Method for obtaining vortex-induced force parameters of a bridge pre-suspended cable and measuring device

Abstract

The application belongs to the field of road and bridge engineering, and discloses a method for obtaining vortex-induced force parameters of a bridge predetermined sling. Firstly, the axis of the bridge predetermined sling and the sling plane where the sling plane structure line perpendicular to the axis is obtained. Then, based on the environmental wind direction, the sling plane obtains the downstream displacement of the sling and the cross-flow displacement of the sling, and obtains the downstream vortex vibration frequency of the sling and the cross-flow vortex vibration frequency of the sling. Then, the multi-order vibration mode function and the multiple vibration mode frequencies of the predetermined sling are obtained, and the downstream vortex vibration mode function and the cross-flow vortex vibration mode function of the predetermined sling are obtained. Finally, the downstream vortex vibration motion equation and the cross-flow vortex vibration motion equation of the predetermined sling are established, and the downstream vortex-induced force parameters and the cross-flow vortex-induced force parameters of the predetermined sling are obtained. The application also discloses a device for measuring vortex-induced force parameters, which can better implement the method for obtaining vortex-induced force parameters of a bridge predetermined sling.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of road and bridge engineering, and particularly relates to a method for obtaining vortex-induced force parameters of a predetermined bridge sling and a measuring device. BACKGROUND

[0002] Sling vortex-induced resonance is a wind-induced vibration disease that frequently occurs on long-span suspension bridges in recent years. Lightly, sling vortex-induced resonance may cause fatigue damage of the sling and discomfort of the people crossing the bridge; heavily, sling vortex-induced resonance will significantly affect the durability and safety of the suspension bridge structure, so it is very important and necessary to measure and analyze the sling vortex-induced resonance phenomenon of the suspension bridge.

[0003] At present, in the process of measuring and analyzing the sling vortex-induced resonance, the vortex-induced force parameters of the sling are important parameters for analysis, and in actual engineering practice, it is difficult to obtain the vortex-induced force parameters of the sling, and the difficulty lies in that the sling vortex vibration often presents multi-degree-of-freedom vibration in the wind direction and the lateral wind direction, and it is difficult to determine the relative position relationship between the sling movement and the incoming flow wind direction, so it is difficult to accurately position the direction of the sling vibration sensor and restore the actual movement trajectory of the sling. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a method for obtaining vortex-induced force parameters of a predetermined bridge sling and a measuring device, which can conveniently determine the relative position relationship between the movement of the bridge sling and the environmental wind direction, accurately determine the actual movement trajectory of the bridge sling, and further obtain accurate vortex-induced force parameters of the sling.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0006] A method for obtaining vortex-induced force parameters of a predetermined bridge sling, the bridge having a plurality of mutually parallel slings including the predetermined sling, characterized in that it comprises the following steps:

[0007] Step S1: setting a sling plane construction line perpendicular to the axis of the predetermined sling;

[0008] Step S2: rotating the sling plane construction line about the axis of the predetermined sling so that the sling plane construction line passes through the axis of the adjacent sling of the predetermined sling,

[0009] Step S3: taking the plane in which the axis of the predetermined sling and the sling plane construction line are located as a sling plane, obtaining the acceleration of the predetermined sling along the sling plane towards the adjacent sling as a sling plane acceleration, and obtaining the acceleration of the predetermined sling along the normal direction of the sling plane as a sling plane normal acceleration;

[0010] Step S4: obtaining a streamwise displacement of the predetermined sling along the environmental wind direction and a cross-stream displacement of the predetermined sling perpendicular to the streamwise displacement of the predetermined sling based on the environmental wind direction, the in-plane acceleration of the sling and the in-plane normal acceleration of the sling;

[0011] Step S5: obtaining a streamwise vortex vibration frequency of the sling based on the streamwise displacement of the sling and a cross-stream vortex vibration frequency of the sling based on the cross-stream displacement of the sling;

[0012] Step S6: obtaining a multi-order mode function of the predetermined sling and a plurality of mode frequencies corresponding to the multi-order mode function, and obtaining a streamwise vortex vibration mode function and a cross-stream vortex vibration mode function of the predetermined sling according to a fitting result of the streamwise vortex vibration frequency, the cross-stream vortex vibration frequency and the plurality of mode frequencies;

[0013] Step S7: respectively establishing a streamwise vortex vibration motion equation and a cross-stream vortex vibration motion equation of the predetermined sling;

[0014] Step S8: obtaining a streamwise vortex excitation force parameter of the predetermined sling based on the streamwise vortex vibration mode function and the streamwise vortex vibration motion equation of the sling, and obtaining a cross-stream vortex excitation force parameter of the predetermined sling based on the cross-stream vortex vibration mode function and the cross-stream vortex vibration motion equation of the sling.

[0015] Preferably, in step S1, a configuration laser beam is set, and an optical path of the configuration laser beam is a sling plane configuration line.

[0016] Preferably, step S4 comprises the following sub-steps:

[0017] Step S4-1: obtaining a combined vector acceleration by vector combination of the in-plane acceleration of the sling and the in-plane normal acceleration of the sling;

[0018] Step S4-2: decomposing the combined vector acceleration along the environmental wind direction and a direction perpendicular to the environmental wind direction to obtain a streamwise acceleration of the sling and a cross-stream acceleration of the sling;

[0019] Step S4-3: obtaining the streamwise displacement of the sling and the cross-stream displacement of the sling by time-frequency transformation of a time domain curve of the streamwise acceleration of the sling and a time domain curve of the cross-stream acceleration of the sling.

[0020] Preferably, in step S5, the streamwise vortex vibration frequency of the sling is a peak value of a frequency domain curve of the streamwise displacement of the sling, and the cross-stream vortex vibration frequency of the sling is a peak value of a frequency domain curve of the cross-stream displacement of the sling.

[0021] Preferably, step S6 comprises the following sub-steps:

[0022] Step S6-1: establishing a sling finite element model according to a mass matrix and a stiffness matrix of the predetermined sling;

[0023] Step S6-2: Obtain the multi-order mode shape functions and the plurality of mode frequencies based on the finite element model of the sling;

[0024] Step S6-3: Fit the curve of the along-wind vortex vibration frequency of the sling with the curves of the plurality of mode frequencies respectively, and take the mode shape function corresponding to the mode frequency with the highest fitting degree as the along-wind vortex vibration mode shape function; fit the vortex vibration frequency of the sling in the cross-wind direction with the plurality of mode frequencies respectively, and take the mode shape function corresponding to the mode frequency with the highest fitting degree as the cross-wind vortex vibration mode shape function.

[0025] Preferably, step S7 comprises the following sub-steps:

[0026] Step S7-1: Establish the along-flow vortex vibration motion equation:

[0027]

[0028] m is the mass per meter of the predetermined sling, y1 represents the along-flow displacement of the sling, ε represents the sling damping ratio of the predetermined sling, ω1 is the along-flow vortex vibration frequency of the sling, is the along-flow vortex excitation force coefficient of the predetermined sling, D is the structural characteristic width, U is the wind speed, and ρ is the air density,

[0029] Step S7-2: Dimensionless the equation in step S7-1:

[0030]

[0031] s = Ut / D, η1 = y1 / D, K0 = ω1D / U,

[0032] Step S7-3: Establish the cross-flow vortex vibration motion equation:

[0033]

[0034] y2 represents the cross-flow displacement of the sling, ω2 is the cross-flow vortex vibration frequency of the sling, is the cross-flow vortex excitation force coefficient of the predetermined sling,

[0035] Step S7-4: Dimensionless the equation in step S7-3:

[0036]

[0037] η2 = y2 / D, K0 = ω2D / U.

[0038] Further, step S8 comprises the following sub-steps:

[0039] Step S8-1: Obtain the vortex-induced resonance response relationship η(x, s) based on the vortex vibration mode shape function:

[0040] η(x, s) = Φ(x)v(s)

[0041] Φ(x) is a vortex vibration mode function, and v(s) is a modal coordinate;

[0042] Step S8-2: the vortex-induced resonance response relationship is associated with the in-line vortex vibration equation and the cross-flow vortex vibration equation respectively, and the following is obtained:

[0043]

[0044]

[0045] is the in-line generalized mass of the predetermined sling, Φ1(x) is the in-line vortex vibration mode function, and v1(s) is the in-line modal coordinate, is the cross-flow generalized mass of the predetermined sling, Φ2(x) is the cross-flow vortex vibration mode function, and v2(s) is the cross-flow modal coordinate, and L is the length of the predetermined sling, is the initial phase of the cross-flow vortex-induced force parameter, is the initial phase of the in-line vortex-induced force parameter,

[0046] Step S8-3: the following is calculated by least square fitting:

[0047] A vortex-induced force parameter measuring device for implementing the vortex-induced force parameter acquisition method of the bridge predetermined sling described above, characterized in that it comprises: a fixing part which is detachably arranged on the predetermined sling as described above; a measuring part which is arranged on the fixing part and comprises a laser emitter and an acceleration sensor which are both located near the predetermined sling, the laser emitter is used to emit a structured laser beam as described above, the emission direction of the laser emitter is perpendicular to the axis of the predetermined sling, and the acceleration sensor is used to acquire the in-plane acceleration and the normal in-plane acceleration of the cable as described above; and a control part which is signal-connected with the acceleration sensor.

[0048] Further, the fixing part comprises a detachable pair of circular arc clamping barrels which tightly embrace the predetermined sling from both sides of the predetermined sling.

[0049] Still further, the circular arc clamping barrel has an outwardly convex moving guide rail, the plane where the moving guide rail is located is perpendicular to the axis of the predetermined sling, and the moving guide rail extends along the same curvature path as the circular arc clamping barrel, and the measuring part further comprises a moving fixing member and a bearing base fixed on the moving fixing member, the moving fixing member has a moving groove and a top stop screw, the moving groove is movably arranged along the extension path of the moving guide rail in cooperation with the moving guide rail, the top stop screw is arranged through the moving fixing member and extends into the moving groove, the top stop screw is used to tightly top the moving fixing member on the moving guide rail, and the laser emitter and the acceleration sensor are both fixed on the bearing base.

[0050] Compared with the prior art, the present application has the following advantages:

[0051] 1. According to the method for obtaining the vortex-induced force parameters of the predetermined cable of the bridge of the present application, firstly, the axis of the predetermined cable of the bridge and the cable plane where the cable plane configuration line is located are obtained, then, based on the environmental wind direction, the cable plane obtains the in-stream displacement amount of the cable and the cross-stream displacement amount of the cable, and the in-stream vortex vibration frequency of the cable and the cross-stream vortex vibration frequency of the cable are obtained, then, the multi-order vibration mode function and the multiple vibration mode frequencies of the predetermined cable are obtained, and the in-stream vortex vibration mode function and the cross-stream vortex vibration mode function of the predetermined cable are obtained, finally, the in-stream vortex vibration motion equation and the cross-stream vortex vibration motion equation of the predetermined cable are established, and the in-stream vortex-induced force parameters and the cross-stream vortex-induced force parameters of the predetermined cable are obtained, since the axis of the predetermined cable and the axis of the adjacent cable are always located in the cable plane, and the cable plane is determined by the cable plane configuration line, therefore, by setting the vibration sensor with the cable plane configuration line, the direction of the vibration of the predetermined cable of the bridge can be accurately positioned, thus, the relative position relationship between the motion of the cable of the bridge and the environmental wind direction can be conveniently determined, so as to accurately determine the actual motion track of the cable of the bridge, and then the accurate vortex-induced force parameters of the cable are obtained.

[0052] 2. According to the present application, the laser beam is set, and the light path of the laser beam is the cable plane configuration line, thus, the cable plane is established by the laser beam, so as to conveniently set the cable plane configuration line.

[0053] 3. According to the vortex-induced force parameter measuring device of the present application, the device comprises a fixing part, a measuring part and a control part, the fixing part is detachably arranged on the predetermined cable, the measuring part is arranged on the fixing part, and comprises a laser emitter and an acceleration sensor, the laser emitter is used to emit the configuration laser beam, and the acceleration sensor is used to obtain the cable plane acceleration and the cable plane normal acceleration, thus, the vortex-induced force parameter measuring device can better implement the method for obtaining the vortex-induced force parameters of the predetermined cable of the bridge. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 It is a schematic diagram of the steps of the method for obtaining the vortex-induced force parameters of the predetermined cable of the bridge of the embodiment of the present application;

[0055] Figure 2 It is a schematic diagram of the steps of the method for obtaining the vortex-induced force parameters of the predetermined cable of the bridge of the embodiment of the present application;

[0056] Figure 3 It is a side view of Figure 2 ;

[0057] Figure 4 It is a side view of Figure 2A top view of

[0058] Figure 5 is a three-dimensional schematic diagram of a fixing portion according to an embodiment of the present invention;

[0059] Figure 6 A schematic perspective view of a measuring unit according to an embodiment of the present invention;

[0060] Figure 7 Schematic diagram of an implementation of a device for measuring vortex force parameters according to an embodiment of the present invention.

[0061] In the figure: S100, method for obtaining vortex-induced force parameters of predetermined bridge slings, 100, device for measuring vortex-induced force parameters, 10, fixing part, 11, arc clamp, 111, movable guide rail, 112, connecting ear, 20, measuring part, 21, movable fixing part, 211, movable groove, 212, top stop screw hole, 22, bearing base, 23, laser emitter, 24, acceleration sensor, S, predetermined sling, S1, adjacent sling, L1, laser beam optical path. DETAILED DESCRIPTION

[0062] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the following embodiments, in conjunction with the accompanying drawings, specifically illustrate the method for obtaining and measuring the vortex-induced force parameters of the predetermined bridge suspension cable of the present invention. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0063] like Figure 1 As shown, the method S100 for obtaining the vortex-induced force parameters of the predetermined slings of the beam in this embodiment, wherein the bridge has a plurality of mutually parallel slings including the predetermined slings, comprises the following steps:

[0064] Step S1: setting a cable plane construction line perpendicular to the axis of the predetermined sling.

[0065] Specifically, by setting a construction laser beam and making the optical path of the construction laser beam the cable plane construction line, in this embodiment, the emission source of the construction laser beam is located on the predetermined suspension cable of the bridge, and the emission direction of the emission source is always perpendicular to the predetermined suspension cable of the bridge.

[0066] Step S2: rotating the cable plane construction line with the axis of the predetermined sling as the rotation axis, so that the cable plane construction line passes through the axis of the sling adjacent to the predetermined sling.

[0067] In this embodiment, the emission source of the construction laser beam is rotated at a predetermined sling of the bridge, and the surface of the sling adjacent to the predetermined sling is observed. When the construction laser beam has an irradiation spot on the adjacent sling, the cable plane construction line passes through the axis of the sling adjacent to the predetermined sling.

[0068] Step S3: taking the axis of the predetermined sling and the plane in which the cable plane construction line lies as the cable plane, and obtaining the acceleration of the predetermined sling along the cable plane towards the adjacent sling as the cable plane acceleration, and obtaining the acceleration of the predetermined sling along the normal of the cable plane as the cable plane normal acceleration.

[0069] Specifically, the axis of the bridge predetermined sling and the sling adjacent thereto are both located in the cable plane, and in this embodiment, the measurement points of the cable plane normal acceleration and the cable plane acceleration are the same point.

[0070] Step S4: obtaining the sling along-flow displacement amount of the predetermined sling along the environmental wind direction and the sling cross-flow displacement amount of the predetermined sling perpendicular to the sling along-flow displacement amount based on the environmental wind direction, the cable plane acceleration and the cable plane normal acceleration.

[0071] Step S4 includes the following sub-steps:

[0072] Step S4-1: obtaining the combined vector acceleration by vector combination of the cable plane acceleration and the cable plane normal acceleration.

[0073] Step S4-2: decomposing the combined vector acceleration along the environmental wind direction and the vertical direction of the environmental wind direction to obtain the sling along-flow acceleration and the sling cross-flow acceleration.

[0074] Step S4-3: obtaining the sling along-flow displacement amount and the sling cross-flow displacement amount by time-frequency transformation of the time-domain curve of the sling along-flow acceleration and the time-domain curve of the sling cross-flow acceleration.

[0075] Specifically, first, the time-domain curve continuously formed by the time-domain signal of the combined vector acceleration is obtained, and is converted into a frequency-domain signal by fast Fourier transform, then, the frequency-domain signal of the combined vector acceleration is multiplied by 1 / jω in the frequency domain to obtain the corresponding frequency-domain signal of the combined vector velocity, then, the frequency-domain signal of the combined vector velocity is multiplied by -1 / ω 2 the corresponding frequency-domain signal of the combined vector displacement is obtained, the time-domain signal of the combined vector displacement continuously formed by the time-domain signal of the combined vector displacement is used, and finally, the combined vector displacement is vector-decomposed along the along-wind direction and the cross-wind direction to obtain the corresponding sling along-flow displacement amount and the sling cross-flow displacement amount, respectively, in this embodiment, the environmental wind direction and the wind speed are obtained by the wind direction and speed sensor pre-installed on the bridge, and the wind direction and speed sensor is a device commonly used and easily purchased in the market.

[0076] Step S5: obtaining the sling along-flow vortex vibration frequency based on the sling along-flow displacement amount, and obtaining the sling cross-flow vortex vibration frequency based on the sling cross-flow displacement amount.

[0077] The in-line vortex vibration frequency of the sling is a peak value of a frequency domain curve of in-line displacement of the sling, and the cross-flow vortex vibration frequency of the sling is a peak value of a frequency domain curve of cross-flow displacement of the sling.

[0078] Step S6: Obtain a multi-order mode function of the predetermined sling and a plurality of mode frequencies corresponding to the multi-order mode function, and obtain in-line vortex vibration mode functions and cross-flow vortex vibration mode functions of the predetermined sling according to fitting results of the in-line vortex vibration frequency, the cross-flow vortex vibration frequency and the plurality of mode frequency curves.

[0079] Step S6 includes the following sub-steps:

[0080] Step S6-1: Establish a sling finite element model according to a mass matrix and a stiffness matrix of the predetermined sling.

[0081] Step S6-2: Obtain the multi-order mode function and the plurality of mode frequencies based on the sling finite element model.

[0082] Step S6-3: Fit the curve of the in-line wind direction vortex vibration frequency with the plurality of mode frequency curves respectively, and take the mode function corresponding to the mode frequency with the highest fitting degree as the in-line wind direction vortex vibration mode function; fit the cross-flow wind direction vortex vibration frequency with the plurality of mode frequencies respectively, and take the mode function corresponding to the mode frequency with the highest fitting degree as the cross-flow wind direction vortex vibration mode function.

[0083] Step S7: Establish an in-line vortex vibration motion equation and a cross-flow vortex vibration motion equation of the predetermined sling respectively.

[0084] Step S7 includes the following sub-steps:

[0085] Step S7-1: Establish the in-line vortex vibration motion equation:

[0086]

[0087] m is the mass per meter of the predetermined sling, y1 represents the in-line displacement of the sling, ε represents the sling damping ratio of the predetermined sling, ω1 is the in-line vortex vibration frequency of the sling, is the in-line vortex excitation force coefficient of the predetermined sling, D is the structural characteristic width, U is the wind speed, and ρ is the air density. Specifically, the sling damping ratio ε is obtained through an artificial excitation test.

[0088] Step S7-2: Dimensionless the equation in step S7-1:

[0089]

[0090] s = Ut / D, η1 = y1 / D, K0 = ω1D / U,

[0091] Step S7-3: Establish the cross-flow vortex vibration motion equation:

[0092]

[0093] y2 represents the transverse flow direction displacement of the sling, and ω2 is the transverse flow direction vortex-induced vibration frequency of the sling, is the transverse flow direction vortex-induced force coefficient of the predetermined sling.

[0094] Step S7-4: Dimensionless the equation in step S7-3:

[0095]

[0096] η2=y2 / D,K0=ω2D / U.

[0097] Step S8: Obtain the in-line vortex-induced force parameters of the predetermined sling based on the in-line vortex-induced vibration mode function and the in-line vortex-induced motion equation of the sling, and obtain the transverse flow direction vortex-induced force parameters of the predetermined sling based on the transverse flow direction vortex-induced vibration mode function and the transverse flow direction vortex-induced motion equation of the sling.

[0098] Step S8 includes the following sub-steps:

[0099] Step S8-1: Obtain the vortex-induced resonance response relationship η(x, s) based on the vortex-induced vibration mode function:

[0100] η(x, s)=Φ(x)v(s)

[0101] Φ(x) is the vortex-induced vibration mode function, and v(s) is the modal coordinate.

[0102] Step S8-2: Combine the vortex-induced resonance response relationship with the in-line vortex-induced motion equation and the transverse flow direction vortex-induced motion equation respectively to obtain:

[0103]

[0104]

[0105] is the in-line generalized mass of the predetermined sling, Φ1(x) is the in-line vortex-induced vibration mode function, and v1(s) is the in-line modal coordinate, is the transverse flow direction generalized mass of the predetermined sling, Φ2(x) is the transverse flow direction vortex-induced vibration mode function, and v2(s) is the transverse flow direction modal coordinate, and L is the length of the predetermined sling, is the initial phase of the transverse flow direction vortex-induced force parameters, is the initial phase of the in-line vortex-induced force parameters,

[0106] Step S8-3: Calculate the transverse flow direction vortex-induced force parameters and the in-line vortex-induced force parameters by least square fitting

[0107] As Figures 2 to 4As shown, the measuring device 100 for implementing the above-mentioned method S100 for obtaining the vortex-induced force parameters of the predetermined suspension cables of the bridge includes a fixing part 10, a measuring part 20 and a control part (not shown in the drawings).

[0108] The fixing portion 10 is detachably mounted on a predetermined sling, such as Figure 5 As shown, the fixing portion 10 includes an arc-shaped clamping sleeve 11 .

[0109] The number of the arc clamps 11 is a pair, and the pair of arc clamps clamps and fixes the predetermined sling from both sides of the predetermined sling.

[0110] The arc clamp 11 is in the shape of an arc hoop with an arc of no more than 180°, and has a movable guide rail 111 and a connecting ear 112. In this embodiment, the arc clamp 11 is in the shape of a semicircular hoop, and a cylindrical channel for a predetermined sling to pass through is formed between a pair of arc clamps 11.

[0111] The plane where the movable guide rail 111 is located is perpendicular to the axis of the predetermined sling, and the movable guide rail 111 extends along the same curvature path as the arc barrel 11, that is, the cylindrical surface where the outer surface of the movable guide rail 111 is located is coaxial with the arc barrel 11. In this embodiment, the movable guide rail 111 is located in the middle of a circular arc barrel 11.

[0112] Specifically, the connecting ears 112 are used to connect a pair of arc clamps 11 and enable the arc clamps 11 to be tightly fixed on a predetermined sling.

[0113] The measuring unit 20 is disposed on the fixing unit 10 and includes a movable fixing member 21 , a supporting base 22 , a laser emitter 23 and an acceleration sensor 24 .

[0114] like Figure 6 As shown, the movable fixing member 21 has a movable groove 211 and a stop screw 212 . In this embodiment, the movable fixing member 21 is an arc-shaped bar with the same arc as that of the movable guide rail 111 .

[0115] The movable groove 211 cooperates with the movable guide rail 111 and is movably arranged along the extension path of the movable guide rail 111. The top stop screw 212 is passed through the movable fixing part 21 and extends into the movable groove 211. The top stop screw 212 is used to tighten and fix the movable fixing part 21 on the movable guide rail 111. Specifically, the top stop screw 212 extends vertically into the movable groove 211 from the side wall of the movable groove 211.

[0116] The bearing base 22 is fixed on the movable fixing member 21. Specifically, the bearing base 22 is arranged on the opposite side of the movable groove 211. In this embodiment, the bearing base 22 has a bearing space sunk along the extension direction of the arc clamping cylinder 11 (not shown in the drawings).

[0117] The laser emitter 23 and the acceleration sensor 24 are both fixedly mounted in the bearing space of the bearing base 22 , and are both located near the predetermined sling.

[0118] The laser emitter 23 is used to emit a constructed laser beam such as the method S100 for obtaining the vortex-induced force parameters of the predetermined bridge cable. The emission direction of the laser emitter 23 is perpendicular to the axis of the predetermined bridge cable. The acceleration sensor 24 is used to obtain the cable plane acceleration and the cable plane normal acceleration such as the method S100 for obtaining the vortex-induced force parameters of the predetermined bridge cable. In this embodiment, the acceleration sensor 24 is located on the straight line where the emission direction of the laser emitter 23 is located.

[0119] The control unit is connected to the acceleration sensor signal. Specifically, the control unit is also connected to the wind direction and wind speed sensor signals preset on the bridge.

[0120] The following describes the implementation of the device for measuring vortex excitation force parameters in conjunction with the embodiments:

[0121] like Figure 7 As shown, the vortex-excitation force parameter measuring device 100 is fixed to the predetermined sling S through the fixing part 10, and the laser emitter 23 emits a structural laser beam having a laser beam optical path L1 from the supporting base 22. The direction of the laser beam optical path L1 is adjusted by moving the movable fixing part 21 on the movable guide rail 111 relative to the fixing part 10. When the laser beam optical path L1 is irradiated to the surface of the adjacent sling S1 adjacent to the predetermined sling S, that is, the light spot can be observed, the structural laser beam and the axis of the predetermined sling S constitute a cable plane, and the axis of the adjacent sling S1 is also located in the cable plane. At this time, the downstream vortex-excitation force parameters and the cross-stream vortex-excitation force parameters of the predetermined sling of the bridge can be obtained through the method S100 for obtaining the vortex-excitation force parameters of the predetermined sling.

[0122] The above-mentioned embodiments are preferred cases of the present invention and are not intended to limit the scope of protection of the present invention. Various deformations or modifications that can be made by ordinary technicians in this field without creative work within the scope of the attached claims are still within the scope of protection of this patent.

Claims

1. A method for obtaining vortex-induced force parameters of a predetermined suspension cable of a bridge, wherein the bridge has a plurality of parallel suspension cables including the predetermined suspension cable, characterized in that: The following steps are involved: Step S1: setting a cable plane construction line perpendicularly intersecting the axis of the predetermined sling; Step S2: rotating the cable plane construction line with the axis of the predetermined sling as the rotation axis so that the cable plane construction line passes through the axis of the sling adjacent to the predetermined sling, Step S3: taking the plane where the axis of the predetermined sling and the cable plane construction line are located as the cable plane, obtaining the acceleration of the predetermined sling along the cable plane toward the adjacent sling as the cable plane acceleration, and obtaining the acceleration of the predetermined sling along the normal direction of the cable plane as the cable plane normal acceleration; Step S4: obtaining a downstream displacement of the predetermined sling along the ambient wind direction and a transverse displacement of the predetermined sling perpendicular to the downstream displacement of the predetermined sling based on the ambient wind direction, the sling plane acceleration, and the sling plane normal acceleration; Step S5: obtaining the vortex vibration frequency of the sling in the downstream direction based on the displacement of the sling in the downstream direction, and obtaining the vortex vibration frequency of the sling in the transverse direction based on the displacement of the sling in the transverse direction; Step S6: obtaining a multi-order vibration mode function of the predetermined sling and a plurality of vibration mode frequencies corresponding to the multi-order vibration mode function, and obtaining a downstream vortex vibration vibration mode function and a transverse vortex vibration vibration mode function of the predetermined sling according to fitting results of the downstream vortex vibration frequency of the sling, the transverse vortex vibration frequency of the sling, and the plurality of vibration mode frequency curves; Step S7: establishing a vortex vibration motion equation in the downstream direction and a vortex vibration motion equation in the transverse direction of the predetermined sling respectively; Step S8: Based on the downstream vortex vibration vibration mode function and the downstream vortex vibration motion equation of the sling, the downstream vortex excitation force parameters of the predetermined sling are obtained; based on the cross-stream vortex vibration vibration mode function and the cross-stream vortex vibration motion equation of the sling, the cross-stream vortex excitation force parameters of the predetermined sling are obtained.

2. The method for obtaining vortex-induced force parameters of a predetermined bridge suspension cable according to claim 1, characterized in that: in, In step S1 , a construction laser beam is set, the optical path of the construction laser beam being the cable plane construction line.

3. The method for obtaining vortex-induced force parameters of a predetermined bridge suspension cable according to claim 1, characterized in that: in, Step S4 includes the following sub-steps: Step S4-1: performing vector synthesis of the cable plane acceleration and the cable plane normal acceleration to obtain a synthetic vector acceleration; Step S4-2: Decomposing the synthetic vector acceleration along the ambient wind direction and the direction perpendicular to the ambient wind direction to obtain the downstream acceleration of the sling and the cross-stream acceleration of the sling; Step S4-3: The time domain curve of the downstream acceleration of the cable and the time domain curve of the cross-stream acceleration of the cable are subjected to time-frequency transformation to obtain the downstream displacement of the cable and the cross-stream displacement of the cable.

4. The method for obtaining vortex-induced force parameters of a predetermined bridge suspension cable according to claim 1, characterized in that: in, In step S5, the vortex vibration frequency of the sling in the downstream direction is the peak value of the frequency domain curve of the sling in the downstream direction; the vortex vibration frequency of the sling in the transverse direction is the peak value of the frequency domain curve of the sling in the transverse direction.

5. The method for obtaining vortex-induced force parameters of a predetermined bridge suspension cable according to claim 1, characterized in that: in, Step S6 includes the following sub-steps: Step S6-1: establishing a sling finite element model according to the mass matrix and stiffness matrix of the predetermined sling; Step S6-2: obtaining the multi-order mode shape function and the multiple mode shape frequencies based on the sling finite element model; Step S6-3: Fit the curve of the vortex vibration frequency of the cable in the downwind direction with the curves of the multiple vibration mode frequencies respectively, and use the vibration mode function corresponding to the vibration mode frequency with the highest fitting degree as the downwind vortex vibration vibration mode function; fit the vortex vibration frequency of the cable in the crosswind direction with the multiple vibration mode frequencies respectively, and use the vibration mode function corresponding to the vibration mode frequency with the highest fitting degree as the crosswind vortex vibration vibration mode function.

6. The method for obtaining vortex-induced force parameters of a predetermined bridge suspension cable according to claim 1, characterized in that: in, Step S7 includes the following sub-steps: Step S7-1: Establish the downstream vortex motion equation: m is the mass per meter of the predetermined sling, y1 represents the displacement of the sling in the downstream direction, ε represents the sling damping ratio of the predetermined sling, ω1 is the vortex vibration frequency of the sling in the downstream direction, is the downstream vortex excitation coefficient of the predetermined sling, D is the structural characteristic width, U is the wind speed, ρ is the air density, Step S7-2: Non-dimensionalize the equation in step S7-1: s=Ut / D, η1=y1 / D, K0=ω1D / U, Step S7-3: Establish the transverse vortex motion equation: y2 represents the transverse displacement of the sling, ω2 is the transverse vortex vibration frequency of the sling, is the cross-stream vortex excitation coefficient of the predetermined sling, Step S7-4: Non-dimensionalize the equation in step S7-3: η2=y2 / D,K0=ω2D / U。 7. The method for obtaining vortex-induced force parameters of a predetermined bridge suspension cable according to claim 6, characterized in that: in, Step S8 includes the following sub-steps: Step S8-1: Obtain the vortex-induced resonance response relationship η(x, s) based on the vortex vibration mode function: η(x, s)=Φ(x)v(s) Φ(x) is the vortex vibration mode function, v(s) is the modal coordinate; Step S8-2: The vortex-induced resonance response relationship is combined with the downstream vortex vibration motion equation and the cross-flow vortex vibration motion equation to obtain: is the downstream generalized mass of the predetermined sling, Φ1(x) is the downstream vortex vibration mode function, v1(s) is the downstream modal coordinate, is the transverse generalized mass of the predetermined sling, Φ2(x) is the transverse vortex vibration mode function, v2(s) is the transverse modal coordinate, L is the length of the predetermined sling, is the initial phase of the cross-stream vortex excitation parameter, is the initial phase of the downstream vortex excitation parameter, Step S8-3: Calculate by least squares fitting 8. A device for measuring vortex-induced force parameters for implementing the method for obtaining vortex-induced force parameters of a predetermined bridge suspension cable according to any one of claims 1 to 7, characterized in that: include: a fixing portion detachably provided on the predetermined sling according to any one of claims 1 to 7; The measuring unit is provided on the fixing unit and includes a laser emitter and an acceleration sensor both located near the predetermined sling. The laser emitter is used to emit the construction laser beam according to claim 2, the emission direction of the laser emitter is perpendicular to the axis of the predetermined sling, and the acceleration sensor is used to obtain the cable plane acceleration and the cable plane normal acceleration according to any one of claims 1 to 7; as well as The control unit is connected to the acceleration sensor signal.

9. The device for measuring vortex force parameters according to claim 8, characterized in that: in, The fixing portion includes a pair of detachable arc clamps, and the pair of arc clamps tightly hold the predetermined sling from both sides of the predetermined sling.

10. The device for measuring vortex force parameters according to claim 9, characterized in that: in, The arc cartridge has an outwardly convex movable guide rail, the plane where the movable guide rail is located is perpendicular to the axis of the predetermined sling, and the movable guide rail extends along the same curvature path as the arc cartridge. The measuring part further includes a movable fixing part and a bearing base fixed on the movable fixing part. The movable fixing member has a movable groove and a stop screw. The movable groove cooperates with the movable guide rail and is movably arranged along the extension path of the movable guide rail. The stop screw is provided on the movable fixing member and extends into the movable groove. The stop screw is used to tighten the movable fixing member against the movable guide rail. The laser emitter and the acceleration sensor are both fixed on the bearing base.

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