Investigation of the effects of vertical link beam length on steel structures residual displacement

Author
A. Bathaei
University of Tehran
Abstract
There is a debate among earthquake engineers that the structural and non-structural damages initially occur due to lateral loads caused by earthquake excitation. American provisions, including FEMA356 estimates structural performance by means of maximum deformation demand. However, in addition to the maximum deformation, residual displacement plays an important role in structural performance. Amplitude of residual displacement is an important parameter in technically and economically determining rehabilitation of damaged structures for resisting aftershocks. In this study, residual displacements of a five-story steel frame is designed with vertical link beam as well as the effect of vertical link beam length have been investigated. For vertical link beam, the IPE sections with typical steel is considered, instead of using boxes and H-shaped cross-section.The IPE section has some advantages than box section such as lower cost, easier installation and replacement. The Vertical link beams with IPE cross-section has been studied in 5 separate models with length of 20, 25, 30, 35 and 40 centimeters. In this paper, experimental results of a frame model with vertical link beam tested in structural laboratory of Building and Housing Research Center (BHRC) has been used for verification of numerical model. As one of the fastest nonlinear softwares, OpenSees (Open System for earthquake engineering simulation) has been used for structural modeling. The steel material that has been used in this model is uniaxial material steel 02. In the following, seven near field and seven far field earthquake acceleration time histories that scaled by 2800 standard, are used analysis of five-story and five-bay structure with chevron bracing system. According to the seismic design of structures if ductile elements is used in a structure, then beams and columns should remain elastic during earthquake, while ductile elements dissipate input energy by nonlinear behavior of ductile members. By considering of the results, the vertical link beam with length of 20 and 25 centimeter for far field earthquakes and 20 centimeter for near field earthquakes have the best performance compare to the other cases. The Bam earthquake is selected to investigate of hysteresis diagram of the vertical link beam energy dissipation. The results for near field earthquake like the Bam earthquake show that link beam with length of 40 centimeter with moment behavior, has low energy dissipation capability. Furthermore, the vertical link beam with 40 centimeter length causes more residual displacement and yielding. By considering the station with equal 104.28 km distance from center of earthquake can use the Bam record as a far field earthquake. In this case link beams with more than 25 centimeter length have more fluxing. However, the link beams with length of 20 and 25 centimeter have better seismic performance. Considering the RMS (Root Mean Square) parameter as a controller criterion the vertical link beam with length of 20 centimeter is more suitable for near and far field earthquakes. Considering the seismic performance parameters of vertical link beam like appropriate stiffness, high stability, energy dissipation capability, appropriate control of maximum response of structure and less residual displacement, the vertical link beam with length of 20 centimeter has the best seismic performance for near and far field earthquakes compare to the other cases.

Keywords

[1] Soong, T.T. and Costantinou, M.C. 2014 Passive and active structural vibration control in civil engineering, Springer, USA.
[2] De Matteis, G., Formisano, A., Panico, S. and Mazzolani, F.M. 2008 Numerical and experimental analysis of pure aluminum shear panels with welded stiffeners. Computers & Structures, 86(6), 545-555.
[3] Tanaka, K. and Sasaki, Y. 2000 Hysteretic performance of shear panel dampers of ultra-low-yield-strength steel for seismic response control of buildings. 12WCEE (CD-Rom). Aucklan, NZ.
[4] Nakashima, M., Iwai, S., Iwata, M., Takeuchi, T., Konomi, S., Akazawa, T., Saburi, K. 1994 Energy dissipation behavior of shear panels made of low yield steel. Earthquake engineering & structural dynamics, 23(12): 1299-1313.
[5] Dusicka, P., Itani, A.M. and Buckle, I.G. 2004 Evaluation of conventional and specialty steels in shear link hysteretic energy dissipaters. Proceedings of 13th World Conference on Earthquake Engineering, Vancouver, Canada.
[6] Dusicka, P. and Itani, A. 2002 Behavior of built-up shear links under large cyclic deformations. Proceedings of the 2002 Annual Meeting of the Structural Stability Research Council. Structural Stability Research Council, Gainesville, FL.
[7] Arce, G., Okazaki, T. and Engelhardt. M. 2003 Experimental behavior of shear and flexural yielding links of ASTM A992 steel.Proceedings of the 4th Intl. Specialty Conference on Behavior of Steel Structures in Seismic Areas, Stessa, Naples, Italy.
[8] McDaniel, C.C., Uang, C.-M. and Seible, F. 2003 Cyclic testing of built-up steel shear links for the new bay bridge. Journal of Structural Engineering, 129(6): 801-809.
[9] Galvez, P. 2004 Investigation of Factors Affecting Web Fractures in Shear Links, M.Sc. thesis, Univ. of  Texas at Austin, Tex., USA.
[10] Buckle, I., Dusicka, P. and Itani, A. 2005 Development of built-up shear links as energy dissipaters for the seismic protection of long-span bridges, Bridge Structures, 1(1): 19-27.
[11] Chao, S.-H., Khandelwal, K. and El-Tawil, S. 2006 Ductile web fracture initiation in steel shear links. Journal of structural engineering, 132(8): 1192-1200.
[12] Okazaki, T. and Engelhardt, M. D. 2007 Cyclic Loading Behavior of EBF Links Constructed of ASTM A992 Steel, J. of Constructional Steel Research. 63(6): 751-765.
 [13] Berman, J. W. and Bruneau, M. 2007 Experimental and analytical investigation of tubular links for eccentrically braced frames, J. Engineering Structures, 29: 1929-1938.
[14] Chan, R. W. K., Albermani, F. and Williams, M. S. 2009 Evaluation of yielding shear panel device for passive energy dissipation, J. Const. Steel Research, 65(2), 260-268.
 [15] Mahin, S.A. and Bertero, V.V. 1981 An evaluation of inelastic seismic design spectra. Journal of the Structural Division, 107(9): 1777-1795.
[16] MacRae, G.A. and Kawashima, K. 1997 Post‐earthquake residual displacements of bilinear oscillators. Earthquake engineering & structural dynamics, 26(7): 701-716.
[17] Kawashima K, MacRae GA, Hoshikuma J, Nagaya K. 1998 Residual placement response spectrum. Journal of Structural engineering(ASCE), 124(5):523 –530.
[18] Pampanin, S., Christopoulos, C. and Priestley, M. 2002 Residual deformations in the performance-seismic assessment of frame structures, Research Report No. ROSE-2002.
[19] Engelhardt, M.D and Popov, E.P. 1992 Experimental performance of long links in eccentrically braced frames. Journal of Structural Engineering, 118(11): 3067-3088.
 
[20] Zahrai, S.M. and Moslehi Tabar, A. 2013 Analytical study on cyclic behavior of chevron braced frames with shear panel system considering post-yield deformation, Canadian Journal of Civil Engineering, 40(7): 633-643.
[21] Zahrai, S.M. and Parsa, A. 2015 Effect of Flange Width of Vertical Link Beam on Cyclic Behavior of Chevron Braced Steel Frames. Journal of Seismology and Earthquake Engineering, 17(4): 281-292.
 [22] American Institute of Steel Construction, AISC 2002 Load and resistance factor design, Manual of Steel Construction.
 [23] International building code, IBC2003, Whitier, California.
 [24] Boukamp, J. G. and Vetr, M. G. 1994 Design of Eccentrically Braced Test Frame With Vertical Shear Link Proceedings of the 2nd Int. Con. On Earthquake Resistant Construction and Design, Berlin.
 [25] Recommended Lateral Force Requirements and Tentative Commentary 1988 Seismology Committee, Structural Engineers Association of California.
[26] Zahrai, S. and Mahroozadeh, Y. Experimental study of using vertical link beam to improve seismic performance of steel buildings. Civil Engineering Infrastructures Journal, 2010. 44(3): 379-393.
[27] Mazzoni, S., McKenna, F., Scott, M.H. and Fenves, G.L. 2006 OpenSees command language manual. Pacific  Earthquake Engineering Research (PEER) Center.
[28] PEER. Open system for earthquake engineering simulation (OpenSees). Version 2.4.0. Berkeley: Pacific Earthquake Eng. Research Center, Univ. of California; 2005. http://opensees.berkeley.edu/.
[29] Building & Housing Research Center 2014 Standard No. 2800, Iranian code of practice for seismic resistant design of buildings. BHRC Publication No. S. 253.
Modares Civil Engineering journal
Volume 17, Issue 3
September and October 2017
Pages 47-60