CN-122016227-A - Buffeting load multipoint synchronous measurement device and method for large-span arch bridge wind tunnel test

CN122016227ACN 122016227 ACN122016227 ACN 122016227ACN-122016227-A

Abstract

The application discloses a buffeting load multipoint synchronous measurement device and method for a large-span arch bridge wind tunnel test, wherein the device comprises a base, a wind direction angle adjusting mechanism, an arch bridge truss model, a model supporting system and a multichannel synchronous data acquisition system; the arch bridge truss model comprises at least two test sections embedded with six-component balances, the six-component balances are located in the geometric centers of the sections and are fixedly connected with the main framework through rigid force transmission structures, gaps are arranged between adjacent sections, a wind direction angle adjusting mechanism is used for realizing rotation around a vertical shaft, a model supporting system is matched with the wind attack angle adjusting mechanism through supporting columns, the whole pitching of the arch bridge truss model is realized to adjust the wind attack angle of the arch bridge truss model, and a multichannel synchronous data acquisition system synchronously acquires time-course signals of three-dimensional aerodynamic forces born by each test section. The application can realize independent adjustment of double degrees of freedom, multipoint synchronous force measurement and load field reconstruction, is applicable to arch ribs with different curvatures, and can obviously improve the buffeting load identification precision of the large-span arch bridge.

Inventors

WU BO
ZHANG JIAN
SU LIANG
YU ZIMING
XIN JINGZHOU
ZHOU JIANTING
ZHANG HONG
LI SHUANGJIANG
LI JUNLIN
WU YULIN
Han Dongshan

Assignees

重庆交通大学
重庆市公路事务中心

Dates

Publication Date: 20260512
Application Date: 20260310

Claims (10)

1. A buffeting load multipoint synchronous measuring device for a large span arch bridge wind tunnel test, the device comprising: A base; the wind direction angle adjusting mechanism is fixedly connected below the base and is used for driving the base to rotate around a vertical shaft so as to set a wind direction angle; The arch bridge truss model comprises at least two test sections, wherein each test section is internally provided with a force measuring unit, each force measuring unit comprises a six-component balance and a rigid force transmission structure, the six-component balance is fixedly connected with a main force bearing framework of the corresponding test section through the rigid force transmission structure, the six-component balance is completely embedded in the test section and is positioned in the geometric center of the test section, and gaps are arranged between adjacent sections of the arch bridge truss model to realize mechanical decoupling; The model supporting system is arranged on the base and comprises a supporting upright post arranged on the base and a wind attack angle adjusting mechanism arranged on the supporting upright post, wherein the wind attack angle adjusting mechanism is connected with the arch bridge truss model and is used for adjusting the wind attack angle of the arch bridge truss model; The multichannel synchronous data acquisition system is electrically connected with the six-component balances of all the force measuring units and is used for synchronously acquiring time-course signals of three-dimensional aerodynamic forces born by each test section.
2. The buffeting load multipoint synchronous measuring device for the large-span arch bridge wind tunnel test according to claim 1, wherein the base is a circular base, the wind direction angle adjusting mechanism is a high-precision turntable, and the circular base is coaxially fixed on the high-precision turntable.
3. The buffeting load multipoint synchronous measuring device for the large span arch bridge wind tunnel test according to claim 1, wherein, The four supporting columns are divided into two groups, and the two groups of supporting columns are symmetrically arranged on the base left and right; The wind attack angle adjusting mechanism comprises three transverse struts, three pulleys, a transmission chain and a rigid connecting rod, wherein, One group of the support upright posts are provided with one transverse strut, and the other group of the support upright posts are provided with two transverse struts at intervals in parallel along the axial direction of the support upright posts; Each transverse strut is rotatably provided with one pulley, the transmission chain is wound on two pulleys on one side provided with two transverse struts, and the pulley on one side provided with only one transverse strut is coaxially arranged with the upper pulley on one side provided with two transverse struts; The rigid connecting rod spans between the two groups of support columns, one end of the rigid connecting rod is fixedly connected with the pulley on one side provided with only one transverse strut, and the other end of the rigid connecting rod is fixedly connected with the upper pulley on one side provided with the two transverse struts so as to forcedly synchronize the rotation angles of the pulleys on the two groups of support columns; One end of the arch bridge truss model is fixedly connected with the end face of the pulley on one side of the transverse strut, the other end of the arch bridge truss model is fixedly connected with the end face of the pulley on the lower part of one side of the transverse strut, and the arch bridge truss model is driven to incline integrally through synchronous movement of the pulleys on the two groups of support upright posts so as to adjust the wind attack angle of the arch bridge truss model.
4. A buffeting load multipoint synchronous measuring device for a large span arch bridge wind tunnel test according to claim 3, wherein, The two ends of each transverse strut are respectively sleeved on the two supporting columns of the same group in a sliding way; each supporting upright post is provided with an external thread, and a limit nut is respectively arranged above and below the corresponding transverse supporting rod and is matched with the external thread to limit the axial position of the transverse supporting rod on the supporting upright post, so that the installation height of the pulley is adjusted.
5. A buffeting load multi-point synchronous measuring device for a large span arch bridge wind tunnel test as in claim 1, wherein the arch bridge truss model further comprises at least one compensating section connected to the base by an elongated dowel bar for transferring the load of the corresponding compensating section directly to the base to avoid the load from interfering with the force measuring signal via the test section transfer.
6. A buffeting load multi-point synchronous measuring device for large span arch bridge wind tunnel test as in claim 1, wherein each test section is connected to the model support system by a test section restraint to allow the adjacent sections to generate relatively small amplitude vibrations while transferring the necessary restraint.
7. A measurement method of a buffeting load multipoint synchronous measurement device for a large span arch bridge wind tunnel test according to any one of claims 1 to 6, comprising the steps of: S1, fixing the wind direction angle adjusting mechanism on a wind tunnel test section, fixedly mounting the base on the wind direction adjusting structure, driving the base to rotate through the wind direction angle adjusting mechanism, and setting a target wind direction angle; S2, installing and adjusting the model supporting system, and setting a target wind attack angle of the arch bridge truss model; s3, installing the arch bridge truss model, and completing mechanical butt joint of two ends of the arch bridge truss model and a wind attack angle adjusting mechanism; s4, starting the multichannel synchronous data acquisition system, performing wind tunnel test under the turbulent wind field condition, and synchronously recording lift time interval signals and resistance time interval signals of each test section, pitching moment time interval signals of each test section and incoming flow turbulent fluctuation wind speed time interval signals; S5, directly identifying a pneumatic admittance function through cross spectrum analysis based on the lift time interval signals and the incoming flow turbulence pulsation wind speed time interval signals, calculating a buffeting force spatial coherence function at a delta y interval based on the lift time interval signals of the two test sections, and constructing a three-dimensional buffeting load field along the span direction of the bridge based on aerodynamic time interval data of each test section.
8. The measurement method according to claim 7, wherein in step S5, the constructing a three-dimensional buffeting load field along the span direction of the bridge based on aerodynamic time course data of each test segment specifically includes: and (3) equivalent aerodynamic force measured by each test section to a distributed load acting on a strip with a unit length and a span length of zero, so as to construct a three-dimensional buffeting load field along the span direction of the bridge.
9. The method according to claim 7, wherein in step S5, the direct identification of the pneumatic admittance function by cross-spectrum analysis specifically comprises: And calculating the cross power spectral density between the lift time interval signal and the incoming flow turbulence pulsation wind speed time interval signal, and combining the self power spectral density of the lift time interval signal to obtain the modulus value and the phase characteristic of the aerodynamic admittance function.
10. The method of measuring according to claim 7, further comprising repeating steps S1 through S4 at different wind direction angles in combination with wind attack angles to build a buffeting load database covering Quan Gongkuang fields for supporting a fine wind resistant design of a large span arch bridge.

Description

Buffeting load multipoint synchronous measurement device and method for large-span arch bridge wind tunnel test Technical Field The application relates to the technical field of bridge wind engineering, in particular to a buffeting load multipoint synchronous measuring device and method for a large-span arch bridge wind tunnel test, which are suitable for accurately acquiring three-dimensional buffeting loads distributed along the span direction of an arch bridge structure in a turbulent wind field and directly identifying a pneumatic admittance function and spatial coherence characteristics. Background Large span arch bridges are becoming increasingly important for economy and aesthetic value as a key form of modern transportation infrastructure. However, as the span increases, the structure becomes more gentle and its sensitivity to wind loads increases significantly. Buffeting, a limited vibration induced by natural turbulence in the atmosphere, does not cause destructive divergence like flutter, but is the most common phenomenon of wind-induced vibration encountered by bridges during operation. The long-term buffeting response can cause structural fatigue, affect driving safety and comfort, and can finally restrict service life and performance of the bridge. Therefore, the accurate acquisition of buffeting load acting on the arch bridge structure is a fundamental premise for wind vibration response accurate prediction and structural safety and reliability evaluation. However, the prior art is mostly directed to force measurement research on a simple beam bridge section, and lacks a wind load measuring device special for a complex space structure of an arch bridge. The arch rib, the suspender and other members of the arch bridge are mutually coupled, and the pneumatic load distribution characteristics of the arch bridge are obviously different from those of the beam bridge. The traditional single balance force measurement only can obtain the whole aerodynamic force of the arch bridge truss model, and the aerodynamic loads born by different components such as the main beam, the arch rib and the like cannot be synchronously measured. Meanwhile, the aerodynamic admittance is a key aerodynamic parameter in bridge buffeting analysis and is used for describing the wind power correction effect of the structure on incoming flow turbulence. The accuracy directly determines the reliability of the buffeting response prediction. Currently, the main methods for identifying pneumatic admittance are indirect and direct. The indirect method is complex in theory and greatly influenced by structural dynamic characteristics by measuring vibration response back calculation aerodynamic force. The direct rule calculates by synchronously measuring wind load and wind speed time course, and the technical difficulty is high. The traditional experimental device is fixed in a wind tunnel, the wind direction angle and the wind attack angle of the arch bridge truss model are difficult to be quickly and accurately adjusted, the transformation of different arch axis lines cannot be simulated, and the experimental efficiency is low. Meanwhile, the supporting system of the traditional arch bridge truss model often introduces larger pneumatic interference or mechanical interference to influence the accuracy of the force measuring balance. Therefore, an integrated high-precision test system is urgently needed, and synchronous measurement of buffeting load and response of the arch bridge under flexible adjustment of multiple parameters can be realized. Disclosure of Invention The application provides a buffeting load multipoint synchronous measuring device and method for a large-span arch bridge wind tunnel test, which are used for solving the problems that the multipoint buffeting load cannot be synchronously measured, the wind attack angle and the wind direction angle are difficult to flexibly adjust, the interference of a supporting system is large and the like in the prior art. The application provides a buffeting load multipoint synchronous measuring device for a large-span arch bridge wind tunnel test. The first object of the present application is achieved by the following technical solutions: A buffeting load multipoint synchronous measurement device for a large span arch bridge wind tunnel test, the device comprising: A base; the wind direction angle adjusting mechanism is fixedly connected below the base and is used for driving the base to rotate around a vertical shaft so as to set a wind direction angle; The arch bridge truss model comprises at least two test sections, wherein each test section is internally provided with a force measuring unit, each force measuring unit comprises a six-component balance and a rigid force transmission structure, the six-component balance is fixedly connected with a main force bearing framework of the corresponding test section through the rigid force transmission structure, the six-component bal