A test method for interface fracture toughness of second-generation high-temperature superconducting strips

Abstract

The invention provides a second-generation high-temperature superconducting strip interface fracture toughness test method, which includes the following steps: (1) solidifying a reinforcing layer with a thickness much larger than that on both sides of the superconducting strip to form a composite beam structure and serve as a Test sample; (2) Coat the speckle on the narrow side of the sample length direction; (3) Cut the initial crack at one end of the sample superconducting strip, then load the sample on the tensile machine, and the CCD Aim the camera at the speckle-coated side of the sample; (4) Carry out Type I and Type II interlaminar fracture experiments respectively; (5) Use the digital image correlation method to calculate the Type I and Type II interlaminar fractures of the sample Toughness, the result is the type I and type II interlaminar fracture toughness of the superconducting tape. In the present invention, by adding a reinforcing layer with a thickness much larger than the superconducting strip on both sides of the superconducting strip, the fracture toughness of the superconducting strip can be measured by a conventional experimental method, and the experimental method is simple and has high accuracy.

Description

technical field [0001] The invention belongs to the technical field of superconducting strip experiments, and relates to a second-generation high-temperature superconducting strip interface fracture toughness test method. Background technique [0002] The second-generation high-temperature superconducting tape is a typical laminated composite material, and the interface peeling between layers often occurs, which seriously affects the use of the tape. Since the thickness of the second-generation high-temperature superconducting strip is very thin (thickness is about 0.1 mm), and it has an asymmetric structure along the thickness direction of the material, such structural features make it difficult to capture the deformation characteristics of superconducting materials, especially the crack tip during deformation. . In addition, because the superconducting tape is very thin, it is difficult to test it with the traditional method of testing the interface fracture toughness of ...

AI Technical Summary

Problems solved by technology

[0002] The second-generation high-temperature superconducting tape is a typical laminated composite material, and interlayer delamination often occurs, which seriously affects the use of the tape.

In addition, due to the thinness of the superconducting tape, it is difficult to test it with the traditional method of testing the interface fracture toughness of composite materials

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