Device and test method for testing circumferential fracture toughness of thin-wall pipe

Abstract

The invention discloses a device and test method for testing circumferential fracture toughness of a thin-wall pipe. The device comprises a disc-shaped clamping device, two connecting devices and fixing pins for fixing the clamping device and the connecting devices; the clamping device is divided into two semicircular slices with different sizes, and fixing holes are formed in both of the semicircular slices; each connecting device comprises a connecting handle and a Pi-shaped connector, the connecting handle is fixed with the center of a cross beam of the connector, and pin holes are formed in both of two side walls of the connector. The method comprises the following steps of: (i) measuring the size of the thin-wall pipe; (ii) mounting the device; (iii) prefabricating cracks;(iv) testing the circumferential fracture toughness; and (v) calculating the circumferential fracture toughness. According to the invention, annular specimen cracks are prefabricated without loss, the fracture toughness is tested through a simple tension test to avoid specimen defects brought about in a specimen bending process, and the circumferential fracture toughness of the thin-wall metal pipe can be accurately and directly tested.

Description

technical field [0001] The invention belongs to an experimental device for the fracture toughness of a sample, in particular to a device and a test method for testing the circumferential fracture toughness of a thin-walled pipe. Background technique [0002] As the main structural parts, small-diameter thin-walled metal pipes are subjected to hoop stress. Only the hoop fracture toughness can truly reflect the real stress situation. [0003] At present, there is no standard for testing the hoop mechanical properties of thin-walled metal pipes. It needs to be explored and studied by itself. In the past, tensile tests have used samples with bending. During the loading process of the samples, due to the generation of bending distance The introduction of additional stress seriously affects the accuracy of the test data, and also leads to the inability to accurately judge the law between the production process and the mechanical properties. Therefore, it is necessary to design a s...

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Problems solved by technology

[0003] At present, there is no standard for testing the hoop mechanical properties of thin-walled metal pipes. It needs to be explored and studied by itself. In the past, tensile tests have used samples with bending. During the loading process of the samples, due to the generation of bending distance The introduction of additional stress seriously affects the accuracy of the test data, and also leads to the inability to accurately judge the law between the production process and the mechanical properties. Therefore, it is necessary to design a special test for the circumferential fracture toughness of small-diameter thin-walled metal pipes. experimental device

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