ALGORITHM FOR CALCULATING GROUP AND PHASE PROPAGATION VELOCITIES OF ULTRASONIC DIRECTED MODES IN THE WALLS OF METAL STRUCTURES

Abstract

The paper presents an algorithm for calculating the phase and group velocities of ultrasonic guided modes in the walls of metal structures. The theoretical part is presented, which mathematically describes the parameters of ultrasonic wave modes and provides the physical basis for using the algorithm. The work presents and substantiates the need to control metal structures based on main pipelines. Photographs of unusual situations associated with landslides are shown, and an analysis of the factors is given. which affects the technical condition of metal structures. The reasons for the control of metal structures to clarify the influence of abnormal situations on the change in the level of technical condition are substantiated. The constructed algorithm for calculating the phase and group velocities of ultrasonic guided modes is presented graphically and the main blocks of its work are explained. The algorithm was implemented in the MatLab programming language, as it was justified to use the language to perform complex mathematical calculations and graphically present the results with the possibility of further analysis. The algorithm consists of components that are implemented in the form of subroutines, which provides construction logic and the possibility of reusing the code of the algorithm program. The algorithm solves the mathematical problem of finding the modes of ultrasonic guided waves in a waveguide, therefore the paper presents the conditions for applying the results of the algorithm for monitoring in real conditions. The description and sequence of operations that must be performed for the successful configuration of the structure from generating and receiving ultrasonic primary transducers are given. For the possibility of spot control of algorithm results and laboratory practical measurements of guided wave parameters, a table of results with numerical values of wave amplitude and coordinates of its registration is presented. That will allow more precise adjustment of laboratory studies. The obtained deviations of the results in the real conditions of control from those given in the work will make it possible to conduct a more detailed analysis of changes in the technical condition of the object under study. The conclusions of the research results are presented.