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CN-122016206-A - Experimental device and method for simulating real form of crack of high-speed railway simply supported box girder

CN122016206ACN 122016206 ACN122016206 ACN 122016206ACN-122016206-A

Abstract

The invention discloses an experimental device and method for simulating the real form of a crack of a high-speed railway simply supported box girder, wherein the device comprises a high-speed railway simply supported box girder structure model, an initial prefabricated crack area is arranged on one side of the high-speed railway simply supported box girder structure model, and a crack monitoring system is arranged in the initial prefabricated crack area; the crack monitoring system comprises an acoustic emission sensor and a crack acquisition instrument, wherein the acoustic emission sensor and the crack acquisition instrument are respectively connected with a data acquisition instrument, and a crack secondary expansion excitation device is arranged on the outer side of the high-speed railway simply supported box girder structure model. The device induces secondary expansion of the crack by using a bridge structure model provided with an initial prefabricated crack and a secondary expansion excitation device until a crack tip is formed, so that crack evolution in an actual bridge structure is restored, and the expansion condition of the crack is monitored in real time by a crack monitoring system and data are accurately transmitted to data acquisition equipment. The device can capture key data in crack development, and ensure accuracy and reliability of experimental results.

Inventors

  • XIE HAIYANG
  • ZUO JUN
  • ZHU JINCAI
  • ZHANG MAOCHEN
  • LIU SAI
  • LI ZIRONG

Assignees

  • 西北水利水电工程有限责任公司

Dates

Publication Date
20260512
Application Date
20251230

Claims (8)

  1. 1. Experimental device for simulate real form of high-speed railway simply supported box girder crack, its characterized in that includes: The high-speed railway simply supported box girder structure model (2), wherein an initial prefabricated crack area (1) is arranged on one side of the high-speed railway simply supported box girder structure model (2), and a crack monitoring system (3) is arranged in the initial prefabricated crack area (1); the crack monitoring system (3) comprises an acoustic emission sensor (4) and a crack acquisition instrument (5), wherein the acoustic emission sensor (4) and the crack acquisition instrument (5) are respectively connected with the data acquisition instrument (6), and a crack secondary expansion excitation device (7) is arranged on the outer side of the high-speed railway simply supported box girder structural model (2).
  2. 2. The experimental device for simulating the real form of a crack of a high-speed railway simply supported box girder according to claim 1, wherein the experimental device is characterized in that: The crack secondary expansion excitation device (7) comprises a waveform generator (9), a power amplifier (10) and a vibration exciter (11), wherein the waveform generator (9) is connected with the power amplifier (10), the power amplifier (10) is connected with the vibration exciter (11), and a dynamic pressure sensor (12) is arranged at the bottom of the vibration exciter (11).
  3. 3. The experimental device for simulating the real form of a crack of a high-speed railway simply supported box girder according to claim 1, wherein the experimental device is characterized in that: And the initial prefabricated crack area (1) is subjected to secondary expansion to form a crack tip (8).
  4. 4. The experimental device for simulating the real form of a crack of a high-speed railway simply supported box girder according to claim 3, wherein the experimental device is characterized in that: The crack secondary expansion excitation device (7) is a high-speed railway train load loading system.
  5. 5. A method for simulating the real form of a crack of a high-speed railway simply supported girder bridge, which is characterized in that an experimental device for simulating the real form of the crack of the high-speed railway simply supported girder bridge according to any one of claims 1 to 4 is adopted, and the method comprises the following steps: s10, manufacturing a high-speed railway simply supported box girder structure model (2) by adopting a preset similarity ratio; s20, forming a crack combination device based on the high-speed railway simply supported box girder structure model (2); s30, tightly wrapping the crack combination device by using a preservative film, ensuring that the surface of the crack combination device is completely covered and the edge is sealed, placing the wrapped device in the bottom area of a cross-section web plate of a high-speed railway simply supported box girder structure model (2) according to the preset crack position requirement, fixing in place, and carrying out standard maintenance on the whole high-speed railway simply supported box girder structure model (2); s40, after the high-speed railway simply supported box girder structural model (2) is maintained, obtaining an initial prefabricated crack (1), and carrying out primary measurement on the initial prefabricated crack (1); s50, arranging a crack secondary expansion excitation device (7) at the outer side of the high-speed railway simply supported box girder structural model (2) to enable the initial prefabricated crack (1) to be secondarily expanded, and monitoring the secondary expansion state of the initial prefabricated crack (1); s60, removing a crack secondary expansion excitation device (7) when a crack monitoring system (3) collects a crack secondary expansion signal; s70, measuring the size and shape of the initial prefabricated crack (1) and the crack tip (8) by adopting a crack collector (5).
  6. 6. The method for simulating the real form of a crack in a high-speed railway simply supported box girder according to claim 5, wherein the step S20 comprises: s201, calculating the number of required crack prefabricating units (13) according to the size of the required prefabricating cracks in the high-speed railway simply supported box girder structural model (2); S202, combining the crack prefabrication units (13) transversely and vertically to form a crack combining device, wherein the crack combining device comprises vertically combined crack prefabrication units (14) and transversely combined crack prefabrication units (15).
  7. 7. The method for simulating the real form of a crack in a high-speed railway simply supported box girder according to claim 5, wherein the step S40 comprises: S401, taking out the crack combining device after the high-speed railway simply supported box girder structural model (2) is maintained, and obtaining an initial prefabricated crack (1); S402, performing preliminary measurement on the initial prefabricated crack (1) by adopting a crack acquisition instrument (5) to ensure that the size of the initial prefabricated crack (1) meets the requirements.
  8. 8. The method for simulating the real form of the crack of the high-speed railway simply supported box girder according to claim 5, which is characterized by comprising the following steps: The crack prefabrication unit (13) is a polyimide sheet.

Description

Experimental device and method for simulating real form of crack of high-speed railway simply supported box girder Technical Field The invention relates to the technical field of bridge engineering, in particular to an experimental device and method for simulating the real form of a crack of a high-speed railway simply supported box girder. Background During operation of a high-speed rail train, the bridge structure is generally subjected to vibration effects caused by passing of the train. While these vibrations typically do not result in significant damage to the bridge in the short term, the continual repeated action of dynamic loads may, in the long term, cause fatigue accumulation in the bridge structure. This fatigue effect gradually evolves into cracks at key locations of the bridge structure, such as the connection locations of a simply supported girder bridge or the areas where stresses are concentrated. These cracks may further propagate with the continued application of dynamic loads and ultimately pose a serious threat to the overall structural safety of the bridge. In order to deeply study and simulate the crack extension behavior of the bridge under the long-term operation condition of the high-speed rail train, an experimental device capable of simulating the crack morphology of the real bridge is generated. The experimental device can reproduce the formation and expansion process of the crack in the bridge structure by applying vibration load similar to that generated when a high-speed railway train passes through and matching with an accurate crack monitoring system. By means of the experimental device, the development of cracks of the high-speed railway simply supported girder bridge under the action of long-time dynamic load can be simulated, so that important experimental data support is provided for safety evaluation and maintenance strategy formulation of the bridge. However, the experimental device for simulating the real form of the crack of the high-speed railway simply supported box girder in the prior art does not consider the secondary expansion of the crack, so that the crack evolution in the actual bridge structure cannot be highly restored, and the accuracy and the reliability of an experimental result are lower. Disclosure of Invention The invention mainly aims to provide an experimental device and method for simulating the real form of a crack of a high-speed railway simply supported box girder, so as to solve the technical problems that in the prior art, the crack evolution in an actual bridge structure cannot be reduced to a high degree, and the accuracy and reliability of an experimental result are low. The experimental device for simulating the real form of the crack of the high-speed railway simply supported box girder comprises a high-speed railway simply supported box girder structure model, wherein an initial prefabricated crack area is arranged on one side of the high-speed railway simply supported box girder structure model, a crack monitoring system is arranged in the initial prefabricated crack area, the crack monitoring system comprises an acoustic emission sensor and a crack acquisition instrument, the acoustic emission sensor and the crack acquisition instrument are respectively connected with a data acquisition instrument, and a crack secondary expansion excitation device is arranged on the outer side of the high-speed railway simply supported box girder structure model. Optionally, the crack secondary expansion excitation device comprises a waveform generator, a power amplifier and a vibration exciter, wherein the waveform generator is connected with the power amplifier, the power amplifier is connected with the vibration exciter, and a dynamic pressure sensor is arranged at the bottom of the vibration exciter. Optionally, the initial pre-fabricated fracture zone is secondarily expanded to form a fracture tip. Optionally, the crack secondary expansion excitation device is a high-speed train load loading system. The application also provides a method for simulating the real form of the crack of the high-speed railway simply supported box girder, which is based on any experimental device for simulating the real form of the crack of the high-speed railway simply supported box girder, and comprises the following steps: S10, manufacturing a high-speed railway simply supported box girder structure model by adopting a preset similarity ratio; S20, forming a crack combination device based on a high-speed railway simply supported box girder structure model; S30, tightly wrapping the crack combination device by using a preservative film, ensuring that the surface of the crack combination device is completely covered and the edge is sealed, placing the wrapped device in the bottom area of a cross-section web plate of the high-speed railway simply supported box girder structure model according to the preset crack position requirement, fixing in place, and carrying out s