SU1300378A1 - Ultrasonic transducer with variable radiation-reception angle - Google Patents

Abstract

This invention relates to the field of non-destructive testing. The aim of the invention is to extend the functionality by changing the angle of radiation-reception. On the wedge-shaped prism 1, a phased antenna array 2 of n piezoelectric elements 3 connected to the control unit 4 is fixed. To provide the required angle of incidence q from the outputs of the control unit 4 to the piezoelectric elements 3, harmonic signals are sent with the same phase shift t between adjacent piezoelectric elements 3. The choice of the geometrical parameters of the prism 1 ensures the required angle b of radiation. 2 Il. Fib.G

Description

The invention relates to the field of non-destructive tools and methods of control and can be used for ultrasonic testing of materials.

The purpose of the invention is to expand the functionality of the converter by changing the angle of radiation-reception.

FIG. 1 shows an ultrasonic transducer (UZP). With a variable angle of radiation — reception; in fig. 2 - a prism with a phased antenna array mounted on it, longitudinal section.

An ultrasonic transducer with a variable angle of radiation — the reception contains a wedge-shaped acoustic transducer 1 with a phased antenna array 2 rigidly fixed on its upper surface 2 of n piezoelectric elements 3 and an emission angle control assembly 4 — a reception of the SPD grating 2. Position 5 marked the sample of the material under study.

In the mode of radiation, the piezoelectric elements 3 of the phased array 2 are washed away from the node 4 of the control of the angle of emission-reception. With common-mode power piezoelements. 3 The radiation of the acoustic wave by the antenna array 2 occurs in the body of the prism 1 perpendicular to the plane of the antenna array 2. The height of the prism 1 from the middle of the antenna

2

lattice 2 is 1a -, where the length of the acoustic wave in the prism material, d is the base of the lattice.

Ultrasonic transducer with

The 35k energies of the retreat from the normal to its surface will lie within the width of the directivity of the antenna array 2 at

angles 0. and b, the composition of it and the correspondingly-variable angle of radiation — reception is 40 but 0, and A,. Fsna working surplus t g gtrrTVtnmttr rifnt a nvt I

the prism stems are determined from the ratio

bots as follows.

Prism 1 is installed on the surface of the material under study 5, providing acoustic contact between the working surface of the prism 1 and the surface of the material under study 5. When emitted, the acoustic wave passes through the body of the prism I, and the prism 1 falls onto the interface - the material under study 5 at an angle C) , it breaks at the interface and spreads in the test material. In this case, a body or surface wave can propagate in the body of the material under study 5. The type of wave is determined by the ratio of the velocity (Vnp) of the acoustic wave propagation in the prism body 1 n of the velocity (v) of the acoustic wave.

2

) E and h-cos (y-9j- |) tg (p9, + -tg (y -Og- |) j,

I.

where is the wedge angle of the prism;

9, and 9 are the angles of deviation of the maximum radiation of the lattice energy from the normal to its surface, clockwise and against, respectively; f and ij is the width of the directional characteristic of the grating at angle b, and © g

wave in the material under study 5 and depends on the angle of incidence Cf. If the values of if are smaller than the second critical angle tp.

equal

Cf j arcsin

Vn vu

in the material under study 5, a volume acoustic wave propagates, and with a Cp value equal to the second critical angle, in the material under study 5 a surface acoustic wave propagates.

To ensure the required angle (p dropping, it is necessary to provide an appropriate angle for the deviation of the maximum radiation from the antenna array 2 from the normal to its surface. This is achieved by harmonic signals at the radiation frequency at the output of the radiation angle control unit on the piezoselems 3 of the antenna retesh 2 a phase shift t between adjacent piezoelectric elements 3, providing the required radiation angle 0, which is determined by the value of t.

If the ultrasonic transducer must provide angles of incidence of the acoustic wave at the interface of the prism 1 - material 5 within qj,...., Cf 2, then the corresponding angles of deflection of the maximum energy of the retret from the normal to its surface will lie within the width of the antenna pattern 2 at

angles 0. and b, the composition of it and, respectively, 0, and A,. working surface

2

) and h-cos (y-9j- |) tg (p9, + -tg (y -Og- |) j,

.

de - wedge angle of the prism;

9, and 9 are the angles of deviation of the maximum radiation of the lattice energy from the normal to its surface, clockwise and against, respectively; f and ij is the width of the directional characteristic of the grating at angle b, and © g

P

UZP with a variable angle of radiation -

reception allows one to excite surface waves in a wide class of materials.

Claims (1)

Invention Formula An ultrasonic transducer with a variable angle of radiation, containing an antenna array of piezoelectric elements and a node for controlling the angle of radiation, receiving electrically connected with each piezoelectric element of the lattice, characterized in that it is equipped with a wedge-shaped prism, height h from the middle of the lattice of the piezoelectric elements and the working surface 1 of which are determined from the ratios fiz, r  hcos () jtp (y + 0, + | i-). -t.g (y9.-4),  n Q prism wedge; O, and the angles of deviation of the maximum radiation of the lattice energy from the normal to its surface, respectively, clockwise and against; RT - and Pr - width of the directivity pattern of the lattice, respectively, at an angle of e, u0,;  - wavelength in the material - prisms; d - base antenna array. B d.2