Optimization of truss lattices from profile pipes (bent-welded profiles)

The article presents a new method of manufacturing lattices with faceless assemblies for truss structures made of profile pipes (bent-welded profiles), tested on their triangular and diagonal systems including flat and cross modifications. Its efficiency and rationality are shown in nodes where the belt elements of square pipes differ in a rhombic arrangement relative to the plane of the structure, which are more preferably replaced by triangular and pentagonal profiles. The versatility of the manufacturing method ensures its relevance in structures made of tubular and rolled profiles, preserves the accepted layout of standardized trusses with faceless assemblies and flange connections. The regularity of the optimization calculation of the unification zones in relation to the core elements of the lattices with the determination of their design coefficients is given. A comparative calculation of the design coefficients and the averaged coeffi cients of the use of the core elements of the grid of square and rectangular profiles is carried out on the example of their implementation in the same semi-truss, when the number of unification zones coincides. The noticeable reduction in the structural material (steel) and the lowering of the construction height of the truss structure were revealed. The acceptable correctness of the approximate calculation method for its application in solving optimization and variant problems, as well as at different stages of the design of load-bearing structures, is confirmed.