Method for characterizing fatigue damage state of prestressed concrete beam and testing device

A technology for concrete beams and fatigue damage, which is used in measuring devices, using repetitive force/pulse force to test material strength, and using sonic/ultrasonic/infrasonic waves to analyze solids, etc. It is difficult to reveal the development process of fatigue damage and fatigue failure mechanism of prestressed concrete beams, so as to achieve the effect of simple structure and convenient testing.

Pending Publication Date: 2019-02-22
CENT SOUTH UNIV
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Problems solved by technology

The entry point of these methods is relatively single, and cannot reflect the mechanical characteristics of the structure under the action of fatigue dynamic load, and it is difficult to reveal the development process of fatigue damage and the fatigue damage mechanism of prestressed concrete beams. A New Approach to the Fatigue Problem of Concrete Beams

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  • Method for characterizing fatigue damage state of prestressed concrete beam and testing device
  • Method for characterizing fatigue damage state of prestressed concrete beam and testing device
  • Method for characterizing fatigue damage state of prestressed concrete beam and testing device

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Embodiment

[0063] The prestressed concrete simply supported T-beam of a standard railway bridge with a height of 32 m is selected as the prototype beam. According to the similarity theory, a 1:6 scale model of the prototype beam is made as the prestressed concrete beam 3 to be tested. The design parameters are shown in Table 1 below. In this embodiment, 3 model beams were prepared, one of which (number No. 1) was used for the static load test to determine the required static limit load P of the fatigue test. u , measured P u =265kN; the other two (No.2, No.3) are used for fatigue test.

[0064] Table 1 model beam design parameter

[0065]

[0066] The concrete mix ratio is cement: water: stone: sand: water reducer = 460: 118: 1092: 735: 4.2, the concrete test blocks are reserved when pouring each test beam, and the mechanical performance test is carried out at the same time as the model beam test. The mechanical properties are shown in Table 2 below:

[0067] Table 2 Measured mec...

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Abstract

The invention discloses a method for characterizing the a fatigue damage state of a prestressed concrete beam. The method comprises the following steps that initial dynamic parameters of the prestressed concrete beam are determined, and a first-time static load test is conducted; in the fatigue loading process, a static load test and power testing are conducted on the prestressed concrete beam; vibration modal parameters of the prestressed concrete beam are analyzed; and the fatigue damage state of the prestressed concrete beam is evaluated. The invention further discloses a measuring device for realizing the method. According to the method, power testing is carried out in the structural fatigue testing process of the prestressed concrete beam structural fatigue testing process, the fatigue damage position and the damage degree of the prestressed concrete beam are analyzed based on the vibration modal parameters, thus the fatigue damage state of the prestressed concrete beam is characterized based on the modal parameters, and a new idea is provided for study and testing of fatigue performance of the prestressed concrete beam.

Description

technical field [0001] The invention belongs to the technical field of fatigue damage testing of engineering structures, and in particular relates to a characterization method and testing device for the fatigue damage state of prestressed concrete beams. Background technique [0002] Prestressed concrete beams are widely used in civil and large-span engineering structures such as highway and railway bridges. This type of prestressed concrete beam will bear the repeated action of vehicle fatigue load for a long time within the design service life. Fatigue load will cause the occurrence and development of structural fatigue damage, and the accumulation of damage will affect the normal performance of the structure and even endanger the safety of the structure. Therefore, the fatigue performance of prestressed concrete beams has attracted the attention of many scholars and engineers at home and abroad. [0003] In the traditional prestressed concrete beam fatigue performance t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/32G01N29/04
CPCG01N3/32G01N29/045G01N2203/0005G01N2203/0073
Inventor 卫军杜永潇刘晓春林全富杨斌财梁曼舒刘康吴志强董荣珍陈山亭
Owner CENT SOUTH UNIV
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