Deflections and periods of natural oscillations of systems of cross-farm from paired angles and tubular profiles at various support schemes

 

A.S.Marutyan, Cand. Tech. Sci., associate professor, branch of North Caucasus Federal University in Petigorsk, Russia;

A.G. Abovyan, Cand. Tech. Sci, associate professor of the department of Metal and wooden structures of Moscow State University of Civil Engineering (National Research University), Russia, Moscow

 

Abstract. The effectiveness of the use of cross-farm systems in the supporting structures of coatings (ceilings) of buildings and structures, ensuring an increase in their reliability and technical and economic characteristics, is noted. In the general number of cross systems, light metal constructions of complete delivery are distinguished, which are blocks (modules) of coatings and ceilings from Pyatigorsk-type cross trusses, which, despite the instability of the conjuncture, continue to be in demand. A technique for the approximate calculation of the basic periods of natural oscillations and deflections of such structures is given. The application of this calculation is shown on the example of the two-modification cross­farm systems (from twin angles and tubular profiles) on a square plan with various support schemes. In relation to these trusses, the design parameters of the construction mass coefficient are determined, taking into account the consumption of structural material for auxiliary elements. When comparing the obtained results with the data of finite element modeling, acceptable accuracy and sufficient prostate of approximate calculation for practical application at different stages of cross-sectional design were revealed. According to their technical and economic characteristics, cross trusses from tubular profiles are preferable.

Key words: cross-truss system, pair corners, rectangular pipes, coating structure, period of natural oscillations, deflection.