position one-quarter the length of the main beam of the trestle bridge Simulated value of instantaneous tilt angle at three-quarters length of the main beam of the trestle bridge ; Initial conversion coefficients are established based on the acquired simulation parameters. The calculation formula: ； Calculate and obtain the initial conversion coefficients ; Step S2: Attach sensors to the surface of the main beam of the trestle and detect the working parameters of the trestle through the sensors. When the trestle enters the effective load steady state range, the sensors continuously collect the trestle parameters. The sensor is a tilt sensor, which is set at one-quarter and three-quarters of the length of the main beam of the trestle bridge. The tilt sensor is used to collect the instantaneous tilt angle data of the main beam of the trestle bridge. The criterion for determining the effective load steady-state range is: within a continuous period of time... Inside, the absolute values ​​of the readings of both tilt sensors are greater than the preset operating threshold of the tilt sensors; When the trestle enters the effective load steady-state range, the tilt sensor collects data in real time. Instantaneous tilt angle data at one-quarter length of the main girder of the trestle bridge Instantaneous tilt angle data at three-quarters length of the main beam of the trestle bridge ; Step S3: Perform iterative calculations based on the bridge parameters. After the second iteration, an effective conversion coefficient is obtained. ; Step S3 includes: Step S31, based on the initial conversion coefficients ,calculate Mid-span deflection value of the trestle : ； Step S32: The theoretical deflection at the mid-span of the trestle bridge under steady-state load is zero. Based on this, a residual signal is established to reflect the deviation between the current model output and the physical truth. The calculation formula: ； Calculate and obtain the residual signal ; Step S33, the residual signal With the preset deflection convergence threshold Comparison: like Then the initial conversion coefficients are considered to be The initial conversion coefficients are accurate enough. Use it directly as the final result; like Then, the gradient descent method is used to update the initial transformation coefficients. , obtained the The conversion coefficients after the next iteration : ； In the formula, The learning rate, ranging from 0.01 to 0.1, is used to control the update speed. This represents the number of iterations. Step S34, convert the conversion coefficients Substitute into step S31, and repeat steps S31 to S33 until the residual signal is obtained. satisfy Output the final conversion coefficients. ; Step S4, using bridge parameters and effective conversion coefficients Invert the vertical deflection of the trestle bridge.

2. The method for inverting the deflection of the main girder of a trestle bridge based on dual-inclination angle measurement as described in claim 1, characterized in that, In step S33, when the number of iterations... hour, , This represents the initial conversion coefficient. .

3. The method for inverting the deflection of the main girder of a trestle bridge based on dual-inclination angle measurement as described in claim 1, characterized in that, Step S4 includes: Step S41, based on Instantaneous tilt angle data at one-quarter length of the main girder of the trestle bridge Instantaneous tilt angle data at three-quarters length of the main beam of the trestle bridge ,Establish Estimate of mid-span deflection of the trestle bridge at any time The calculation formula: ； Step S42, Output Estimate of mid-span deflection of the trestle bridge at any time .

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