Large deformation extensometer

Abstract

The invention provides a large deformation extensometer, comprising a sensor, a regulating bar with a hook, a fixed bar, a scale distance limiting plate and a pair of an upper knife edge group and a lower knife edge group which are eudipleural and arranged at the upper part of the regulating bar and at the lower part of the sensor respectively; the extensometer is characterized in that the sensor which is arranged at the lower part of the fixed bar and articulated with the hook at the lower part of the regulating bar is a draw out type displacement sensor; the draw out type displacement sensor comprises a box body, a steel wire rope and a coil spring type contracting mechanism A and an encoder which are arranged in the box body; the coil spring type contracting mechanism comprises a clockwork spring shaft one end of which is fixedly connected with the box body, a spring plate capable of circuition arranged at an axis body and a disk clockwork spring one end of which is fixed on a locating shaft and the other end of which is fixed in the inside cavity of the spring plate; one end of the steel wire rope is fixed on the spring plate and led out after being sheathed and wound by a winding shaft which is in swing connection with the encoder; the other led out end thereof is directly connected with the hook and forms a large deformation extensometer automatic contracting mechanism with the hook at the lower part of the regulating bar by the hook.

Description

technical field [0001] The invention relates to a sensing device for detecting deformation, in particular to a large deformation extensometer, which is suitable for the large deformation extensometer with arbitrarily determined gauge length within the range of 400-1000mm. Background technique [0002] The national standard GB / T5224-2003 stipulates the classification, size and test methods of steel strands for prestressed concrete. The national standard stipulates that when measuring the elongation of steel strands, the gauge length of 1×2 and 1×3 structural steel strands is not less than 400mm; the gauge length of 1×7 structural steel strands is not less than 500mm. [0003] At present, one of the large deformation extensometers in China is a strain extensometer with a gauge length of 200mm, and an extension rod is added at the measuring end to replace the extensometer with a large gauge length. The maximum gauge length is only 400mm. If it is longer, it will become unstabl...

AI Technical Summary

Problems solved by technology

This type of extensometer is heavy, which is not conducive to operation; the gauge length range is strictly limited, and the deformation measurement range is small

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