INFLUENCE OF CORROSIVE WEAR ON THE BEARING CAPACITY OF METAL SUPPORT OF SVP PROFILE AND THE REDUCTION OF ITS SERVICE LIFE
Authors:   National Technical University «Dnipro Polytechnic», Gapeev Serhii , Kovalenko Vladyslav ,   National Technical University «Dnipro Polytechnic»
Published: July 2023

Purpose. Determining the effect of corrosion wear on the change in the load-bearing capacity of a metal fastener due to the moment of resistance of the cross section of the SVP profile and providing recommendations for the timely replacement of metal fasteners damaged by corrosion. Methods. Laboratory studies of the dependence of the corrosion rate of St5ps steel on the time of observation under conditions of periodic wetting with aggressive mine waters were carried out. When conducting corrosion tests, quantitative methods of corrosion rate estimation were used, which include the weight method. Using the provisions of construction mechanics, analytical studies of the change in the moment of resistance of the cross-section of the SVP profile from corrosive wear were carried out Results. It is defined the dependences of the corrosion rate of St5ps steel on the time of observations. In the analytical studies of the change in the moment of resistance of the SVP profile section due to corrosion wear, the calculation was carried out for the case of uniform corrosion over the entire surface of the SVP profile section at the same speed. The moments of cross-sectional resistance (W) of SVP-17, 22, 27, 33 profiles were determined considering corrosion wear at a corrosion rate of 0.24 mm/year. Changes in the load-bearing capacity of the fastener due to the axial moment of resistance of the SVP profile from corrosive wear are determined. The assessment of the impact of corrosion wear on the load-bearing capacity of fasteners from the SVP profile is based on the requirements for rejecting corroding metal frames for reuse (SOU 10.1.00185790.011:2007). Recommendations are provided for the timely replacement of metal fasteners damaged by corrosion. The originality. It is proposed a methodology for determining the loss of the load-bearing capacity of the profile (in %) from the time of its operation under the action of mine water during the period when the minimum permissible wall thickness of the SVP profile is reached. Practical implementation. The use of the proposed method of determining the loss of the load-bearing capacity of the profile (in %) from the time of its operation under the action of mine water allows to significantly increase the stability of products fixed with metal fasteners, as well as to establish critical time ranges for SVP profiles 17, 22, 27, 33, in which a critical decrease in the load-bearing capacity of corrosion-prone fastening frames should be expected and a decision to restore the load-bearing capacity of the support in mine working should be made. In the calculations of the required number of supporting frames, it is proposed to use the correction coefficient of corrosion wear, which characterizes the degree of loss of the load-bearing capacity of the profile and support. Keywords: corrosion wear, metal samples, moment of section resistance (W), SVP profiles, loss of bearing capacity.