Thesis Defense - Mesut Adalı (MSCE)

Mesut Adalı - M.Sc. Civil Engineering

Asst.Prof. Yiğit Özçelik – Advisor

Date: 18.01.2021

Time: 16:30

Location: This meeting will be held ONLINE. Please send an e-mail to gizem.bakir@ozyegin.edu.tr in order to participate in this defense.

SEISMIC PERFORMANCE ASSESSMENT OF STEEL CHEVRON BRACED FRAMES DESIGNED TO THE TURKISH BUILDING EARTHQUAKE CODE 2018

Thesis Committee:

Asst. Prof. Yiğit Özçelik , Özyeğin University

Asst. Prof. Bülent Erkmen, Özyeğin University

Asst. Prof. Bahadır Şadan, MEF University

Abstract:

Concentrically braced frames (CBFs) are commonly preferred in high seismicity areas to provide resistance against seismic loads. After significant damages were observed during the Northgate (1994) and Kobe (1995) earthquakes, CBFs are more popular owing to high stiffness and strength. Thus, research has been focused on behaviour of CBFs under severe earthquakes.

One of the configurations of CBFs is chevron (or inverted-V) braced frames (IVBFs) is also used in structures because of their architectural advantages. In chevron arrangement, while one of the story braces resist compression, the other one resist tension. Chevron CBFs need to undertake special consideration in design. Because, under a lateral loading when the compression brace buckles, the downward force emerges at the midspan of the beam. This unbalanced force can lead to formation of a plastic hinge at the midspan of the beam and collapse of the structure. To avoid such an undesirable mechanism, Turkish Building Earthquake Code 2018 (TBEC) that superseded Turkish Earthquake Code 2007 was introduced two yield mechanism. TBEC requires the structural members of IVBFs to be designed to resist the axial and flexural demands obtained from two yield mechanism.

In this study, firstly, a two-story IVBF was designed by considering new implications of TBEC such as yield mechanism, earthquake ground motion intensity levels and performance levels. Nonlinear response-history analyses were conducted to evaluate seismic performance of IVBF under ground motions. Secondly, incremental dynamic analysis (IDA) was performed on a two-story IVBF designed to TBEC. Capacity points were determined for each IDA curve and the collapse fragility curve of the frame was obtained. Collapse margin ratio (CMR) defined in FEMA P-695 was calculated.    

Bio: 

     Mesut Adali was born on February 27th, 1995 on Kırsehir, Turkey. After graduating high school, he started training for the Bachelor of Science degree in Civil Engineering at Yıldız Technical University in 2013 and gratuated in 2018 with high honor. He started his master's studies in Özyeğin University in 2018. His research is focused on the seismic evaluation of steel chevron braced frames, post-buckling behavior of steel braces. During his studies, he subsequently worked as a Teaching Assistant in the Civil Engineering Department of Özyeğin University. Currently, he is working as a structural design engineer at Ulker Consulting Engineers.