IMPROVEMENT OF METHODS OF APPLICATION OF MECHANICAL METHODS OF NON-DESTRUCTIVE CONTROL

Abstract

Problem statement. Standardized and design parameters of concrete usually differ from the actual values obtained by the concrete of a structure during construction. The use of non-destructive testing devices usually requires their calibration, which is carried out by the vast majority only based on the results of determining the physical and mechanical characteristics of concrete of cubic samples. However, since the conditions of concrete formation and curing in the samples and the structure differ, the existing methods do not adequately reflect the properties of the concrete in the structure. Experience in the use of ultrasonic devices and personal research to improve the ultrasonic method allowed us to recommend limiting the scope of this method to periodic monitoring, since this method can easily and accurately track relative changes in the material of the structure. However, to assess the technical condition of structures, not only relative but also absolute values of the PhMC of the structure material are required. Such data, according to preliminary considerations, can be obtained with proper reliability only by using mechanical methods of non-destructive testing. The purpose of the article is determination of the way to improve the methodology for application of mechanical non-destructive testing methods. Results. The possibility of direct determination of the elastic modulus during the interaction of an indenter with a semi-infinite space with elastic-plastic properties is considered. Four stages of interaction are distinguished, depending on the nature of the forces that provide the indenter's motion, as well as the type and number of system elements involved in the interaction. The equations of conservation of the amount of motion in the system are created and the results of their solution are analyzed. Conclusions. The analysis of the conducted studies shows that it is quite difficult to obtain a solution with the necessary indicators at acceptable costs. At the same time, the reliability of the results obtained is low. To reveal the resulting uncertainty, it is necessary to introduce additional equations into the system, which can be created on the basis of additional measurements. Thus, improvement of the methodology for determining the properties of materials requires modification of the system of equations and additional measurements with subsequent calculations.