Browsing by Author "Kalkan, I."

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Citation - WoS: 1
Citation - Scopus: 1
Effects of the Location and Size of Web Openings on Shear Behavior of Clamped-Clamped Reinforced Concrete Beams
(Techno-Press, 2024) Aksoylu, C.; Özkiliç, Y.O.; Hakeem, I.Y.; Kalkan, I.
The present study pertains to the effects of variations in the location and size of drilled web openings on the behavior of fixed-fixed reinforced concrete (RC) beams. For this purpose, a reference bending beam with a transverse opening in each half span was tested to failure. Later, the same beam was modeled and analyzed with the help of finite element software using ABAQUS. Upon achieving close agreement between the experimental and numerical results, the location and size of the web opening were altered to uncover the effects of these factors on the shear strength and load-deflection behavior of RC beams. The experimental failure mode of the tested beam and the numerical results were also verified by theoretical calculations. In numerical analysis, when compared to the reference (D0) specimen, if the distance of the opening center from the support is 0 or h or 2h, reduction in load-bearing capacity of 1.5%-22.8% or 2.0%-11.3% or is 4.1%-40.7%. In other words, both the numerical analyses and theoretical calculations indicated that the beam behavior shifted from shear-controlled to flexure-controlled as the openings approached the supports. Furthermore, the deformation capacities, energy absorption values, and the ductilities of the beams with different opening diameters also increased with the decreasing distance of the opening from supports. Web compression failure was shown to be the predominant mode of failure of beams with large diameters due to the lack of sufficient material in the diagonal compression strut of the beam. The present study indicated that transverse openings with diameters, not exceeding about 1/3 of the entire beam depth, do not cause the premature shear failure of RC beams. Finally, shear damage should be prevented by placing special reinforcements in the areas where such gaps are opened. © 2024 Techno-Press, Ltd.
Influence of Overhang Length on Ltb Behavior of Compact Doubly-Symmetric Steel I-Beams
(Taylor and Francis Ltd., 2025) Basaran, B.; Aksoylu, C.; Kalkan, I.
The present study pertains to elaborating on the effects of overhang lengths beyond end supports on elastic and inelastic Lateral Torsional Buckling behaviour of doubly-symmetric steel I-beams. Finite element analyses were performed on compact sections to avoid the local (plate) buckling and beam distortions to interfere with the overall beam behaviour. Accuracy of the numerical analyses was verified with the help of existing experimental results. Subsequent to this verification, 120 beams with five different compact I-sections, four different overhang lengths, two different unbraced span lengths and three different sweep values were analysed. The numerical buckling moments of the beams with considerable overhangs were established to remain well below the respective estimates from AISC 360-16 formulation. The difference between the numerical and analytical values stems from the inability of the formula to reflect the lateral deflections of overhangs, i.e. predicating on full lateral restraint beyond unbraced spans. The study also indicated that flexural rigidities and moment capacities of beams increase with increasing overhang lengths. The increase in the buckling moment resistance in elastic and inelastic LTB were established to reach 11 and 16%, as the overhang-to-total length ratio increases from 0 to 0.30 for various sweep values. © 2025 Informa UK Limited, trading as Taylor & Francis Group.