Շինարարական կոնստրուկցիաների լարվածային վիճակի որոշման հաշվարկային մեթոդիկա

Abstract

The behavior of structural elements and lifting equipment (pipe joints, weld sections, transmission nodes, etc.) under combined cyclic bending and torsion is considered. It has been shown that in similar studies, this stress state was evaluated only based on strength criteria, the parameters of which, regardless of the service life of the structures and deviations in the physical and mechanical data of the elements, were taken as constant values that only correspond to the median fatigue limits. Structures are poorly studied based on the durability criterion, which has become a primary task in reducing material intensity in recent decades due to the growth in construction volumes. Under single and combined factor influences (element geometry, stress concentration, loading mode, technological operations, etc.), the necessity of simultaneously addressing strength and durability problems is considered. By jointly solving the equations of fatigue lines for experimental samples, functional connections between the relative coefficients of strength and durability are established, which are also variable and probabilistic in nature. In logarithmic coordinate systems, the specified functions are presented for single and complex effects of factors, with the help of which, for any point of the fatigue zone coordinates, it is possible to obtain the values ​​of the coefficients in the interval of non-destruction probabilities of 10.0...99.9% for their use in design calculations for strength and durability.

.