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High-mode effects on seismic performance of multi-story self-centering braced steel frames Can-Xing Qiu, Songye Zhu ⁎ a The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China b Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong Seismic-resisting, multi-story steel frames with self-centering braces (SCBs) are numerically investigated through pushover and ncremental dynamic analyses. The seismic performance of self-centering braced frames (SC-BFs) is systematically compared with that of buckling-restrained braced frames (BRBFs), with emphasis on high-mode effect. The concentration of inter-story drift in the upper part of the buildings is more significant in SC-BFs than in BRBFs as a result of this effect. This high-mode effect strengthens with the increasing intensity of ground motions. Parametric studies indicate that increasing the post-yield stiffness ratio and/or energy dissipation capacity can successfully improve the seismic performance of SC-BFs, particularly in terms of limiting the high-mode effect. SC-BFs with enhanced post-yield stiffness and energy dissipation capacity exhibit relatively uniform inter-story drift ratios and reduced record-to-record variability in seismic performance. © 2015 Elsevier Ltd. All rights reserved. Keywords: Multi-story steel frame Self-centering brace (SCB) High-mode effect Post-yield stiffness ratio Energy dissipation capacity 10.1016_j.jcsr.2015.12.008-High-mode-effects-on-seismic-performance-of-multi-story-self-centering-braced-steel-frames.pdf

Hysteretic Analysis of Steel Plate Shear Walls (SPSWs) and A Modified Strip Model for SPSWs Lanhui Guo1,*, Ran Li1,2, Sumei Zhang1 and Guirong Yan3 1School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China 2China Academy of Building Research, Beijing 100013, China 3School of Engineering, University of Western Sydney, Penrith, NSW 1797, Australia (Received: 7 April 2010; Received revised form: 14 February 2012; Accepted: 16 February 2012) Abstract: Steel plate shear walls (SPSWs) have become more and more popular in recent years because of their potential huge energy dissipation capacity and ductility under lateral loads. Due to their low cost and fast construction, SPSWs have potential application in practice. The finite element software ANSYS applied to the analysis of the hysteretic behavior of SPSWs is described in this paper first. It was found that compressive stress existed in SPSWs and the effects became more evident with decreasing height-to-thickness ratio. This was validated by comparing theoretical and experimental test results. Secondly, based on the analytical results, a modified strip model is proposed. In the modified model, the compressive effects in the panel were taken into account and it was then found that the load-carrying capacity and the energy dissipation capacity agreed well with the already carefully validated experimental results. Key words: finite element (FE), steel plate shear wall (SPSW), hysteretic behavior, strip model, energy dissipation capacity. 1369-4332.15.10.1751.pdf

Experimental and numerical study of unstiffened steel plate shear wall structures Meng Wang a,⁎, Yongjiu Shi b, Jian Xu c,Weiguo Yang a, Yixin Li b a School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China b Department of Civil Engineering, Tsinghua University, Beijing 100084, China c China Southwest Architectural Design and Research Institute Corp. LTD, Chengdu 610081, China a r t i c l e i n f o a b s t r a c t Article history: Received 13 March 2015 Accepted 6 May 2015 Available online 20 June 2015 Keywords: Unstiffened thin steel plate shear wall structure Hysteretic behavior Energy dissipation capacity Ductility Finite element method (FEM) Column stiffness In order to investigate the seismic behaviors of unstiffened thin steel plate shear wall structure, tests of four three-story unstiffened steel plate shear wall specimens under cyclic loads were carried out. Parameters of the specimens included height-to-thickness ratio, span-to-height ratio and middle brace. The carrying capacity, hysteretic behavior, degraded characteristics, ductility, failuremodes, energy dissipation capacity were analyzed and compared deeply. Besides, the nonlinear finite element method of shear wall structure was also established, which was verified by test results. Finally, the effect of column stiffness on load-carrying capacity was studied. The practical requirements of in-plane and out-of-plane stiffness of edge column were suggested. The experimental and numerical results showed that: this kind structure exhibits high strength, good energy dissipation capacity, and good ductility (the ductility coefficients are more than 3.0). When the inter-story drift angle reaches 1/50, the strength degradation is no more than 5%, indicating that the structure has good seismic behaviors. The span-to-height ratio has little effect on load-carrying capacity, while slightly affects the initial stiffness and ductility. The effect of height-to-thickness ratio (thickness) on load-carrying capacity is relatively larger than other factors. The middle braces do not improve the behaviors of structures. The stiffness of edge column has great effect on lateral load-carrying capacity of shearwall structures. The value of column stiffness index could bewithin 2.0–2.5 to achieve the sufficient constraints and economical benefit. 1-s2.0-S0143974X15001406-main.pdf