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- MakaleYalnız künye2022Scopus SJRQ1A Parametric Study on Earthquake-Damaged Square Hollow Section T-Joints under Fire Conditions
Ozyurt, E.
This study numerically investigated the elevated temperature resistance of earthquake-damaged square hollow section (SHS) T-joints subjected to brace axial compressive load. The residual stresses and deformations due to the earthquake were obtained from a pushover analysis. The extensive numerical simulations were analyzed using nonlinear finite-element software to examine the effects of the beta ratio, gamma ratio, damage level ((D) over cap), and initial applied load (n(f)) on the fire resistance of SHS T-joints after verification of the numerical simulations based on the available test results in the literature. The results indicated that the fire resistance of SHS T-joints with axial compressive load in the brace member decreased significantly due to the residual stresses and deformations from the earthquake. This situation worsened in all numerical models as the damage level increased. The reduction rate of the critical temperature at various damage rates was independent of the initially applied load ratio, but the loading rate directly affected the fire resistance of the joint regardless of the earthquake. As the beta ratio decreased, the yielded area at the brace-to-chord intersection region increased. Thus, the critical temperature of the joints at a constant damage level was inversely proportional to the beta ratio. Joints with a large gamma ratio had larger residual stresses and deformations than those of corresponding joints with a small. ratio. Therefore, the fire resistance of the joints after the earthquake decreased as the chord-wall thickness decreased. The critical temperature of the joints with either a large beta or gamma ratio was limited by the deformation limit at high damage levels. The fire resistance of the SHS T-joints after the earthquake decreased due to residual stresses and deformations. That effect increased even more in joints with high beta and. ratios. (C) 2022 American Society of Civil Engineers.
AtıfWoS8OpenAlex8İncele - MakaleYalnız künye2018Scopus SJRQ1Earthquake Performance of Reinforced-Concrete Shear-Wall Structure Using Nonlinear Methods
Çavdar, Ozlem; Çavdar, Ahmet; Bayraktar, Ender
In earthquake engineering, the performance-based design method is used to determine the expected performance level of structures under an earthquake effect. The level of performance is related to the damage situation that could occur in the structure after the earthquake. In performance-based structural design, it is predicted that more than one damage level can emerge under one earthquake effect. In this study, the seismic behavior of a reinforced-concrete shear-wall building that collapsed during the 2003 Bingol earthquake was investigated by nonlinear static analysis and nonlinear dynamic analysis. The selected reinforced-concrete shear-wall structure is located in Bingol, Turkey. Local code was considered for assessing a seismic performance evaluation of the selected reinforced-concrete shear-wall building. The performance goals of the reinforced-concrete shear-wall structure were evaluated by applying the pushover (incremental equivalent earthquake load) method and procedures of the code and nonlinear dynamic analysis. According to the code, the reinforced-concrete shear-wall building was not expected to satisfy life safety performance levels under a design earthquake. In this study, one collapsed building was selected in order to test the reliability and usability of performance analysis methods under different earthquakes.
AtıfWoS10OpenAlex19İncele - MakaleYalnız künye2016Scopus SJRQ2Nonlinear Earthquake Performance Evaluation of a Structure Collapsed during the Van, Turkey, Earthquake on October 23, 2011
Çavdar, Ozlem; Bayraktar, Alemdar
The paper investigates the structural performance of a seven-story reinforced concrete (RC) building that collapsed during the Van (Turkey) earthquake on October 23, 2011, using nonlinear static and dynamic methods. The selected RC building has two blocks and was designed according to the Turkish Earthquake Code (TEC) in 1975. The site investigation included sections and steel detailing and soil and concrete properties taken after the earthquake. The pushover and nonlinear time history analyses of the building were completed using the existing plan and test and observation data. It is concluded that the building collapses both analysis types. (C) 2015 American Society of Civil Engineers.
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