1. INTRODUCTION In earthquake engineering, reducing the earthquake damage on buildings has been one of the most important issues in recent years. Passive energy dissipation systems are considered as one of the basic technologies used to protect buildings from earthquake effects and minimize seismic damage. These systems include a range of materials and devices for enhancing damping, stiffness and strength which mitigate the seismic hazards (Soong and Dargush 1997; Constantinou et al. 1998; Soong and Spencer 2002). Seismic dampers are one of the passive systems which are installed in the buildings to absorb the energy of the Advances in Structural Engineering Vol. 14 No. 6 2011 1247 Modifying the Shear Buckling Loads of Metal Shear Walls for Improving Their Energy Absorption Capacity S. Shahab 1 , M. Mirtaheri 2 , R. Mirzaeifa 1 and H. Bahai 3,* 1 George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA 2 Department of civil Engineering KNT University, Tehran, Iran 3 School of Engineering and Design, Brunel University, Uxbridge, UB8 3PH, UK (Received: 23 June 2010; Received revised form: 7 March 2011; Accepted: 14 March 2011) Abstract: In this paper, an approximate method is proposed for achieving predefined increases in the buckling threshold of a metal shear wall in order to increase its energy absorption capacity. The first and second-order derivatives of shear buckling loads of a shear wall with respect to the thickness in its different regions are calculated. Based on these eigenderivatives, and by using the first and second order Taylor expansions, the necessary change in the thickness of plate in various regions is calculated for increasing the shear buckling loads by a specific value. The presented modification algorithm is implemented for shear walls with different aspect ratios, material properties and boundary conditions. An initial sensitivity analysis is carried out for finding the regions within the shear wall where modifying the thickness has the most influence on the buckling loads. Based on the sensitivity analysis results, appropriate regions of plate are selected and the necessary modification in thickness of these regions is calculated for achieving a relatively large predefined change in shear buckling load. By simulating the post-buckling response of both initial and modified plates in a case study, the improvement in the energy absorption capability of the modified plate is also studied. Key words: shear wall, shear buckling, eigenvalue, eigenvector, sensitivity analysis. ground motion in the buildings. When seismic energy is transmitted through the dampers, a portion of energy is dissipated and the motion of building is damped (Soong and Spencer 2002). Among various types of seismic dampers, the metallic yield dampers are efficient means to dissipate the earthquake energy through inelastic deformation of metals. The metallic yield dampers can be found in different geometric configurations of X- shaped, E-shaped, honeycomb-shaped and shear walls. In earthquake engineering, thin steel shear walls have had an important role because of their unique performance characteristics. Shear walls can easily provide high in-plane strain and stiffness. In addition, * Corresponding author. Email address: hamid.bahai@brunel.ac.uk; Fax: +44-1895-256392; Tel: +44-1895-265773.