Non-contact measuring device for plastic strain ratio r value of metal sheet

Abstract

The utility model discloses a non-contact measuring device for the plastic strain ratio r value of a metal sheet, which comprises a video extensometer, a metal sheet sample and a background light source b, a support is arranged on the lower side of the video extensometer, and a light source a emitting strip-shaped structured light is installed on the support in a hinged mode. The metal sheet sample and the background light source b are both located right in front of the video extensometer, and the metal sheet sample is located between a lens of the video extensometer and the background light source b. Through ingenious combination of the video extensometer, the strip-shaped structure light source and the parallel background light source, non-contact measurement is carried out on axial and transverse deformation of the metal sheet in the stretching process, so that the plastic strain ratio r value of the metal sheet is calculated. Compared with a contact type extensometer, the extensometer does not need to be manually mounted and dismounted before and in the test, the manual operation intensity is reduced, the personal error in the measurement process is reduced, the measurement mode is a non-contact mode, and the problems of abrasion, precision drift and damage do not exist.

Description

Technical Field

[0001] The utility model relates to the technical field of measuring equipment, in particular to a non-contact measuring device for the plastic strain ratio r value of a metal sheet. Background Art

[0002] In the process of measuring the plastic strain ratio r value of metal sheets, the traditional method is to use two contact extensometers, namely a transverse contact extensometer and an axial contact extensometer, which measure the axial and transverse deformation of the metal sheet respectively. During the stretching process, the two contact extensometers need to be clamped on the metal sheet for tracking measurement. This type of measurement method has the following defects: the contact method between the transverse contact extensometer and the thin plate sample is usually a blade type. During the measurement process, the blade may slip and there is a problem of accuracy drift in long-term use. These are common problems of contact extensometers. The problems are: the contact point between the blade of the lateral contact extensometer and the metal sheet will cause stress concentration at the contact point, resulting in irregular lateral shrinkage deformation; the axial and lateral deformation of the metal sheet during the stretching process need to be measured separately by two extensometers, and the two extensometers need to be manually installed on the metal sheet specimen before the test, and then the two extensometers need to be manually removed before the metal sheet specimen is broken to prevent the impact energy when the thin plate specimen is broken from damaging the two extensometers. The above defects will cause the measured values ​​to be more discrete, resulting in low measurement accuracy. Utility Model Content

[0003] The utility model aims to provide a non-contact measuring device for the plastic strain ratio r value of a metal sheet, so as to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a non-contact measuring device for the plastic strain ratio r value of a metal sheet, comprising a video extensometer, which is applied to the measurement of a metal sheet sample, and also comprises a background light source b capable of emitting parallel light, a bracket is arranged at the lower side of the video extensometer, a light source a emitting strip structured light is hingedly mounted on the bracket, the metal sheet sample and the background light source b are both located directly in front of the video extensometer, the metal sheet sample is located between the lens of the video extensometer and the background light source b, and the light source a shines on the side of the metal sheet sample.

[0005] Preferably, the light source a is hinged to the bracket via a damping shaft, so that the angle of the light source a can be fixed after being flipped.

[0006] Preferably, the width of the background light source b is greater than the width of the metal sheet sample.

[0007] Compared with the prior art, the utility model has the following beneficial effects: the axial and lateral deformation of the metal sheet during the stretching process is measured non-contactly by the ingenious combination of the video extensometer, the strip structure light source and the parallel background light source, so as to calculate the plastic strain ratio r value of the metal sheet. Compared with the contact extensometer, it is no longer necessary to manually install and remove the extensometer before and during the test, which reduces the intensity of manual operation and the human error in the measurement process. The measurement method is non-contact, so there is no problem of wear, precision drift and damage like the contact extensometer. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of the structure of the utility model;

[0009] Figure 2 It is a schematic diagram of the use state of the utility model.

[0010] In the figure: 1. Video extensometer; 2. Background light source b; 3. Light source a; 4. Bracket; 5. Metal sheet specimen; 6. Tensile fixture. DETAILED DESCRIPTION

[0011] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0012] See also Figure 1-2 The utility model provides a technical solution: a non-contact measuring device for the plastic strain ratio r value of a metal sheet, comprising a video extensometer 1, the video extensometer 1 is applied to the measurement of a metal sheet sample 5, and also comprises a background light source b2 capable of emitting parallel light, a bracket 4 is arranged at the lower side of the video extensometer 1, a light source a3 emitting strip structured light is hingedly mounted on the bracket 4, the light source a3 is hingedly connected to the bracket 4 through a damping shaft, the light source a3 can be fixed at an angle after flipping, the metal sheet sample 5 and the background light source b2 are both located in front of the video extensometer 1, the metal sheet sample 5 is located between the lens of the video extensometer 1 and the background light source b2, and the light source a3 illuminates the side of the metal sheet sample 5. The width of the background light source b2 is greater than the width of the metal sheet sample 5, and the metal sheet sample 5 can well display the width under the background light source.

[0013] Since the metal sheet sample 5 blocks the parallel light emitted from the background light source b2, part of the light enters the video extensometer 1, so the video extensometer 1 can distinguish the width of the metal sheet sample 5, and thus can measure the lateral shrinkage deformation of the metal sheet sample 5 during the tensile test; the strip-shaped light spot emitted by the light source a3 is responsible for illuminating the middle area of ​​the metal sheet sample 5, so the video extensometer 1 can observe the characteristics of the illuminated area in the middle of the metal sheet sample 5, so that the video extensometer 1 can measure the axial extension deformation of the metal sheet during the tensile test.

[0014] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A non-contact measuring device for the plastic strain ratio r value of a metal sheet, comprising a video extensometer (1), the video extensometer (1) being applied to the measurement of a metal sheet specimen (5), characterized in that: The video extensometer (1) further comprises a background light source b (2) capable of emitting parallel light. A bracket (4) is arranged at the lower side of the video extensometer (1). A light source a (3) emitting strip-shaped structured light is hingedly mounted on the bracket (4). The metal sheet sample (5) and the background light source b (2) are both located directly in front of the video extensometer (1). The metal sheet sample (5) is located between the lens of the video extensometer (1) and the background light source b (2). The light source a (3) illuminates the side of the metal sheet sample (5).

2. The non-contact measuring device for the plastic strain ratio r value of a metal sheet according to claim 1, characterized in that: The light source a (3) and the bracket (4) are hinged via a damping shaft, so that the angle of the light source a (3) can be fixed after being flipped.

3. The non-contact measuring device for the plastic strain ratio r value of a metal sheet according to claim 1, characterized in that: The width of the background light source b (2) is greater than the width of the metal sheet sample (5).

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