Vibroengineering Procedia

Vibroengineering Procedia, Vol. 62, 2026, p. 710-716.Aleksey Bondarenko, Kuvandik Lesov, Talgat Salakhov, Ding Haibo, Mukhamedali Kenjaliyev, Murat AlimkulovThis paper investigates the stress-strain behavior of rail fastening systems in railway turnouts subjected to non-uniform stiffness distribution and cyclic axial wheel loading. Unlike conventional track sections, turnout fastening units exhibit structural asymmetry and complex load transfer mechanisms that significantly influence stress evolution and deformation response. A three-dimensional finite element model was developed to analyze the behavior of switch slide chairs under loading applied separately to the stock rail and the switch rail. The analysis determined maximum deflections of 4 and 5 mm for the stock-rail and switch-rail loading cases, respectively, and identified critical stress states from +200 to –433 MPa that may contribute to fatigue-related damage under repeated service conditions. The results demonstrate that under-rail pad stiffness substantially affects stress redistribution and the durability of fastening nodes. Based on these findings, recommendations are proposed for refining stiffness parameters to enhance the reliability and service life of railway turnouts.

Vibroengineering Procedia, Vol. 62, 2026, p. 610-615.Sattar Kholmirzaev, Akmaljon Akhmedov, Sobirjon Razzakov, Abdurasul Martazaev, Asalkhon JuraevaThis paper provides a numerical analysis of reinforced concrete and fiber-reinforced concrete beams under a static loading using ANSYS Mechanical. The chief aim is to compare the stress-strain condition, crack formation, deformation behavior, and load-bearing ability of the ordinary reinforced concrete beams with beams reinforced with steel and basalt fibers. The three-dimensional finite element models have been developed with the consideration of the real beam geometry, nonlinearity of the material behavior, reinforcement action, and the boundary conditions. It was a model of concrete and fiber-reinforced concrete where the proper physical and mechanical properties were used, and the reinforcement was described with the help of an ideal elastic-plastic model. The quantitative findings indicate that fiber reinforcement enhances crack resistance, narrows crack width, and augments ultimate bending capacity of the beams. One of the series studied, a specimen with 100 percent steel fiber reinforcement, gave a high bending moment of 21.42 kN·m, as compared to 15.86 kN·m with the normal reinforced concrete beam, or a 35 percent increase. The findings support the idea that the dispersed fiber reinforcement can play an important role in promoting the structural performance of reinforced concrete beams and can be successfully implemented in engineering practice.

Vibroengineering Procedia, Vol. 62, 2026, p. 423-429.Ulugbek Abdullaev, Erkin Kaxarov, Xiaokang Zhao, Wang ZhiyuThis article investigates the influence of a new-generation high-performance superplasticizer, developed by the Arment Construction Chemicals Company, on the properties of fresh and hardened concrete. The innovative admixture is characterized by a synergistic polymix formulation of advanced polymers, combined with a proprietary binary filler system. The primary objective of the research is to evaluate the efficacy of this composite chemical in enhancing workability, mechanical strength, and durability beyond the capabilities of conventional superplasticizers. The experimental methodology involved preparing concrete mixtures with varying dosages of the new superplasticizer, which were compared against control mixes and those containing traditional water-reducers. The fresh properties assessed included slump, slump retention over time, and setting time. For the hardened state, compressive and flexural strength tests were conducted at different curing ages, alongside an analysis of durability indicators such as water permeability and resistance to chemical attack.

Vibroengineering Procedia, Vol. 62, 2026, p. 126-133.Ziyovuddin Rakhimjonov, Fakhriddin Zokirov, Artanti LintangBridges located in seismic regions are subjected to strong dynamic actions that may cause excessive bending moments, shear forces, and displacements in piers and foundations. In conventional seismic design, the bridge span is commonly treated as a rigid inertial mass transmitting earthquake-induced forces to the supports, while the beneficial dynamic interaction between the span and the pier is not fully utilized. This study proposes a seismic protection approach in which the bridge span is considered as a tuned dynamic component capable of reducing the response of the pier. A coupled two-degree-of-freedom mathematical model of the span–pier system subjected to base excitation is developed, and a parametric analysis is carried out to determine rational stiffness and damping parameters of the span–support connection. The optimization procedure is performed under practical displacement constraints imposed by the deformation joints. The results show that the most efficient vibration reduction is achieved for properly selected stiffness and damping ratios, with the practical stiffness range lying near f= 0.12 and f= 0.2-0.3, depending on the adopted damping level. For the considered bridge, the permissible relative displacement of the span with respect to the support is 6-12 cm, and the bending moments in the pier can be reduced by up to 2.33 times compared with the conventional seismic design approach. The proposed method improves the seismic reliability of reinforced concrete bridge systems without introducing additional external damping masses.

Vibroengineering Procedia, Vol. 62, 2026, p. 134-139.Gayrat Khakimov, Khadicha Abduraimova, Sayyora Tadjikhodjaeva, Makhsudali Qambarov, Abdukayum Berdimurodov, Ganisher MalikovThis article presents the results of laboratory experiments investigating the influence of dynamic vibration frequency on changes in the cohesion and deformation of moistened loess soil. It is known that as the intensity of oscillations increases, the strength characteristics of moistened loess and other weakly cohesive soils decrease. This is primarily due to a reduction in cohesion, which in turn leads to an increase in soil deformation. It should also be noted that the vibration frequency plays the most significant role in structural degradation, cohesion reduction, and increased soil deformation. Analysis of the consequences of many destructive earthquakes shows that high-frequency earthquakes are the most dangerous for moistened loess and other weakly cohesive soils in terms of disrupting their dynamic stability.