STRESS-STRAIN STATE OF THE ELEVATOR WORKING TOWER FLOOR UNDER DYNAMIC LOADS

Abstract

Abstract. This paper examines the performance and stability of steel–concrete composite systems used in the working towers of grain elevator facilities, subjected to dynamic effects originating from grain cleaning equipment. The research centers on evaluating the structural response of elevator towers with separator floors formed either from steel-only frameworks or composite slabs incorporating concrete and profiled sheeting. Particular attention is given to resonance susceptibility and methods to enhance structural integrity under operational conditions. Purpose. The aim of the study is to analyze and compare the dynamic performance of different flooring systems in grain elevator towers – steel-only structures versus steel–concrete composite slabs – and to assess their susceptibility to resonance caused by grain cleaning equipment. Methodology. The study employed modal analysis of two flooring configurations using computational modeling tools. Natural frequencies and corresponding mode shapes were determined via LIRA-FEM for both static and dynamic analysis. Autodesk Revit was used to develop the structural models. Resonance risk was evaluated by comparing computed natural frequencies with the known 5 Hz operational frequency of grain cleaning machinery. Results. The analysis revealed that composite floor systems using profiled steel decking and concrete slabs significantly reduce vibration intensity compared to steelonly floors. Variations in concrete slab thickness and shear connector dimensions were tested, resulting in improved dynamic behavior and structural stability. The natural frequencies of both systems were benchmarked to evaluate resonance potential. Composite floors showed better alignment with safety requirements and machine stability under dynamic loads. Scientific novelty. The study introduces the application of steel–concrete composite floor systems with profiled decking as permanent formwork in grain elevator towers, highlighting their effectiveness in minimizing resonance effects. The research presents an original configuration that enhances structural performance and operational safety, laying the groundwork for further optimization of slab parameters in future investigations. Practical significance. The results of this research can be used to improve the design of grain elevator tower floors by selecting appropriate composite configurations. The tested systems showed better vibration damping and structural stability, which contributes to safer and more reliable operation of grain cleaning equipment. These findings support engineers in making informed decisions when designing dynamically loaded agricultural facilities.