Browsing by Author "Kalkan, Ilker"

Now showing 1 - 2 of 2

Effect of Stirrup Spacing and Recycled Steel Wires on the Shear and Energy Dissipation of Pultruded GFRP Hybrid Beams
(Sage Publications Ltd, 2025) Ozkilic, Yasin Onuralp; Kalkan, Ilker; Aksoylu, Ceyhun; Madenci, Emrah; Umiye, Osman Ahmed; Althaqafi, Essam; Beskopylny, Alexey N.
The contribution of Recycled Steel Wires (RSW) to the shear strength and behavior of pultruded glass fiber reinforced polymer (P-GFRP) hybrid composite beams with reinforced concrete infill, denoted as P-GFRP beams, was investigated experimentally and analytically in the current study. A total of six specimens with varying RSW ratio and stirrup spacing of the reinforced concrete (RC) core and a fixed shear span-to-beam depth ratio were tested to failure. The addition of RSW to concrete was established to have greater contribution to the beam strength with increasing stirrup spacing, that is, decreasing transverse reinforcement ratio. The contribution of RSW to energy dissipation capacity was found to be more pronounced in the elastic range of beam response as compared to the inelastic range. The theoretical calculations indicated that the RC core prevented the P-GFRP encasement from complete failure due to shear-induced material rupture at the initial stages of loading. By maintaining their integrity, the reinforced concrete-filled box beams (RCFB) were able to resist loading until complete failure associated with flexure-induced material rupture and web compression buckling. A strut-and-tie model providing accurate strength estimates for P-GFRP beams was also proposed.
Citation - WoS: 4
Citation - Scopus: 4
Lateral Torsional Buckling of Doubly-Symmetric Steel Cellular I-Beams
(Techno-Press, 2023) Ertenli, Mehmet Fethi; Erdal, Erdal; Büyükkaragöz, Alper; Kalkan, Ilker; Aksoylu, Ceyhun; Özkiliç, Yasin Onuralp
The absence of an important portion of the web plate in steel beams with multiple circular perforations, cellular beams, causes the web plate to undergo distortions prior to and during lateral torsional buckling (LTB). The conventional LTB equations in the codes and literature underestimate the buckling moments of cellular beams due to web distortions. The present study is an attempt to develop analytical methods for estimating the elastic buckling moments of cellular beams. The proposed methods rely on the reductions in the torsional and warping rigidities of the beams due to web distortions and the reductions in the weak-axis bending and torsional rigidities due to the presence of web openings. To test the accuracy of the analytical estimates from proposed solutions, a total of 114 finite element analyses were conducted for six different standard IPEO sections and varying unbraced lengths within the elastic limits. These analyses clearly indicated that the LTB solutions in the AISC 360-16 and AS4100:2020 codes overestimate the buckling loads of cellular beams within elastic limits, particularly at shorter span lengths. The LDB solutions in the literature and the Eurocode 3 LTB solution, on the other hand, provided conservative buckling moment estimates along the entire range of elastic buckling.