SU681366A1

SU681366A1 - Method of the ultrasonic control of condition of a material

Info

Publication number: SU681366A1
Application number: SU772543869A
Authority: SU
Inventors: Георгий Трофимович Продайвода; Михаил Иванович Толстой
Original assignee: Киевский Ордена Ленина Государственный Университет Им.Т.Г.Шевченко
Priority date: 1977-11-09
Filing date: 1977-11-09
Publication date: 1979-08-25

Description

(54) СПОСОБ УЛЬТРАЗВУКОВОГО КОНТРОЛЯ СОСТОЯНИЯ МАТЕРИАЛОВ(54) METHOD OF ULTRASONIC CONTROL OF THE CONDITION OF MATERIALS

материалов дополнительно прикладывают механическую нагрузку, направление которой согласуют с элементами симметрии акустического тензора.и по величине относительного изменен1 его главных значений определ ют величины механических напр жений в материале .materials additionally apply a mechanical load, the direction of which is consistent with the symmetry elements of the acoustic tensor. and the magnitude of the relative change1 of its principal values determines the magnitudes of the mechanical stresses in the material.

Способ заключаетс в следующем. В материале возбуждают в каждом из шести (или более) неэквивалентных произвольно заданных направлений ультразвуковые продольную и две поперечные линейно пол ризованные волны , плоскости пол ризации которых взаимно ортогональны. Вычисл ют дл каждого направлени величину, равную сумме квадратов скоростей ульразвуковых волн, и составл ют матрицу компонент акустического тензора:The method is as follows. The material excites in each of six (or more) nonequivalent arbitrarily specified directions ultrasonic longitudinal and two transverse linearly polarized waves, the polarization planes of which are mutually orthogonal. For each direction, a value equal to the sum of the squares of the velocities of the ultrasonic waves is calculated, and the matrix of the components of the acoustic tensor is composed:

(Ъ20 (B20

. ,. ,

в которой благодар свойствам симмет- 25 ричности число неэависиг влх констант сокращаетс до шести -,.- where, due to symmetry properties, the number of unavoidable constants is reduced to six -, .-

.(З. . . (H.

Затем рассчитывают главные значе ни акустического тензора одним из известных способов (решением характеристического уравнени акустического тензора или методом последовательных приближений с использованием свой ства радиуса - вектора характеристической поверхности акустического тензора ) и по ним суд т об элементах симметрии текстуры.Then, the principal values of the acoustic tensor are calculated by one of the known methods (by solving the characteristic equation of the acoustic tensor or by the method of successive approximations using the radius property — the vector of the characteristic surface of the acoustic tensor) and the symmetry elements of the texture are judged by them.

Дл определени напр жений дополнительно нагружают материал извне и измер пот акустический тензор. Сравнивают значение тензоров материала до и после нагружени и по величине изменени суд т о величинах механических напр жений в материале.To determine the stresses, the material is additionally loaded from the outside and the acoustic tensor is measured. The value of the material tensors before and after loading is compared and the magnitude of the change is judged on the magnitudes of the mechanical stresses in the material.

Claims

Claim 1. Ultrasonic monitoring of the state of materials, which consists in exciting longitudinal and transverse ultrasonic waves in the material, measuring their propagation speeds and judging them about the state of the material, characterized in that, in order to increase the accuracy and the control performance of anisotropic materials, excite one longitudinal wave and two transverse linearly polarized waves, the polarization planes of which are mutually orthogonal, and the propagation speeds of the waves are measured along not It six nonequivalent arbitrarily given directions, determined components of a symmetric second order tensor acoustic

.

where v

—the velocity of the idiol wave in a given direction;

V, Vj are the velocities of the transverse waves propagating in the same direction, but with perpendicular directions of displacement in the wave, and its main values are judged on the elements of symmetry of the texture.

2. Method POP.1, characterized in that, in order to determine the stress state of inhomogeneous anisotropic materials, a mechanical load is additionally applied, the direction of which is consistent with the symmetry elements of the acoustic tensor, and the magnitudes of the mechanical stresses are determined by the magnitude of the relative change in its main values zheny in the material.

Sources of information are taken into account in the examination

1. Geologists of ore deposits, vol. 15, 1973, No. 5, p. 19-31.

2. USSR author's certificate number 191867, cl. G 01 L 1/14, 1969.