Test piece for realizing biaxial stress state through uniaxial loading of spherical working section

Abstract

The invention discloses a test piece for realizing a biaxial stress state through uniaxial loading of a spherical working section. The test piece is integrally of a plate-shaped structure, the middlepart is a working section, the left and right sides are clamping sections, the working section is of a rhombic structure, and the two sides of two diagonal lines are partially symmetrical. Spherical recesses and special-shaped holes are designed in the working section; the spherical recesses are designed on the front and back surfaces of the working section and are positioned in the center of theworking section; the number of the special-shaped holes is four, and the four special-shaped holes are formed in the four parts, equally divided by the two angular bisectors, of the working section respectively. Loading of the test piece is achieved through a uniaxial fatigue testing machine, under the designed spherical recesses and special-shaped holes, a multi-axial stress state of stretching in the horizontal direction and compressing in the vertical direction is finally generated in the center of the whole test piece, and a typical tension / compression multi-axial stress state is formed. According to the invention, simulation of the tension and pressure biaxial state of the disc center of a turbine disc can be realized, part-level assessment tests can be partially replaced, the structural design period is shortened, and the test cost is saved.

Description

technical field [0001] The invention belongs to the technical field of mechanical structure strength assessment and simulation part design, and is a test piece aimed at the uniaxial loading of the spherical working section to realize the biaxial stress state. The force state can reflect the stress characteristics of the structure. Background technique [0002] At present, in typical structures of turbomachinery blades, discs, shafts, etc., including aeroengines and internal combustion engines, stress concentration locations such as hole edges and fillets are key parts that are prone to fatigue cracks and subsequent damage. In order to ensure the safety of these positions, it is usually necessary to carry out strength assessment through tests, especially fatigue strength assessment. For components, it is undoubtedly a long cycle and high cost to carry out component-level tests for overall structural assessment. At the same time, there are many uncontrollable factors in the t...

AI Technical Summary

Problems solved by technology

[0004] For the designed multi-axial fatigue test piece, the test is usually carried out on a multi-axial fatigue testing machine, which brings another difficulty in the research process, that is, the way of applying the load is greatly restricted

Using a multi-axial fatigue testing machine to load, the test cost is also high, and the load is usually a tensile torsion load, which is more limited

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