Çaprazlı çelik çerçevelerin sismik performansı üzerine bazı değerlendirmeler / Some assessments on seismic performance of braced steel frames

1994 Northrige ve 1995 Kobe depremleri gosterdi ki, orta ve buyuk olcekte yer hareketine maruz kalan celik yapilarda, uygun cerceve geometrisi ve yeterli birlesim detaylari ortaya konmadigi zaman; sunek ve yuksek dayanim kapasitesine sahip oldugu bilinen celik yapilarin, sanildigi gibi deprem karsisinda yuksek performans seviyesi sergileyemedigi gorulmustur. Depreme dayanikli celik yapi tasariminda bu depremler, bir donum noktasi olmakla birlikte, yapisal celik sektorunde yeni arayislari ve yeni tasarim kriterlerinin belirlenmesine sebep olmustur. Yeni tasarim kriterlerinin belirlenmesine duyulan bu ihtiyaclar neticesinde son yillarda, celik yapilarin sismik performansi uzerine pek cok calisma yapildi. Bu calismalarin cogu sayisal calismalardir. Sayisal calismalar deneysel calismalarla desteklenmis ve ileri muhendislik programlari kullanilarak gerceklestirilmistir. Deneysel calismalar ise sayisal calismalara gore daha az sayida gerceklestirilmistir. Bu calismalarda, temel farkliliklar ya sayisal ve deneysel modelleme ya da kullanilan programlar ve deney duzenekleridir. Bu makale, celik yapilarin sismik performansi uzerine yapilan calismalarda karsilasilan sorunlari irdelemekte ve tartismaktadir. The 1994 Northridge and 1995 Kobe earthquakes showed that new technologies and structural configurations are needed to limit damage to steel structures subjected to moderate and large ground motions. In order to evaluate the behavior and seismic capacity of structures under earthquake effect traditionally, seismic design methods are insufficient. In recent years, many studies about seismic performance of steel frames have been carried out in the world. Most of these studies are numerical studies. Numerical studies carried out by making use of advanced computer programs and to be supported with experimental studies. Experimental studies, though few in number, are carried out as well. In these studies, main differences are both on the bases of numerical and experimental modeling or computer programs and experiment sets. This paper is investigate and discuss some problems which are made about studies of seismic performance of steel structures in last decade.