A refined evaluation method for manufacturing deviation of stress-free configuration of steel trusses

Abstract

The present invention discloses a method for fine-grained evaluation of manufacturing deviation of stress-free configuration of steel truss beams in the field of steel beam manufacturing technology, comprising placing a manufactured large steel truss beam section according to a standard, and respectively taking a plurality of characteristic bolt holes on the large steel truss beam section; measuring each of the characteristic bolt holes to obtain a reference three-dimensional coordinate and a measurement value of a hole diameter; establishing a finite element simulation calculation model of the large steel truss beam section according to a design drawing of the large steel truss beam section; obtaining a simulation value of the reference three-dimensional coordinate and the hole diameter of each of the characteristic bolt holes according to the finite element simulation calculation model; and performing fine-grained evaluation of deviation according to the measurement value and simulation value of the reference three-dimensional coordinate and the hole diameter of each of the characteristic bolt holes. The present invention comprehensively considers the geometric configuration of the large steel truss beam section, hole group information and the stress state thereof, thereby realizing fine-grained evaluation of manufacturing deviation of stress-free configuration of steel truss beams.

Description

Technical Field

[0001] The invention relates to the technical field of steel beam manufacturing, and in particular to a refined evaluation method for manufacturing deviation of a stress-free configuration of a steel truss beam. Background Art

[0002] The bridge industry is developing towards intelligence, refinement, high efficiency and prefabrication. Steel trusses are widely used because of their good structural form and the ability to provide independent upper and lower lanes. With the development of large lifting equipment, large steel truss sections are often used, such as Figure 1 As shown, the construction process of overall hoisting and bolting and welding connection is carried out. Since two adjacent large steel truss girder segments are first positioned by punching nails into the bolt holes on the plate bundle at the joint, they are gradually replaced with bolts for connection, and then the bridge deck and other connecting parts are welded. The bolt holes on the plate bundle at the joint are composed of bolt holes located on the node plate 6 at the end of the steel truss girder and bolt holes on the splicing plate 7 used to connect the two large steel truss girder segments as a whole. The splicing plate is a connecting plate that clamps the node plate inside and outside. Therefore, the manufacturing deviation of the stress-free configuration of the steel truss girder (including the geometric configuration of the steel truss girder (geometric dimensions of the upper and lower chords, relative position relationship of the chords), bolt hole position, and hole diameter) determines the local linear shape (relative linear shape between two adjacent segments) and the overall linear shape (the overall linear shape composed of all beam segments) of the bridge after the final completion, avoiding the occurrence of error divergence and the like.

[0003] At present, the industry only uses methods such as making temporary measuring points at the node position of the steel truss (the intersection of the steel beam vertical rod and the chord rod) with awl guns, and using the total station to measure the spatial three-dimensional coordinates of the measuring points to evaluate the manufacturing configuration and quality of the steel truss. The above method introduces errors in the production of measuring points, the measurement errors of the prisms at the measuring points, and the errors of the total station itself are also at the millimeter level; in addition, the results of the above measurement ignore the non-node positions, especially the most important hole group information, which is not comprehensive, and the accuracy does not match the large span and refinement.

[0004] The manufacturing of steel trusses is based on design drawings, where the dimensions and hole group information (hole position, hole diameter) in the design drawings are the dimensions and hole group information when the rod is in a stress-free state and does not undergo stress deformation. The actual manufacturing sequence of large sections of steel trusses is cutting plates, assembling into rods, drilling bolt holes in node plates at the ends of rods, assembling rods into trusses, assembling into large sections with bridge decks, measuring large sections of steel beams, and conducting manufacturing quality assessments.

[0005] Starting from the above-mentioned "assembly into rods", the rods are located on a small number of piers. At this time, the rods are in a stress state. At this time, the hole making datum of the node plate bolt hole at the end of the rod includes the stress deformation of the chord. In addition, from "assembling rods into trusses" to the final "measuring large sections of steel beams and conducting manufacturing quality assessment", they are all constructed on the tire frame of multiple piers. At this time, the steel truss structure is also in a stress state and has stress deformation. In the measurement of "measuring large sections of steel beams and conducting manufacturing quality assessment", only the geometric dimensions of the large sections of steel trusses are measured, and the hole group information at the end of the chord is not included. However, since the adjacent large sections are connected by bolt welding with splicing plates and high bolts, the manufacturing deviation of the bolt hole group will cause relative rotation angles and installation of additional secondary internal forces at the splicing point, thereby providing a divergent initial error for the subsequent steel beam errors. Therefore, the measurement of the hole group information of the node plate is crucial and cannot be ignored.

[0006] In summary, the traditional practice in the industry does not monitor the hole group information, the monitoring accuracy is low, and the stress deformation caused by the temporary support and the frame support pier on the steel beam is not considered. The measurement results are directly compared with the geometric dimensions in the drawings, which is incomplete and unreasonable. In other words, even if the error between the measured results and the geometric dimensions in the drawings is small, or even zero, once the steel beam is transported to the site for installation, there will still be unpredictable errors in the absence of temporary support piers. The errors include the influence of elastic deformation on the geometric dimensions and hole group information of the steel beam on the one hand, and the manufacturing error of the node plate hole group information on the other hand. This has led to the lack of refinement in the evaluation of the manufacturing deviation of the stress-free configuration of steel trusses in the past. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a method for finely evaluating the manufacturing deviation of the stress-free configuration of a steel truss girder, which comprehensively considers the geometric configuration of large sections of the steel truss girder, hole group information and the stress state thereof, thereby achieving finely evaluating the manufacturing deviation of the stress-free configuration of the steel truss girder.

[0008] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0009] In a first aspect, the present invention provides a method for finely evaluating manufacturing deviation of a stress-free configuration of a steel truss, comprising:

[0010] Placing the manufactured steel truss girder large sections according to the standard, and taking a plurality of characteristic bolt holes on the steel truss girder large sections respectively;

[0011] Measuring each of the characteristic bolt holes to obtain reference three-dimensional coordinates and hole diameter measurement values;

[0012] Establishing a finite element simulation calculation model of the steel truss large section according to the design drawings;

[0013] Acquire the simulation values ​​of the three-dimensional coordinates and the hole diameter of each characteristic bolt hole according to the finite element simulation calculation model;

[0014] A refined deviation evaluation is performed based on the measured values ​​and simulated values ​​of the reference three-dimensional coordinates and the hole diameter of each characteristic bolt hole.

[0015] Optionally, placing the manufactured steel truss large sections according to standards includes:

[0016] Establishing a foundation to support the large steel truss girder section, and ensuring that the foundation does not settle or deform before and after the large steel truss girder section is placed;

[0017] Corresponding to the supporting points of the large steel truss girder sections, a corresponding number of temporary piers of the same height are arranged on the foundation, and it is ensured that the temporary piers do not deform before and after the large steel truss girder sections are placed;

[0018] The large steel truss girder segment is placed on the temporary pier according to the position of its supporting point to form a stress state.

[0019] Optionally, the characteristic bolt holes are selected from the bolt holes on the node plates and splicing plates of the large sections of the steel trusses.

[0020] Optionally, the step of measuring each of the characteristic bolt holes to obtain reference three-dimensional coordinates and hole diameter measurement values ​​includes:

[0021] Take at least 4 measuring points on the perimeter measuring plane of the characteristic bolt hole to be measured, and place the standard measuring target balls on the measuring points respectively;

[0022] The three-dimensional coordinates of the contact points between the standard measuring target ball and the characteristic bolt hole circumference measuring plane are measured by a laser tracker, and the plane equation of the characteristic bolt hole circumference measuring plane is fitted;

[0023] Placing the standard measurement target ball in the characteristic bolt hole, and ensuring that the standard measurement target ball fits tightly with the characteristic bolt hole;

[0024] The three-dimensional coordinates of the center of the standard measurement target sphere are measured by a laser tracker, and the three-dimensional coordinates of the center of the characteristic bolt hole on the characteristic bolt hole circumferential plane and the hole diameter are calculated according to the three-dimensional coordinates of the center of the sphere and the plane equation;

[0025] The three-dimensional coordinates of the center of the characteristic bolt hole on the circumferential plane of the characteristic bolt hole are used as the reference three-dimensional coordinates of the characteristic bolt hole.

[0026] Optionally, the deviation refinement evaluation method further includes:

[0027] After the manufactured large steel truss girder segment is placed according to the standard, the ambient temperature is obtained, and the ambient temperature is input into the finite element simulation calculation model for model correction.

[0028] Optionally, the performing a refined deviation evaluation based on the measured values ​​and simulated values ​​of the reference three-dimensional coordinates and the aperture of each of the characteristic bolt holes includes:

[0029] Unifying the measured value and the simulated value of the reference three-dimensional coordinate of the characteristic bolt hole into the same coordinate system, and calculating the hole position deviation of the characteristic bolt hole in the same coordinate system;

[0030] The aperture deviation of the characteristic bolt hole is calculated according to the measured value and the simulated value of the aperture of the characteristic bolt hole.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention provides a refined evaluation method for the manufacturing deviation of the stress-free configuration of steel trusses, which grasps that the control focus of large sections of steel trusses is the bolt hole group information and stress-free configuration deviation at the node plate, rather than the data of the measuring point at the intersection of the steel truss chord and the vertical rod currently used in the industry, ignoring the deviation of the bolt hole group information at the node plate, and ignoring the structural deviation between the node plate and the measuring point at the intersection of the steel truss chord and the vertical rod, and not considering the stress deformation caused by the temporary support. As a result, the evaluation indicators are not comprehensive and reasonable, and the measurement error is large, and the data support provided for the site is not strong enough.

[0033] The laser tracker can be used to measure the bolt holes at the ends of steel trusses with a higher test accuracy than other methods in the industry. The manufacturing error inversion method based on the theoretical deformation under the support state consistent with the actual finite element calculation model can be used to more comprehensively and accurately evaluate and analyze the manufacturing deviation of large sections of steel trusses. The hole position deviation and hole diameter deviation of the bolt holes at the node plate can be used as the analysis basis for the linear deviation of adjacent large sections of steel beams after assembly, and the error transmission mechanism can be analyzed. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is an example diagram of a large section of a steel truss provided in the background technology of the present invention;

[0035] Figure 2 It is a flow chart of a method for fine evaluation of manufacturing deviation of stress-free configuration of steel trusses provided in an embodiment of the present invention;

[0036] Figure 3 The present invention Figure 1 An enlarged schematic diagram of the mid-node plate or spliced ​​plate;

[0037] Figure 4is a diagram showing the calculation principle of the three-dimensional coordinates of the center of a circle and the aperture provided by an embodiment of the present invention;

[0038] Figure 5 It is a schematic diagram of structural deformation in a finite element simulation calculation model provided by an embodiment of the present invention;

[0039] The markings in the figure are:

[0040] 1-Large section of steel truss; 2-Upper chord; 3-Diagonal rod; 4-Vertical rod; 5-Lower chord; 6-Node plate; 7-Splicing plate; 8-Temporary pier; 9-Characteristic bolt hole; 10-General bolt hole; 11-Peripheral measurement plane of characteristic bolt hole; 12-Standard measurement target sphere; 13-Center of standard measurement target sphere. DETAILED DESCRIPTION

[0041] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0042] Embodiment 1:

[0043] like Figure 2 As shown, the present invention provides a method for fine evaluation of manufacturing deviation of stress-free configuration of steel trusses, comprising the following steps:

[0044] Step S1, placing the manufactured large steel truss girder segments according to the standard, and taking a plurality of characteristic bolt holes on the large steel truss girder segments respectively.

[0045] Specifically in this embodiment, placing the manufactured steel truss girder large segments according to the standard includes:

[0046] Step S1.1, build a foundation to support the large steel truss girder section, and ensure that the foundation does not settle or deform before and after the large steel truss girder section is placed.

[0047] Step S1.2: corresponding to the supporting points of the large steel truss girder sections, arrange a corresponding number of temporary piers of the same height on the foundation, and ensure that the temporary piers do not deform before and after the large steel truss girder sections are placed; the supporting points are usually located at the intersection of the vertical rod and the lower chord rod.

[0048] Step S1.3, placing the large steel truss girder segment on the temporary pier according to the position of its support point to form a stress state.

[0049] Specifically in this embodiment, the characteristic bolt holes are selected from the bolt holes on the node plate and the splicing plate of the large section of the steel truss girder, such as Figure 3 shown.

[0050] Step S2: measuring each characteristic bolt hole to obtain the reference three-dimensional coordinates and the measured values ​​of the hole diameter.

[0051] Specifically in this embodiment, measuring each characteristic bolt hole to obtain the reference three-dimensional coordinates and the measured values ​​of the hole diameter includes:

[0052] Step S2.1, select at least 4 measuring points on the perimeter measuring plane of the characteristic bolt hole to be measured, and place the standard measuring target balls on the measuring points respectively.

[0053] Step S2.2, measuring the three-dimensional coordinates of the contact point between the standard measurement target sphere and the characteristic bolt hole circumference measurement plane by a laser tracker, and fitting the plane equation of the characteristic bolt hole circumference measurement plane;

[0054] The plane equation is:

[0055] ;

[0056] Where A, B, C are the components of the normal vector, A, B, C, D are all constants, (x, y, z) are the coordinates of the point in the plane, and the plane equation can be fitted and solved by substituting more than 4 coordinates.

[0057] Specifically in this embodiment, the laser tracker uses a FARO laser tracker, and the laser distance measuring unit is installed at the bottom of the tracker host. The laser beam passes through the hollow vertical axis and the two-dimensional reflector to point to the target ball to achieve tracking measurement of the target. Two circular grating encoders installed on the two-dimensional tracking turntable realize angle measurement, and the spatial coordinates of the target ball are obtained by the principle of spatial polar coordinate conversion, with a measurement accuracy of 16um + 0.8um / m. The FARO laser tracker is a mature product and will not be introduced in detail here.

[0058] Step S2.3, placing the standard measurement target ball in the characteristic bolt hole, and ensuring that the standard measurement target ball fits tightly with the characteristic bolt hole.

[0059] Step S2.4, measure the three-dimensional coordinates of the center of the target sphere using a laser tracker measurement standard, and calculate the three-dimensional coordinates of the center of the characteristic bolt hole on the characteristic bolt hole circumferential plane and the hole diameter based on the three-dimensional coordinates of the center and the plane equation.

[0060] like Figure 4 As shown in the figure, since the radius R of the standard measuring target sphere is known, a simple mathematical operation can be performed to obtain the distance from the center of the standard measuring target sphere to the perimeter plane of the characteristic bolt hole. :

[0061] ;

[0062] In the formula, The three-dimensional coordinates of the center of the standard measurement target sphere;

[0063] Radius of the feature bolt hole :

[0064] ;

[0065] Step S2.5, taking the three-dimensional coordinates of the center of the characteristic bolt hole on the characteristic bolt hole circumferential plane as the reference three-dimensional coordinates of the characteristic bolt hole.

[0066] Step S3: establishing a finite element simulation calculation model of the large steel truss segment according to the design drawings.

[0067] In the process of establishing its finite element simulation calculation model, nodes are established at the center of all bolt holes at the ends of the large sections of the steel truss to form a group of bolt hole centers on the node plate corresponding to the drawings. Similarly, nodes are established at the characteristic points of the head and tail ends of the rods (such as the intersections between the vertical rods, chord rods, and diagonal rods) to simulate the geometric characteristics of the structure in a refined manner. A support unit is established at the intersection of the vertical rod and the lower chord rod in the model to simulate the actual support state on site, and the finite element software is used to analyze and obtain the structural deformation corresponding to the actual stress state.

[0068] like Figure 5 As shown, it is a schematic diagram of the structural deformation in the finite element simulation calculation model established in this embodiment.

[0069] In order to avoid the influence of thermal expansion and contraction on the refined evaluation of deviation, the manufactured large steel truss sections are placed according to the standard, the ambient temperature is obtained, and the ambient temperature is input into the finite element simulation calculation model for model correction.

[0070] Step S4, obtaining the simulation values ​​of the reference three-dimensional coordinates and the hole diameter of each characteristic bolt hole according to the finite element simulation calculation model.

[0071] Step S5, performing a refined deviation evaluation based on the measured values ​​and simulated values ​​of the reference three-dimensional coordinates and the aperture of each characteristic bolt hole.

[0072] Specifically in this embodiment, the deviation refinement evaluation is performed based on the measured values ​​and simulated values ​​of the reference three-dimensional coordinates and the aperture of each characteristic bolt hole, including:

[0073] Unify the measured value and simulation value of the characteristic bolt hole reference 3D coordinates into the same coordinate system, and calculate the hole position deviation of the characteristic bolt hole in the same coordinate system:

[0074] ;

[0075] In the formula, is the hole position deviation of the characteristic bolt hole, are the measured and simulated values ​​of the 3D coordinates of the characteristic bolt hole reference.

[0076] According to the measured value and simulation value of the characteristic bolt hole diameter, the diameter deviation of the characteristic bolt hole is calculated:

[0077] ;

[0078] In the formula, is the diameter deviation of the characteristic bolt hole, are the measured and simulated values ​​of the characteristic bolt hole diameter.

[0079] Furthermore, based on the measured and simulated values ​​of the characteristic bolt hole reference three-dimensional coordinates, the geometric dimensions between the characteristic bolt holes at the head and tail ends of the upper or lower chord can be calculated, that is, the spacing deviation between the characteristic bolt holes at the head and tail ends; the deviations of the relative mileage x, axis y, and height difference z between each member, as well as the errors in the length, width, and height of the large section of the steel truss.

[0080] In summary, this embodiment proposes:

[0081] (1) The measurement needs to take into account the stress deformation caused by the temporary support state during manufacturing. A method for inferring the manufacturing error of the theoretical deformation under the support state consistent with the actual one calculated by finite element method is given.

[0082] (2) A measurement method based on a laser tracker and a target ball was proposed to improve the measurement accuracy. It also realized the measurement of the position and diameter of the bolt holes on the node plate, and gave the measurement and calculation methods. It realized the collection of hole group information and could comprehensively analyze and evaluate the entire length of the chord and the large section of the steel beam itself. It can also be expanded to analyze and evaluate the linear shape of multiple steel beams after assembly, which increases the comprehensiveness and improves the accuracy. It can also realize the analysis of the error transmission mechanism and provide data support.

[0083] (3) It is proposed that the key evaluation indicators for large sections of steel trusses should be:

[0084] a. Geometric dimensions of the characteristic bolt holes at the beginning and end of the upper and lower chords;

[0085] b. Bolt hole position deviation;

[0086] c. Bolt hole diameter deviation;

[0087] d. The deviations of the relative distance x, axis y, height difference z between each member, as well as the errors in length, width and height of the large section of the steel truss.

[0088] In other optional implementations, those skilled in the art may choose not to be limited to the above-mentioned key evaluation indicators.

[0089] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0090] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0091] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0092] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A refined evaluation method for manufacturing deviation of stress-free configuration of steel trusses, characterized in that: include: Placing the manufactured steel truss girder large sections according to the standard, and taking a plurality of characteristic bolt holes on the steel truss girder large sections respectively; Measuring each of the characteristic bolt holes to obtain reference three-dimensional coordinates and hole diameter measurement values; Establishing a finite element simulation calculation model of the steel truss large section according to the design drawings; Acquire the simulation values ​​of the three-dimensional coordinates and the hole diameter of each characteristic bolt hole according to the finite element simulation calculation model; Performing a refined deviation evaluation based on the measured values ​​and simulated values ​​of the three-dimensional coordinates and the aperture of each characteristic bolt hole; The step of placing the manufactured large steel truss girder segments according to the standard comprises: Establishing a foundation to support the large steel truss girder section, and ensuring that the foundation does not settle or deform before and after the large steel truss girder section is placed; Corresponding to the supporting points of the large steel truss girder sections, a corresponding number of temporary piers of the same height are arranged on the foundation, and it is ensured that the temporary piers do not deform before and after the large steel truss girder sections are placed; Placing the large steel truss girder segment on the temporary pier according to the position of its supporting point to form a stress state; The step of measuring each of the characteristic bolt holes to obtain the reference three-dimensional coordinates and the measured values ​​of the hole diameter includes: Take at least 4 measuring points on the perimeter measuring plane of the characteristic bolt hole to be measured, and place the standard measuring target balls on the measuring points respectively; The three-dimensional coordinates of the contact points between the standard measuring target ball and the characteristic bolt hole circumference measuring plane are measured by a laser tracker, and the plane equation of the characteristic bolt hole circumference measuring plane is fitted; Placing the standard measurement target ball in the characteristic bolt hole, and ensuring that the standard measurement target ball fits tightly with the characteristic bolt hole; The three-dimensional coordinates of the center of the standard measurement target sphere are measured by a laser tracker, and the three-dimensional coordinates of the center of the characteristic bolt hole on the characteristic bolt hole circumferential plane and the hole diameter are calculated according to the three-dimensional coordinates of the center of the sphere and the plane equation; The three-dimensional coordinates of the center of the characteristic bolt hole on the circumferential plane of the characteristic bolt hole are used as the reference three-dimensional coordinates of the characteristic bolt hole.

2. The method for evaluating the manufacturing deviation of the stress-free configuration of a steel truss according to claim 1 is characterized in that: The characteristic bolt holes are selected from the bolt holes on the node plates and the splicing plates of the large sections of the steel truss beams.

3. The method for evaluating the manufacturing deviation of the stress-free configuration of a steel truss according to claim 1 is characterized in that: The deviation refinement evaluation method further includes: After the manufactured large steel truss girder segment is placed according to the standard, the ambient temperature is obtained, and the ambient temperature is input into the finite element simulation calculation model for model correction.

4. The method for evaluating the manufacturing deviation of the stress-free configuration of a steel truss according to claim 1 is characterized in that: The refined evaluation of deviation according to the measured values ​​and simulated values ​​of the three-dimensional coordinates and the aperture of each characteristic bolt hole comprises: Unifying the measured value and the simulated value of the reference three-dimensional coordinate of the characteristic bolt hole into the same coordinate system, and calculating the hole position deviation of the characteristic bolt hole in the same coordinate system; The aperture deviation of the characteristic bolt hole is calculated according to the measured value and the simulated value of the aperture of the characteristic bolt hole.

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