رفتار غيرخطي قابهاي با سيستم مهاربند زانويي تحت تاثير زلزله

Nonlinear Analysis of Knee-braced Frames under Earthquake Loadings

The new knee-braced frames (KBE) consiss of a moment resisting frame and diagonal braces connected to short knee elements. The lateral stiffness is provided by the frame and braces while flexural yielding of the knee elements provides the ductility. In this paper, the effects of geometric parameters on lateral elastic stiffness of KBF frames are studied and the suitable limits for these parameters are determined for the first time. Then, nonlinear dynamic seismic behavior of one kind of KBF frames (TKBF) and the effects of important parameters under Naghan and Elcentro earthquakes are studied and evaluated The seismic behavior of TKBF frames are compared with CBF and EBF frames. The results prove that suitably designed TKBF frames show better seismic behavior according to lateral nonlinear displacement, plastic hinge propagation, collapse mechanism, and vertical displacements of slabs, and, therefore, provide better stiffness and ductility requirements.