Metal strain gauge with sparse interdigitated fingers in the axially distributed five-sensitive grid that can measure the axial deflection of the single-sided sheet

Abstract

A metal strain gauge with sparse interdigitated fingers in an axially distributed five-sensing grid that can measure the axial deflection of a single-sided sheet, including a base and five sensitive grids fixed on it; each sensitive grid includes a sensitive section and a transition section, The axes of each sensitive section are coplanar parallel straight lines; the direction along the axis in the plane is the axial direction, and the direction perpendicular to the axial direction is the transverse direction; there is no lateral deviation between the centers of the sensitive grids and there is a deviation in the axial direction; each sensitive grid is located according to the center position of the sensitive grid Sequence, from left to right along the axial direction is sparse A sensitive grid, sparse B sensitive grid, middle A sensitive grid, middle B sensitive grid and dense sensitive grid; the first two and the middle two sensitive grids are interdigitated Arrangement; the resistance change value of each sensitive grid under the same strain is 5:5:12:12:7. By time-division multiplexing the dense sensitive grid, the invention can almost simultaneously detect the axial first-order partial derivative of the strain at the distance from the right outer side of the dense sensitive grid center to the center equal to the distance from the center to the center of the sparse A and sparse B sensitive grids.

Description

technical field [0001] The invention relates to the field of sensors, in particular to a metal strain gauge. Background technique [0002] The working principle of the metal resistance strain gauge is the resistance strain effect, that is, when the metal wire is subjected to strain, its resistance changes correspondingly with the magnitude of the mechanical deformation (stretch or compression). The theoretical formula for the resistance strain effect is as follows: [0003] [0004] Where R is its resistance value, ρ is the resistivity of the metal material, L is the length of the metal material, and S is the cross-sectional area of ​​the metal material. During the process of mechanical deformation of the metal wire under strain, ρ, L, and S will all change, which will inevitably cause changes in the resistance value of the metal material. When the metal material is stretched, the length increases, the cross-sectional area decreases, and the resistance value increases; ...

AI Technical Summary

Problems solved by technology

[0013] In order to overcome the deficiency that the existing metal strain gauges cannot detect the strain deflection, the present invention provides a measurable axial distribution of the axial deflection of the outer axial deflection of the single-sided sheet, which can not only measure the strain but also effectively detect the axial deflection of the surface strain. Sparse interdigitated metal strain gauges in the five sensitive grids, especially for measuring the corners and edges of the workpiece where the size of the strain gauges is limited or other axial first-order deflectors that are not suitable for the location of the strain gauges.

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