Buckling-Restrained Braced Frame system(BRBFs) are a new type of steel seismic-load-resisting system that has found use in several countries because of its efficiency and its promise of seismic performance far superior to that of conventional braced frames. The system is addressed in the 2005 edition of the AISC Seismic Provisions for Structural Steel Buildings, also a set of design provisions ...

BACKGROUND Despite several studies with different methods, the effect of functional knee braces on knee joint kinematics is not clear. Direct visualization of joint components through medical imaging modalities may provide the clinicians with more useful information. OBJECTIVES In this study, for the first time in the literature, video fluoroscopy was used to investigate the effect of knee br...

The seismic performance of elliptic braced moment resisting frame (ELBRF) is assessed here and is found that the structural behavior is improved and is of free of architectural space. The demand for seismic performance of ELBRF is estimated through conventional pushover methods of 3, 5, 7, and 10-story ELBRF frames and they are compared with special moment resisting frames (SMRF) and X-Braced C...

from the time that civil engineers have used steel in building structures, they tried to increase its strength so as to produce more economic and lighter structures by using more elegant sections. increase of steel strength is not always useful for all members of a steel structure. in some members under certain conditions, it is needed to reduce the strength as much as possible to improve the b...

the rotational friction dampers can be improved the seismic behavior of the steel structures, and they can be reduced the internal forces in the bracing members, columns and the other structural members. in this research, a simple method for modeling and analysis of braced frames equipped by these dampers is proposed. the proposed model describes seismic behavior of dampers very well and it is ...

braced frames structures have a good lateral stiffness against earthquakes. however, energy loss of their members is slight and strong forces are given to the structures. moment frames have a more flexible function against earthquakes and also have a better flexibility than braced frames. however, since its lateral stiffness is low, too much displacement of the structure results in an increase ...

This study is devoted to seismic collapse safety analysis of performance based optimally seismic designed steel chevron braced frame structures. An efficient meta-heuristic algorithm namely, center of mass optimization is utilized to achieve the seismic optimization process. The seismic collapse performance of the optimally designed steel chevron braced frames is assessed by performing incremen...

Objectives: To determine if immobilization of the knee at varying degrees of knee flexion will limit the surface electromygraphical (sEMG) activity of hamstring muscles during crutch-assisted ambulation. Methods: Ten healthy participants walked with crutches with the knee maintained at 0°, 30°, 60° and 90° of knee flexion, both with and without a brace. The leg was non-weight bearing for all tr...