On the characteristics and seismic study of Hat Knee Bracing system, in steel structures

  • JafarRamaji, Issa (Department of Civil Engineering, Sharif University of Technology) ;
  • Mofid, Massood (Civil Engineering Department, Center of excellence in structures and earthquake engineering, Sharif University of Technology)
  • Received : 2010.09.12
  • Accepted : 2012.03.22
  • Published : 2012.07.25


In this study, a new structural bracing system named 'Hat Knee Bracing' (HKB) is presented. In this structural system, a special form of diagonal braces, which is connected to the knee elements instead of beam-column joints, is investigated. The diagonal elements provide lateral stiffness during moderate earthquakes. However the knee elements, which is a fuse-like component, is designed to have one plastic joint in the knee elements for dissipation of the energy caused by strong earthquake. First, a suitable shape for brace and knee elements is proposed through elastic studying of the system and several practical parameters are established. Afterward, by developing applicable and highly accurate models in Drain-2DX, the inelastic behavior of the system is carefully considered. In addition, with inelastic study of the new bracing system and comparison with the prevalent Knee Bracing Frame system (KBF model) in nonlinear static and dynamic analysis, the seismic behavior of the new bracing system is reasonably evaluated.


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