Vladimir State University named after Alexander and Nikolay Stoletovs (Vladimir, Russia)¹ ; National Research Moscow State University of Civil Engineering (Moscow, Russia)²

M. V. Lukin, Cand. Eng., Associate Prof., Dept. of Building Structures¹, Associate Prof., Dept. of Architectural and Construction Design and Environmental Physics², e-mail: lukin_mikhail_22@mail.ru

Vladimir State University named after Alexander and Nikolay Stoletovs (Vladimir, Russia)
S. I. Roshchina, Dr. Eng., Prof., Head of the Dept. of Building Structures, e-mail: rsi3@mail.ru
E. S. Prusov, Dr. Eng., Prof., Dept. of Technology of Functional and Structural Materials, e-mail: eprusov@mail.ru

Vladimir State University named after Alexander and Nikolay Stoletovs (Vladimir, Russia)¹ ; Moscow Polytechnic University (Moscow, Russia)² ; National University of Science and Technology MISIS (Moscow, Russia)³
V. B. Deev*, Dr. Eng., Prof., Chief Researcher¹, Head of the Dept. of Equipment and Technology of Welding Production², Prof. of the Dept. of Metal Forming³, e-mail: deev.vb@mail.ru

*Corresponding author

One of the key challenges in contemporary construction and mechanical engineering is the development of metallic products and structures with enhanced performance characteristics while simultaneously reducing their material consumption and overall cost. A promising approach to addressing this challenge lies in the design and implementation of bi-steel structures, which rationally combine steels of different strength grades. In the present study, a comprehensive numerical analysis of the stress–strain state of bi-steel roof trusses with an 18 m span (chords made of steel S345, web members made of steel S255) was performed using the finite element method within the LIRA 10.12 software package. In addition, a comparative evaluation of their techno-economic efficiency was carried out relative to conventional mono-steel structures (steel S255). The analysis included the distribution of internal forces and load-bearing capacity in both bi-steel and mono-steel trusses. The numerical simulations confirmed that the adoption of a bi-steel configuration does not alter the fundamental structural behavior of the truss but enables a redistribution of stresses and improves overall structural reliability. Section optimization demonstrated that transitioning to the bi-steel design reduces the total truss weight by 25.1 % while maintaining its load-bearing capacity, thereby lowering transportation and on-site assembly costs. The techno-economic assessment further revealed associated reductions of 11.4 % in material costs, 16.7 % in production labor intensity, and 12.3 % in the final factory cost of the structure. The results obtained provide a foundation for further investigations, including experimental validation, studies of fatigue performance, and the development of regulatory guidelines for the application of bisteel structures.

The research was carried out within the state assignment in the field of scientific activity of the Ministry of Science and Higher Education of the Russian Federation (theme FZUN-2024-0004, state assignment of the VlSU).

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