Finite Element Analysis of Squat Concerte Shear Walls with Rectangular Section under Static Monotonic Loading

Authors
F. Mohammadi Darani 1
A. Sarvghad Moghadam 2
1 Islamic Azad University
2 International Institute of Earthquake Engineering
Abstract
Squat shear walls are common in low-rise buildings, their seismic rehabilitation, lower stories of high-rise buildings, and nuclear power plants. Wall segments formed by openings also have the same behavior as squat shear walls. Usually walls with aspect ratio less than 1.5 are known as low-rise or squat shear walls. Shear stresses have significant effect in lateral strength and ductility of such walls. Concrete structures with shear dominant behavior are more complex for Analyzing and their seismic behavior may be poor. Also squat shear walls have various failure modes under lateral loading. In recent years designers have intended to performance based assessment and design of structures. Thus, reliable instruments for nonlinear analysis of squat shear walls are required. Previous efforts to nonlinear modeling of squat shear walls usually were performed by FE codes such as ABAQUS, ADIANA and VecTor2. These codes are not practical for performance based assessment and design of structures. Performance based assessment software programs such as SAP 2000 and PERFORM 3D are more desired to modeling complex structures. Accordingly, there is a need for reliable modeling techniques for nonlinear modeling of squat shear walls using performance based assessment software programs. The purpose of this paper is to finding suitable information for fast and reliable modeling of squat concrete shear walls with widely used building structural software programs. Therefore, by selecting and modeling five test specimens from previous experimental studies using two widely use commercial codes, SAP 2000 and PERFORM 3D, Key parameters for modeling such walls are found and calibrated to bring analytical results near the test results. These software programs employ fiber (layered) model to modeling wall panels. In this model, the member is divided into several segments, and each segment consists of parallel layers. Some layers would represent the concrete material and other layers would represent the steel material. The constitutive laws for concrete and steel materials are defined and assigned to appropriate layer. Different approaches are employed for modeling shear behavior of concrete using this method. In addition to the concrete axial/flexural layer, a shear layer must be implemented; shear constitutive laws are needed for modeling this layer. Also shear behavior of concrete can be modeled using diagonal layers. In these layers shear stresses convert to axial stresses acting on the principal plane of the layer and axial constitutive laws will be used. Results show that, estimated strength and force-displacement curve are in the good agreement with experimental results. concrete diagonal layer characteristics and tension modeling method of concrete are key parameters for modeling squat shear walls using SAP 2000 and concrete shear layer characteristics are key parameter for modeling squat shear walls using PERFORM 3D. It can be said that strength is better estimated than stiffness using this type of analysis.

Keywords

[1]  Elwood, K.J.; Matamoros, A.; Wallace, J.W.; Lehman, D.; Heintz, J.; Mitchell, A.; Moore, M.; Valley, M.; Lowes, L.N.; Comartin, C.; Moehle, J.P.; Update to ASCE/SEI 41 Concrete Provisions, Pacific Earthquake Engineering Research Center (PEER Center), 2007.
[2]  Shear Wall ISP NUPEC’s Seismic Ultimate Dynamic Response Test, Comparison Report, OECD/NEA/CSNI, Issy- Les-Moulineaux, France, Report No. OCDE/GD (96)188, Committee on the Safety of Nuclear Installations OECD Nuclear Energy Agency, 412, 1991.
[3]  ABAQUS Standard, version 5.3, Hibbit, Karlsson & Sorensen, Inc.,Pawtucket, RI. 1991.
[4]  ADIANA, version 6.1.5, R&D, Inc., Watertown, MA. 1991.
[5]  Palermo, D.; and Vecchio, F.J.; Behavior and Analysis of Reinforced Concrete Walls Subjected to Reversed Cyclic Loading, Publication No. 2002-01, Toronto, Department of Civil Engineering, University of Toronto, 351, 2002.
[6]  Wong, P.S.; Vecchio, F.J.; VecTor2 and Formworks user’s manual, Toronto, Dep., Civil Engineering, Univ. of Toronto, 2002.
[7]  Gulec, C.K.; Whittaker, A.S.; Performance-Based Assessment and Design of Squat Reinforced Concrete Shear Walls, Technical Report, MCEER-09-0010, 2009.
[8]  CSI Analysis Reference Manual For SAP2000, Berkeley, California, Computers and Structures, Inc., April 2009.
PERFORM COMPONENTS AND ELEMENTS FOR PERFORM-3D AND PERFORM COLLAPSE. VERSION 4, Berkeley, California, Computers and Structures, Inc., 2006
[1]      Wirandianta, S.; Saatciuglu, M.; Tests of Squat Shear Wall Under Lateral Load Reversal, Proceedings, The 3rd US Conference on Earthquake Engineering, Charleston, South Carolina, 1986.
[2]      Kuang, J.S.; Ho, Y.B.; "Seismic Behavior and Ductility of Squat Reinforced Concrete Shear Walls with Nonseismic Detailing"; ACI Structural Journal; 105(2), 225, 2008.
[3]      Lefas, I.D.; Kotsovos, M.D.; Ambraseys, N.N.; "Behavior of Reinforced Concrete Structural Walls: Strength, Deformation Characteristics and Failure Mechanism"; ACI Structural Journal; 87(1), pp. 23-31, 1990.
[4]      Greifenhagen, C.; Seismic Behavior of Lightly Reinforced Concrete Squat Shear Walls, PhD thesis, Lausanne EPFL, 2006.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
[5]      Building Code Requirements for Structural Concrete (ACI 318) and Commentary, American Concrete Institute Committee 318, 2008.
[6]      Mander, J.B.; Priestly, M.J.N.; Park, R.; "Theoretical Stress-Strain Model for Confined Concrete"; Journal of Structural Engineering; 114(8), pp. 1804-1826, 1988.
[7]     خیرالدین, ع.؛ مرتضایی, ع.؛ تحلیل غیرخطی سازه های بتن آرمه به کمک روش اجزای محدود، دانشگاه سمنان، 176، 1386.
Modares Civil Engineering journal
Volume 13, Issue 4
November and December 2013
Pages 113-123