Tensile test method and device for cable insulation dumbbell test piece

Abstract

The invention discloses a tensile test method and device for a cable insulation dumbbell test piece. The method comprises the following steps: marking: making upper marking lines at the upper ends of N prepared test pieces, making lower marking lines at the lower ends, and setting the distance between the inner sides of the upper marking lines and the lower marking lines as a, wherein the length of each of the upper marking line and the lower marking line is b; heating: placing the N marked test pieces in an experimental device, respectively connecting upper tensile machines to the upper ends of the test pieces, respectively connecting automatic clamps to the lower ends of the test pieces, and arranging cameras outside the experimental device for shooting images of the test pieces at different time points in the experimental device; acquiring an image; calculating a vertical deformation rate according to the M groups of image data; and calculating the transverse deformation rate according to the M groups of image data. According to the invention, the position of the marking line can be accurately determined, the elongation can be calculated, unqualified test pieces can be automatically found, and the detection is convenient.

Description

technical field [0001] The invention relates to a cable insulation test, in particular to a tensile test method and device for a cable insulation dumbbell test piece. Background technique [0002] A cable is usually made of one or more mutually insulated conductors and an outer insulating layer, which belongs to the wire that transmits power or information from one place to another. [0003] Thermal extension test is an inspection method to assess the load deformation and permanent deformation of cable insulation or sheath under heat and load. If the cable insulation or sheath deforms under high temperature load, it will lose mechanical properties and even cause a short circuit. Affect the normal use of the cable. At present, the commonly used test method is to make the cable insulation into the shape of a dumbbell specimen as the basic specimen for testing, then fix the upper end of the dumbbell specimen in the experimental device, clamp a clip at its lower end, and gradua...

AI Technical Summary

Problems solved by technology

[0003] Thermal extension test is an inspection method to assess the load deformation and permanent deformation of cable insulation or sheath under heat and load. If the cable insulation or sheath deforms under high temperature load, it will lose mechanical properties and even cause a short circuit. Affect the normal use of the cable

At present, the commonly used test method is to make the cable insulation into the shape of a dumbbell specimen as the basic specimen for testing, then fix the upper end of the dumbbell specimen in the experimental device, clamp a clip at its lower end, and gradually Place weights, and determine the elongation of the cable insulation according to the weight of the weights and the time of the experimental device. This test method requires frequent opening of the door of the experimental device to add weights, resulting in frequent changes in the temperature in the experimental device, and the appearance of weights The inclination of the tension caused by the skewed placement of yards will eventually lead to inaccurate final length measurement and inaccurate elongation calculation

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