There is a tendency to reduce weight of load-bearing metal structures being developed and successfully realized in modern building construction. This idea serves as a basis for a whole scientific direction, named Development and application of light steel thin-walled structures (LSTS). Among them, LTST built with pop-rivets and thread-cutting screws are most widespread due to their simplicity and relative cheapness This paper presents numerical studies of LSTS joint assembly units built with screws and their load bearing capacity. The peculiarity of these units consists in misalignment of joint elements. The calculation was performed in the SolidWorks Simulation System. The modeled node is a threedimensional assembly consisting of solid components. The results of the study are as follows: 1) thin-walled profiles have a significant sensitivity to eccentricity; 2) it is unacceptable to disregard eccentricities for thin-walled profiles and their joint connections; 3) eccentricities should be compensated by measures to improve reliability in joint connections design.
Breeding work in the Michurinsk State Agrarian University (MSAU) is based on one of the eff ective strategies for producing high-quality planting material for establishment of intensive perennial fruit plantations – the use of apple varieties and clone stocks that are highly resistant to extreme factors and immune to diseases. As a result of many years of breeding work, the MSAU is the originator of 24 forms of clonal stocks (out of 46 forms allowed for cultivation in the Russian Federation) and the patent holder of 8 stocks. In 2018, 4 apple clonal rootstocks (70-20-20, 70-20-21, 71-7-22, 75- 1-62) were included in the State Register of Breeding Achievements admitted to cultivation on the territory of the Russian Federation. The main requirements for apple stocks for intensive orchards are high resistance to major environmental factors; suitability for intensive types of orchards; increased resistance to pathogens; good ability to vegetative propagation; lack of root shoots in the orchard; increase of productivity, early fruited varieties, quality of fruits. The advantages of planting material of apple trees on weak clonal rootstocks of the MSAU breeding are established: high compatibility of rootstocks with the best zoned and promising apple varieties; high frost resistance and winter hardiness of the root system, withstanding up to -16 °С – there are no foreign analogues on this basis; high resistance of stocks to the bacterial burn (unlike most foreign stocks); accelerated entry into fruiting, the onset of the period of commodity bearing fruit in the orchard on the 3rd ... 5th year; high productivity of commercial apple plantings in the conditions of Central Russia – an average of 25 to 40-50 tons / ha. For widespread introduction into production, the most studied clonal stocks of the MSAU breeding are recommended in Russia and in many countries of the world: the Paradizka Budagovsky (dwarf), 62-396 (half-dwarf), 54-118 (medium-sized). To increase the productivity and the resistance of plants and the eff ectiveness of Russian horticulture as a whole, it is necessary to create mother nurseries of apple rootstocks, free from harmful viral infections (repositories).
The concept of a managing system for biological and production processes in horticulture based on digital and intelligent technologies is formulated, which involves the development of horticultural technological systems at the level of the plant organism (molecular, genomic, cellular and tissue), at the level of the agroecosystem and at the branch level. For the collection, transmission, accumulation, storage and conversion of information in the form of feedback, it is proposed to use the technology of artificial neural networks. The existing technical capabilities allow, using data from all stages of horticulture, using digital parameters, to formulate a concept of risk control and optimization of technological processes based on the tasks solved by the technology of artificial neural networks. A system of control modules has been elaborated in the technological chain of production, preservation and sale of horticultural products, which allows differentiating information coming to the decision-making system.
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