Tester for measuring real stress-strain curve of plate material under unidirectional compression state

Abstract

The invention discloses a tester for measuring a real stress-strain curve of a plate material under a unidirectional compression state. The lower surface of an upper die seat is attached to the upper surface of an upper puncher pin base; the upper surface of a lower die seat is attached to the lower surface of a lower puncher pin base; an upper insert is fixed on the lower surface of the upper die seat and used for fixedly connecting an upper puncher pin with the upper die seat; the lower puncher pin base is positioned in the center of the upper surface of the lower die seat; a lower insert is opposite to the upper insert; a measurement frame is positioned at the same end of the tester; and a measurement rod of the measurement frame is in sliding fit with the inner hole of an upper strut.A plate material test piece is arranged horizontally, so that the plate material test piece cannot be unstably bent during compression, and large-extent compression deformation is realized; and therefore, the real stress-strain curve of the plate material under a large deformation extent is obtained.

Description

Technical field [0001] The invention relates to the field of cold working, in particular to a test device for measuring the true stress-strain curve of a sheet in a unidirectional compression state based on a rolling test. technical background [0002] Establishing an accurate constitutive equation is an important prerequisite for solving the problem of metal plastic forming, and the constitutive equation can be established through unidirectional uniform tensile, compression or pure shear tests. According to different plastic deformation states, different test methods are selected. At present, to study the mechanical properties of sheet metal under compression, domestic and foreign scholars mostly adopt the metal sheet compression test method similar to the national standard GB / T7314-2005, that is, the sheet metal specimen is placed vertically, the bottom end of the long axis is fixed and the upper end Under compression, both ends of the short shaft are free and unconstrained. A...

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Problems solved by technology

[0003] In order to overcome the disadvantages existing in the prior art that it is difficult to effectively eliminate the end surface friction force and cannot truly reflect the mechanical properties of the sheet metal under unidirectional compression, the present invention proposes a method for measuring the true stress-strain of the sheet material under the unidirectional compression state. curve test device

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