DOI: 10.14489/td.2025.10.pp.004-011

Danilov V. N.
ABOUT DGS-DIAGRAM OF A NORMAL PROBE AND FLAT BOTTOM HOLES OF VARIOUS SHAPES OF THE SAME ARE
(с. 4-11)

Abstract. Based on the previously developed algorithm for determining the relative pressure on a normal probe of a longitudinal wave reflected from a flat bottom hole (taking into account the impossibility of “flowing around” the hole with a wave) when the center of the hole is located on the axis of a normal circular probe in a quasi-monochromatic approximation, numerical calculation and comparison of DGS-diagrams for flat bottomed holes of various shapes ‒ round, elliptical, square and triangular the same area. It is shown that with a decrease in the ratio of the areas of flat bottom holes of various shapes and the piezoelectric plate of the probe, there is a tendency to reduce the difference between the largest and smallest values of the DGS-diagrams for the values of the range to the holes, where their noticeable differences are observed. In all cases of the evaluation of the deviation of the diagram values when changing the shape of the hole, such a deviation from the average value (for a fixed range to the reflector) was less than ±1 dB.

Keywords: DGS-diagram, normal probe, flat bottom hole, near zone, piezoelectric plate area, flat bottom hole shape, elliptical hole, square shape, triangular shape.