PSI - Issue 81

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ScienceDirect

Procedia Structural Integrity 81 (2026) 177–183

© 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of DMDP 2025 organizers Keywords: goal function, optimal design, steel I-beams, production constraints, technological constraints. 1. Introduction Optimization of structures has been a pressing problem in construction for decades (Bazhenov et al. (1999)). In the general case, the mathematical formulation of optimization problems consists in finding the physical and geometric parameters of the constructive form. Local optima – are standard for minimax optimization problems, and can form the so- called “Pareto set” (or “set of optimal alternatives”), when the value of each individual criterion describing the state of the system cannot be improved without worsening the situation of other elements. However, to find a truly economical solution, it is necessary to find a global optimum. “Global” means that it is valid for the entire set of solution options, and local means that it is valid only in a certain lo cality. A goal function can have several local maxima and minima. However, there can be only one global maximum and minimum (Chorney and Chorney (2005)). The problem of finding the global optimum is relevant primarily when solving problems of optimizing multimodal goal functions, which are manifested in the problems of optimizing building structures (Bilyk (2014)). With algorithmic objective functions that are discrete, multimodal, nonlinear, partially separable, and algorithmic, modern evolutionary methods for determining the optimal cross-section (swarm, genetic, ant, simulated annealing, etc.) (Tiago et al. (2021); Burke et al. (2006)) do not provide a full guarantee of convergence and achieving a global optimum. Another pressing Abstract Optimization of steel structures is an actual problem in construction. During the full-scale war unleashed by russia against Ukraine, lean design is an urgent need, in particular for critical national infrastructure protection tasks. A new algorithmic optimization method is proposed, which is called the directed selection method, and is a modification of the exhaustive search method. The proposed method takes into account production, technological and constructive constraints. The implementation of the method is shown on the example of finding the optimal solution for I-beams composed of steel sheets. Practical solutions to the problem of optimal selection of structures for engineering protection of critical national infrastructure facilities have shown the cost-effectiveness of the resulting steel I-beam sections compared to existing methods. The main advantages of the proposed method are the guaranteed accessibility to the global optimum rather than local optima and the absence of the need to rework the obtained sections for real design and construction conditions, since these conditions are already accounted for by constraints that reduce the feasible solution region. VIII International Conference “In - service Damage of Materials: Diagnostics and Prediction“ (DMDP 2025) New method of optimal selection of welded steel I-beams considering technological and production constraints Artem Bilyk* a Kyiv National University of Construction and Architecture, Povitroflotskyi Ave nue 31, 03680 Kyiv, Ukraine

* Corresponding author. Tel.: +38-067-196-77-86; fax: +0-000-000-0000 . E-mail address: bilyk_as@ukr.net

2452-3216 © 2026 The Authors. Copy from the contract: Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of DMDP 2025 organizers 10.1016/j.prostr.2026.03.031