Optimal Stiffeners Spacing for Intermediate Link in Eccentrically Braced Frame to Increase Energy Dissipation

Document Type : Research Article

Authors

Department of Civil Engineering, University of Isfahan, Isfahan, Iran

Abstract

In general, the behavior of an eccentrically braced frames (EBF) is dependent on the link member characteristics. An efficient link is designed ductile enough to dissipate energy and to prevent the collapse of the frame. Since the link member is reinforced with stiffeners, in order to improve its ductility and plastic deformation capacity, the details of stiffeners design shall be considered more precisely. The existing relationships for web stiffeners spacing in the provisions are based on the behavior of short links with pure shear, while these relationships are applied for intermediate links with shear-bending behavior as well, without any modification. Recent studies have shown the non-conservative stiffeners spacing for some intermediate links. In this study, an optimization algorithm is presented to find the best arrangement of the intermediate link stiffeners. The objective function is the plastic dissipated energy by link before failure and the design variables are locations of stiffeners. The link is simulated under static cyclic loads with finite element software ABAQUS. The heuristic optimization algorithm has been coded in the MATLAB software to find the optimum solutions. The results show that the dissipated energy before failure can be improved significantly by modification of stiffeners spacing.

Highlights

[1] A. Daneshmand, B.H. Hashemi, Performance of intermediate and long links in eccentrically braced frames, Journal of Constructional Steel Research, 70 (2012) 167-176.

[2] T. Okazaki, M.D. Engelhardt, Cyclic loading behavior of EBF links constructed of AStM A992 steel, Journal of constructional steel Research, 63(6) (2007) 751-765.

[3] P.W. Richards, Cyclic stability and capacity design of steel eccentrically braced frames, University of California, San Diego, 2004.

[4] P. Gálvez, Investigation of factors affecting web fractures in shear links, University of Texas at Austin, 2004.

[5] B. Chegeni, A. Mohebkhah, Rotation capacity improvement of long link beams in eccentrically braced frames, Scientia Iranica. Transaction A, Civil Engineering, 21(3) (2014) 516.

[6] N.D. Lagaros, L.D. Psarras, M. Papadrakakis, G. Panagiotou, Optimum design of steel structures with web openings, Engineering Structures, 30(9) (2008) 2528- 2537.

[7] M. Ohsaki, T. Nakajima, Optimization of link member of eccentrically braced frames for maximum energy dissipation, Journal of Constructional Steel Research, 75 (2012) 38-44.

[8] G. Arce, Impact of higher strength steels on local buckling and overstrength of links in eccentrically braced frames, University of Texas at Austin, 2002.

[9] K. Kasai, E.P. Popov, Cyclic web buckling control for shear link beams, Journal of Structural Engineering, 112(3) (1986) 505-523.

[10] ABAQUS, Dassault Systémes Simulia Corp., in, 2014.

[11] H. Amiri, A. Aghakouchak, S. Shahbeyk, M. Engelhardt, Finite element simulation of ultra low cycle fatigue cracking in steel structures, Journal of Constructional Steel Research, 89 (2013) 175-184.

[12] J.R. Rice, D.M. Tracey, On the ductile enlargement of voids in triaxial stress fields*, Journal of the Mechanics and Physics of Solids, 17(3) (1969) 201-217.

[13] A.M. Kanvinde, Micromechanical simulation of earthquake-induced fracture in steel structures, 2004.

[14] E. Kaufmann, B. Metrovich, A. Pense, Characterization of cyclic inelastic strain behavior on properties of A572 Gr. 50 and A913 Gr. 50 rolled sections, (2001).

[15] R. Eberhart, J. Kennedy, A new optimizer using particle swarm theory, in: Micro Machine and Human Science, 1995. MHS’95., Proceedings of the Sixth International Symposium on, IEEE, 1995, pp. 39-43.

Keywords


[1] A. Daneshmand, B.H. Hashemi, Performance of intermediate and long links in eccentrically braced frames, Journal of Constructional Steel Research, 70 (2012) 167-176.
[2] T. Okazaki, M.D. Engelhardt, Cyclic loading behavior of EBF links constructed of AStM A992 steel, Journal of constructional steel Research, 63(6) (2007) 751-765.
[3] P.W. Richards, Cyclic stability and capacity design of steel eccentrically braced frames, University of California, San Diego, 2004.
[4] P. Gálvez, Investigation of factors affecting web fractures in shear links, University of Texas at Austin, 2004.
[5] B. Chegeni, A. Mohebkhah, Rotation capacity improvement of long link beams in eccentrically braced frames, Scientia Iranica. Transaction A, Civil Engineering, 21(3) (2014) 516.
[6] N.D. Lagaros, L.D. Psarras, M. Papadrakakis, G. Panagiotou, Optimum design of steel structures with web openings, Engineering Structures, 30(9) (2008) 2528- 2537.
[7] M. Ohsaki, T. Nakajima, Optimization of link member of eccentrically braced frames for maximum energy dissipation, Journal of Constructional Steel Research, 75 (2012) 38-44.
[8] G. Arce, Impact of higher strength steels on local buckling and overstrength of links in eccentrically braced frames, University of Texas at Austin, 2002.
[9] K. Kasai, E.P. Popov, Cyclic web buckling control for shear link beams, Journal of Structural Engineering, 112(3) (1986) 505-523.
[10] ABAQUS, Dassault Systémes Simulia Corp., in, 2014.
[11] H. Amiri, A. Aghakouchak, S. Shahbeyk, M. Engelhardt, Finite element simulation of ultra low cycle fatigue cracking in steel structures, Journal of Constructional Steel Research, 89 (2013) 175-184.
[12] J.R. Rice, D.M. Tracey, On the ductile enlargement of voids in triaxial stress fields*, Journal of the Mechanics and Physics of Solids, 17(3) (1969) 201-217.
[13] A.M. Kanvinde, Micromechanical simulation of earthquake-induced fracture in steel structures, 2004.
[14] E. Kaufmann, B. Metrovich, A. Pense, Characterization of cyclic inelastic strain behavior on properties of A572 Gr. 50 and A913 Gr. 50 rolled sections, (2001).
[15] R. Eberhart, J. Kennedy, A new optimizer using particle swarm theory, in: Micro Machine and Human Science, 1995. MHS’95., Proceedings of the Sixth International Symposium on, IEEE, 1995, pp. 39-43.