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

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...

AI Technical Summary

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.

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