Identification of Cross-Section Defects of the Rod by Using Eigenfrequencies and Features of the Shape of Longitudinal Oscillations

Abstract

A method is proposed for solving inverse flaw detection problems for rods performing longitudinal oscillations. Based on the modeling of the cross-sectional defect as a known function, the main parameters characterizing it, such as the location and volume of the two lowest oscillation frequencies of the free and cantilevered rods, will be approximately determined. Using numerical simulations, it is shown that to satisfactorily determine the properties of a defect, it is sufficient to use several lower frequencies. A method for identifying a defect by one lowest frequency of a free rod is also proposed, provided the known location of the defect is applied, for which it is necessary to determine the characteristics of the oscillation modes. The results of an experimental study are presented.