Research On Shear Links With Perforated Web Sections

Öz

In eccentirally-braced frames (EBFs), link-to-column connections and the structural elements outside of the links must resist the internal forces generated by fully yielded and strain-hardened links. Using slotted perforated web section concept in shear link may help to prevent difficulty in design of link-to-column connections and all other frame members by limiting the link capacity without loss of its stability. For this, a shear link beam with a section of W10×33 was selected and three different slot hole pattern were generated in its web to form three different specimens. Finite element models of these specimens were developed using ABAQUS software. Material of link beam was ASTM A992 steel. A series of analyses were performed under quasi-static cyclic loading to study the behavior of link beam with reduced web section. 10.6% of area reduction in the web section with different hole arrangements were investigated and the effect of slotted perforated web on shear links was examined. Finite element analyses have revealed that equally spaced 6×4mm slots in the web had stable hysteresis behavior whereas strength degredation was occured when equally spaced 3×8mm slots were used in the web. The results of this study indicate that using high number of slot holes may help to limit forces transmitting to the link-to-column connections and all other frame members.

Anahtar Kelimeler

• Steel structures,Eccentrically braced frame,Link beam

Gövdesi Boşluklu Bağ Kirişleri Üzerine Bir Araştırma

Öz

Dışmerkez çaprazlı çelik çerçeve sistemlerde, bağ kirişi-kolon birleşimleri, bağ kirişi dışında kalan kat kirişleri, kolonlar ve çaprazlar gibi çevre elemanlar bağ kirişinin plastikleşmesine karşı gelen iç kuvvetler altında boyutlandırılmaktadır. Özellikle bağ kirişlerinin kesme etkisi altında plastikleşmesi öngörülen sistemlerde, mekanizma durumunda çevre elemanlarda çok yüksek iç kuvvetler oluşmaktadır. Bağ kirişinin gövde enkesitinde stabilite kaybına yol açmayacak düzenleme ile boşluklar açılması bağ kirişinin plastikleşme kapasitesin düşürülmesini dolayısıyla çevre elamanların ve birleşimlerin tasarımında daha küçük iç kuvvetlerle çalışılmasını sağlayacaktır. Bu çalışmada, hazırlanan sonlu eleman modelinin doğrulanması amacıyla daha önce deneysel çalışması yapılmış ASTM A992 malzemeden imal edilmiş W10×33 enkesit profili bağ kirişi olarak seçilmiştir. ABAQUS sonlu eleman yazılımı ile gövde enkesit alanının 10.6% sına karşı gelecek şekilde üç farklı boşluk yerleşimi modellenmiştir. Çevrimsel yükleme altında boşluıklu bağ kirişi modellerinin analizleri gerçekleştirilerek davranışları incelenmiş, sonlu eleman analizlerinden elde edilen sonuçlar incelendiğinde gövde enkesitinde yerleştirilen boşluk sıklığının eleman davranışını önemli ölçüde etkilediği görülmüştür. Eşit aralıklı 3×8mm boşluk yerleşiminde elemanda yerel göçmeler meydana gelirken eşit aralıklı 6×4mm boşluk yerleşiminde kararlı bir çevrimsel davranış elde edilmiştir.

Anahtar Kelimeler

• Steel structures,Eccentrically braced frame Shear link,Reduced web

Kaynakça

1. AISC 341-16, (2016). Seismic provisions for structural steel buildings, American Institute of Steel Construction, Chicago, Illinois, USA.
2. Azad, K. and Topkaya, C. (2017). A review of research on steel eccentrically braced frames. Journal of Constructional Steel Research, 128, 53–73.
3. Chao, S. and Goel, S. (2006). Performance-based seismic design of eccentrically braced frames using target drift and yield mechanism as performance criteria. Engineering Journal, 3.
4. Engelhardt, M. D. and Popov, E. P. (1989). Behavior of long links in eccentrically braced frames. Earthquake Engineering Research Center. Report No: UCB/EERC-89/01. (January)
5. Hauksdottir, H. O. (2008). Application of the reduced beam section concept for improving the ductility of certain eccentrically braced frames. Ph.D. Thesis. University of Washington.
6. HKS, (2017). ABAQUS/Standard CAE, Hibbit Karlsson Sorenson Inc., Version 2017
7. Ji, X., Wang, Y., Ma, Q. and Okazaki, T. (2016). Cyclic behavior of very short steel shear links. Journal of Structural Engineering. 142(2), 1–10.
8. Malley, J. O. and Popov, E. P. (1983). Design considerations for shear links in eccentrically braced frames. Earthquake Engineering Research Center. Report No: UCB/EERC•83/24. (November)

9. Malley, J. O. and Popov, E. P. (1984). Shear links in eccentrically braced frames. Journal of Structural Engineering, 110(9), 2275–2295.
10. Okazaki, T., Arce, G., Ryu, H.-C. and Engelhardt, M. D. (2004). Recent research on link performance in steel eccentically braced frames. 13th World Conference on Earthquake Engineering. 1-6 August. Vancouver, B.C., Canada
11. Okazaki, T. (2004). Seismic performance of link-to-column connections in steel eccentrically braced frames. Ph.D. Thesis. The University of Texas.
12. Okazaki, T. and Engelhardt, M. D. (2006). Finite element simulation of link-to-column connections in steel eccentrically braced frames. 8th U.S. National Conference on Earthquake Engineering. 18-22 April. San Francisco, USA.
13. Okazaki, T., Engelhardt, M. D., Hong, J.-K., Uang, C. and Drolias, A. (2015). Improved link-to-column connections for steel eccentrically braced frames. Journal of Structural Engineering. 10(8), 1–8.
14. Prinz, G. S. and Richards, P. W. (2009). Eccentrically braced frame links with reduced web sections. Journal of Constructional Steel Research. 65(10–11), 1971–1978.
15. Richards, P. W. and Uang, C.-M. (2003). Development of testing protocol for short links in eccentrically braced frames. AISC. Report No: SSRP-2003/08.
16. Yiǧitsoy, G., Topkaya, C. and Okazaki, T. (2014). Stability of beams in steel eccentrically braced frames. Journal of Constructional Steel Research, 96, 14–25.