A.N. Vorontsov, Cand. Sci. (Eng.), Lead Specialist, avorontsov@intron.ru V.Yu. Volokhovsky, Cand. Sci. (Eng.), Lead Specialist INTRON PLUS, Ltd., Moscow, Russia
Two approaches to assessment of strength and individual residual resource of guy lines steel ropes of antenna mast structures with the use of data of the operative diagnostics by the method of Hall effect are considered. The principles of strength assessment of the ropes with defects in the presence of two diagnostic indicators are stated (the distributed loss of the bearing rope section on metal due to corrosion and local breaks of wires). As mechanical model the structural theory of steel ropes is used, which describes their design as the system with two generalized degrees of freedom (linear axial deformation, and the twist angle in relation to the longitudinal axis). Dependence of strength on the picture of wear is analyzed by means of statistical modeling of defects location in each section of the rope after processing of the received defectograms. Individual residual resource is defined by the change history of the current margin of safety (bearing capacity) of the guy lines in relation to maximum permissible minimum margin of safety (survivability) of partially worn-out structure. The example of calculation is given concerning the individual residual resource of fiveguy lines of the retransmitting mast according to the data of three inspections with a year interval. For the most intense rope it is shown that the strength calculation gives the conservative estimates of the resource, which will be referred to reliability margin. On the basis of the received results the recommendations are formulated on the contents of the conclusion about technical condition of the controlled guy lines and the actions of service personnel concerning further operation.
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