METHOD FOR DETERMINING THE ENDURANCE LIMIT OF THE MATERIAL OF A CYLINDRICAL PART UNDER TORSION Russian patent published in 2022 - IPC G01N3/40 

FIELD: material research.

SUBSTANCE: invention relates to the field of determining the strength properties of metals and can be used to determine the limit of torsion endurance without destroying the material of parts operating under loading conditions with a time-varying torque. Essence: the radii of curvature of the surface of the test material of a cylindrical part and a cylindrical indenter are measured, the mismatch radius of curvature R_mis is determined. The surface of the test material of the cylindrical part is loaded by means of a cylindrical indenter at an angle of crossing 90° of its axis to the axis of the cylindrical part with two different loads F₁ and F₂ corresponding to the hardness measurement. The depths h₁ and h₂ of the two obtained residual prints are measured from the point of initial contact of the cylindrical indenter with the cylindrical part. The torsion endurance limit is calculated according to the dependence, taking into account the coefficients of fatigue strength under torsion.

EFFECT: simplification of the method for determining the endurance limit of the material of a cylindrical part during torsion and increasing its accuracy.

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