DOI: 10.14489/td.2019.01.pp.032-037

Konovalov A. M., Kugushev V. I., Yakovlev A. Yu.
IMPEDANCE SENSOR FOR NON-DESTRUCTIVE TESTING OF RIGID METAL STRUCTURES
(pp. 32-37)

Abstract. The article describes impedance flaw detector transducer that has a rod divided across into two parts connected with springs. Thus, upper portion of the rod excited by piezoelectric element can freely generate oscillations and transmit them to the object under test through lower part tightly pressed to solid surface of the object. Change in the mass of the upper portion of the rod and rigidity of springs allows to tune frequency of generated oscillations to frequency of natural oscillations of the object under test, and to separate their amplitude from the general spectrum of mechanical oscillations. This may be done if the sensor consists of two transducers, transducer-oscillation generator and transducer-receiver installed permanently in different parts of the object. Flaw detection of the object under test for availability and development of cracks and residual stresses is made with respect to variation of the amplitude of natural oscillations. Use of the suggested sensor enables to carry out an integrated non-destructive testing of metal structures in whole or their elements separately, including those that have no direct access. This kind of testing may be easily computerized. Results demonstrating operation of the sensor both in separate and combined mode are presented.

Keywords: impedance transducer, rod, piezoelectric element, natural oscillations, flaw detection, integrated computerized testing.