OPTIMIZATION OF TRUSS STRUCTURES WITH CHORDS OF PENTAGONAL PROFILE PIPES ISOSCELES AND EQUILATERAL

The article determines the specified values of optimal parameters of pentagonal profile pipes (bent-welded profiles), equally stable out of and within the truss structure. The efficiency and rationality of their use in chord elements are shown due to the functionality of the layout design of cross sections, including one flange (horizontal face), a pair of walls (vertical faces) and a pair of inclined faces symmetrically arranged to the vertical at angles of 45° in the first modification (equilateral) and 60° in the second modification (isosceles). Both modifications disclose the certain prospect for high functional layout design in the updated faceless nodes typical for truss structures made of tubular profiles. The article gives the comparative calculation of the design coefficients and the averaged coefficients of the use of chord core elements made of pentagonal profiles with the example of their implementation in the same semi-truss, when the number of unification zones coincides. A noticeable decrease in the mass (weight) and reduction of the structural material (steel) of the chords and, as a consequence, the entire structure was revealed by the increased values of static (geometric) characteristics of the design sections. The acceptable correctness of the approximate calculation method is confirmed for its application in solving optimization and variant problems as well as at different stages of load-bearing structures’ design.