Browsing by Author "Özkiliç, YO"

Now showing 1 - 5 of 5
  • No Thumbnail Available
    Item
    Numerical validation on novel replaceable reduced beam section connections for moment-resisting frames
    Özkiliç, YO; Bozkurt, MB
    This study presents replaceable reduced beam sections with connection detail for MRFs under residual drift. The proposed detail includes end-plated mid-spliced reduced beam sections. Pursuant to this goal, the proposed detail has been investigated under cyclic loading protocol required by AISC 341-16 by using ABAQUS finite element program. Seismic response of the proposed connection detail was compared from PEEQ and Rupture Index standpoint. The obtained findings indicate that the proposed mid-spliced replaceable reduced beam section satisfies all requirements indicated by AISC 341-16.
  • No Thumbnail Available
    Item
    Mid-spliced end-plated replaceable links for eccentrically braced frames
    Özkiliç, YO; Bozkurt, MB; Topkaya, C
    Eccentrically braced frames (EBFs) can be re-used after a major seismic event by replacing the link members. Recent years have witnessed the development of numerous replaceable links. Among various details developed for this purpose, extended end-plated replaceable links are found to be the most efficient. The use of these links enables the engineer to minimize the size and the weight of the part to be replaced. In addition, the performance of end-plated links is similar to that of conventional links. Research reported to date has shown that end-plated links have disadvantages in terms of removal and replacement. Large axial forces can develop within the link member. Removal and replacement operations may require the use of hydraulic jacks to push the ends of the collector beams and the flame cutting of the links to gradually release the residual stresses and deformations. More important are the difficulties associated with link replacement under residual frame drifts. A novel detachable, replaceable link is proposed in this study which employs a splice connection at the mid-length of the link. The splice connection consists of channel sections welded to both parts of the replaceable link. The detail employed provides an erection tolerance which facilitates easy removal and enables replacement under residual frame drifts. Proof-of-concept testing of the proposed links was performed on 3 specimens where the type of force transfer in the splice connection was considered as the prime variable. All specimens failed at link rotation angles that were significantly higher than the link rotation angle required by AISC341 and demonstrated the potential of the proposed link concept. Complementary finite element parametric studies were conducted to validate the design procedure developed for the proposed replaceable link concept.
  • No Thumbnail Available
    Item
    Evaluation of seismic response factors for BRBFs using FEMA P695 methodology
    Özkiliç, YO; Bozkurt, MB; Topkaya, C
    This paper reports the details of a numerical study undertaken to evaluate seismic response factors for steel buckling-restrained braced frames (BRBFs) using the FEMA P695 methodology. In the United States, BRBFs are designed according to Minimum Design Loads for Buildings and Other Structures (ASCE 7) and the Seismic Provisions for Structural Steel Buildings (AISC 341). Twenty-four archetypes were designed according to the U.S. specifications and their behavior was assessed by making use of non-simulated collapse models. The interstory drift, brace axial strain and cumulative brace axial strain demands under collapse level ground motions were determined. The results obtained indicate that the current seismic response factors are adequate in terms of interstory drift and cumulative axial strain demands. On the other hand, large differences between the design level and collapse level axial strains were reported, which can result in undesirable brace behavior. Modified approaches were developed to estimate the axial strains for collapse level ground motions. These indude a modification to the deflection amplification factor and a modification to the AISC 341 requirements for expected brace deformations. The archetypes were redesigned using the proposed modifications and reevaluated using the FEMA P695 methodology. The results indicate that the proposed modifications result in axial strain demands that are in close agreement with the calculated demands. (C) 2018 Elsevier Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    Experimentally investigation of replaceable reduced beam section utilizing beam splice connection
    Özkiliç, YO; Bozkurt, MB
    This study presents a replaceable reduced beam section (R-RBS) located at the column end in moment resisting frames (MRFs). An end of the R-RBS is connected to column by using end-plate moment connection and the other end of that is connected to main beam with beam splice connection. Therefore, the RBS that is expected to yield under an earthquake can be easily replaceable. Geometry of the RBS and the thickness of the beam splice connection are the prime variables of this study. A total of eight experimental test was carried out to examine the seismic performance of the proposed R-RBS with the connection details. The results obtained from experimental studies demonstrated that plate sizes of the beam splice connection significantly affect the seismic performance of RBSs used in MRFs.
  • No Thumbnail Available
    Item
    Comparison of Turkish Steel Building Specifications, TS 648 and SDCCSS 2018
    Bozkurt, MB; Ergüt, A; Özkiliç, YO
    This study presents similarities and differences between Turkish Building Code for Steel Structures, which are TS 648 and SDCCSS (Specification for Design, Calculation and Construction of Steel Structures) in terms of the design of the members. Hot-rolled I-shaped steel sections for symmetrical and U-shaped steel sections (i.e., channels) for monosymmetric sections were elaborated in detail. The design strength of tension members under tensile load, compression members under axial load and flexural members under flexure and shear were examined separately. Connection details for tension members, slenderness for compression members and distance between lateral supports for flexural members were considered as prime variables. Analysis results revealed the design strength of the tension members where at least one of the cross-sectional parts is not connected to the connection plates, I-shaped compression members where a slenderness ratio is below 39 (.<39), U-shaped compression members and flexural members where Lb is between Lp and Lr (Lp