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Tangential single bolt relaxation measuring device and method based on modal parameter characterization

A modal parameter and relaxation measurement technology, which is used in measurement devices, testing of mechanical components, and testing of machine/structural components, etc. It can solve problems such as the unclear relationship between relaxation and vibration displacement, and the inability to measure changes in bolt modal parameters. , to achieve the effect of simple structure and guaranteed accuracy

Active Publication Date: 2017-11-28
BEIJING UNIV OF TECH
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  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The problem to be solved by the present invention is to solve the problem that the modal parameter change in the bolt relaxation process cannot be measured and the relationship between relaxation and vibration displacement is not clear in the existing device

Method used

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  • Tangential single bolt relaxation measuring device and method based on modal parameter characterization
  • Tangential single bolt relaxation measuring device and method based on modal parameter characterization
  • Tangential single bolt relaxation measuring device and method based on modal parameter characterization

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Embodiment Construction

[0025] The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

[0026] Step 1: Measure the modal parameters of the entire connected specimen through the LMS vibration tester and establish a corresponding database, including parameters such as natural frequency, damping ratio, and modal shape as initial reference values ​​for modal characteristics. Start the tensile testing machine 1, pressurize and preheat; the pressure sensor 3, the digital signal amplifier 8, the data acquisition card 9 and the computer 10 are connected in sequence, and the initial value is set to zero by software; the pressure sensor 3 is worn on the screw rod 4 Up; Connect screw 4, pressure sensor 3, upper connector 2, lower connector 5, and nut 6 in series in sequence; control the digital display torque wrench to control the pre-tightening force of the bolt, set the initial value of the pre-tightening force of the bolt, and the computer will d...

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Abstract

The invention discloses a tangential single bolt relaxation measuring device and method based on modal parameter characterization, belonging to the field of mechanical manufacturing and structural mechanics. The measuring device includes a bolt tensile test machine, a tangential specimen, a bolt data acquisition system, and an LMS vibration test system. The method includes the following steps: obtaining a relaxation law curve of a bolt through the tensile test machine, the tangential specimen and the bolt data acquisition system; getting feature stages of bolt relaxation; using the LMS vibration test system to measure the modal parameters of different relaxation stages; and finally, using the modal parameters to characterize the relaxation characteristics of the bolt. According to the device and the method, the modal parameters are acquired by changing the vibration frequency to different values and loading loads to characterize the bolt relaxation characteristics under the influence of various parameters. The invention relates to an improved tangential connection specimen, which ensures that the connection characteristics and relaxation of bolts can be measured, and improves the accuracy of bolt relaxation measurement. The invention further presents a method of characterizing the relaxation of tangent single bolts with modal parameters.

Description

technical field [0001] The invention relates to a tangential single bolt relaxation measurement device and method based on modal parameter characterization, belonging to the fields of mechanical manufacturing and structural mechanics. Background technique [0002] In practical engineering, the mechanical connection of various structural elements assembled by fasteners such as bolts is one of the most commonly used connection forms. Under the mechanical environment such as shock and vibration, the bolted connection often slips, separates or even loosens, which leads to the loosening of the bolts. Bolt loosening is one of the main mechanisms leading to fatigue failure of fastener connections and loss of structural integrity. The modal parameters are functions of the mass, damping, and stiffness of the structure. Modal parameters can characterize the fastening characteristics of connectors such as structural member stiffness, vibration characteristics and damping characterist...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01M13/00G01M7/02G01N3/02G01N3/08
CPCG01M7/025G01M7/027G01M13/00G01N3/02G01N3/08
Inventor 蔡力钢徐文祥刘志峰李迎刘强张明洋
Owner BEIJING UNIV OF TECH
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