METHOD FOR DETERMINING THRESHOLD OF FATIGUE CRACK NONPROLIFERATION AT HIGH FREQUENCY Russian patent published in 2017 - IPC G01N3/38 

FIELD: measuring equipment.

SUBSTANCE: cyclic load (32, 32A) acts on, at least, one test sample having an elliptical hole (12) in the test area (10A), with an elliptical opening having a notch (14) at one end, and the test sample is held between two rigid masses (24, 26) by two rigid plates (20, 22) of the prestress, located on each side of the said, at least, one test sample, and each of which is attached at its two ends (20A, 22A; 20B, 22B) to two rigid masses, wherein the cycle load has a frequency, which is selected equal to the resonant frequency of the node containing the test sample, the masses and the prestress plates for the formation of a fatigue crack of the said notch, then, after determining the crack distribution stop, the final crack length is measured, and for determining the threshold of the ΔK_th nonproliferation of the fatigue cracks, a chart is used, wherein the cyclic load is provided with an electromagnetic vibrator (32) rigidly attached through rigid struts to the structure that supports the two rigid masses containing the stem (32A) to transfer the cyclic load to the specified node containing the test sample, the masses and the prestress plates.

EFFECT: possibility of determining the threshold of the fatigue crack nonproliferation at a high frequency in a design test sample having a specific shape.

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