Drop hammer structural design based on stress concentration principle and test method thereof

A technology of stress concentration and structural design, applied in the direction of applying repetitive force/pulse force to test the strength of materials, measuring devices, instruments, etc., which can solve the problems of high price and poor anti-interference performance.

Inactive Publication Date: 2016-05-04
ZHONGBEI UNIV
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  • Abstract
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  • Claims
  • Application Information

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Problems solved by technology

At present, the drop weight testing machine in the laboratory uses a piezoelectric sensor to test the impact force, which is relatively expensive and has poor anti-interference performance.

Method used

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  • Drop hammer structural design based on stress concentration principle and test method thereof
  • Drop hammer structural design based on stress concentration principle and test method thereof
  • Drop hammer structural design based on stress concentration principle and test method thereof

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Embodiment Construction

[0036] In order to make the purpose, content, and advantages of the present invention clearer, the specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0037] The invention adopts the principle of stress concentration to design the drop hammer structure, and adopts the double bridge circuit of the Wheatstone bridge to measure the concentrated impact force of the beam. The test method is applied to the test of the impact force of the concentrated loading of the large-scale reinforced concrete beam. The length, width and height of the beam are 1200×120×120 (mm) and specifically include the following steps:

[0038] Step S1: In order to form plane stress, the drop hammer is designed in the shape of a thin plate, and the thickness and size of the drop hammer are determined according to the specific requirements of the experiment. According to the bearing capacity of the r...

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Abstract

The invention belongs to the technical field of impact tests, and in particular relates to drop hammer structural design based on a stress concentration principle and a method adopting a Wheatstone full bridge circuit for testing impact force. Due to the fact that the elastic strain of a drop hammer is relatively small, in order to improve the test sensitivity, and improve the capacity of resisting disturbance, the drop hammer is made into a thin plate structure, holes are drilled in the middle of the plate, and the strain around the hole is improved through the stress concentration principle. The Wheatstone full bridge mode connecting circuit is adopted, so as to obtain the whole average strain of the drop hammer, to improve a temperature error and a non-linear error. Static load is adopted for calibrating the drop hammer, and a result shows that the output voltage has a linear relation with load. The method is different from a common drop hammer structure and test method, the drop hammer adopts the thin plate structure with two circular holes, each hole is internally and uniformly provided with 4 resistance strain gages, the eight resistance strain gages are connected to be the Wheatstone full bridge circuit, the output voltage is measured, and tested impact force is obtained according to calibration.

Description

technical field [0001] The invention belongs to the technical field of impact testing, in particular to a testing method for designing a drop hammer structure and its impact force by adopting the principle of stress concentration. Background technique [0002] The testing of the dynamic mechanical properties of materials is often carried out by dropping the hammer. In order to improve the measurement accuracy of the instantaneous impact force of the falling hammer and reduce the test cost, it is necessary to design the structure of the dropping hammer and its testing method according to the structure of the specimen and the loading method. At present, the drop weight testing machine in the laboratory uses a piezoelectric sensor to test the impact force, which is relatively expensive and has poor anti-interference performance. For some large-scale structural impact experiments that need to be carried out in the field, it is very necessary to make a self-made economical and pr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/303G01N3/34G01N3/06
CPCG01N3/066G01N3/303G01N3/34
Inventor 展婷变裴畅贵吕淑芳裴均晔陈智刚王坚茹严志宏
Owner ZHONGBEI UNIV
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