The knee bracing steel frame (KBF) is a new kind of energy dissipating frame, which combines excellent ductility and lateral stiffness. As the structural fuse of the frame, the knee element will yield first during a s...The knee bracing steel frame (KBF) is a new kind of energy dissipating frame, which combines excellent ductility and lateral stiffness. As the structural fuse of the frame, the knee element will yield first during a severe earthquake so that no damage occurs to the major structural members and the rehabilitation is easy and economical. To help fully understand the relations be- tween its seismic performance and the structural parameters, systematic elastoplastic analysis of the KBF structure with finite element method was conducted in this work. Finally, general design recommendations were made according to the results of the analysis.展开更多
In present paper application of Endurance Time Analysis （ETA） method in nonlinear seismic assessment of steel concentrically braced frames is studied. In this method structure is subjected to a set of predesigned in...In present paper application of Endurance Time Analysis （ETA） method in nonlinear seismic assessment of steel concentrically braced frames is studied. In this method structure is subjected to a set of predesigned increasing acceleration functions and various responses of the structure are recorded during synthetic seismic excitation. The averages of maximum values for various responses in Nonlinear Time-History Analyses （NTHA） extracted from real ground motions are expected to be close to those obtained from ETA up to equivalent target time. For this purpose a set of 9, 11, 13 and 15 stories steel frames were designed and plastic hinge method was selected as source of nonlinearity in all cases. Responses were compared based on interstory drift ratio and story shear in two methods and results show satisfactory consistency between two methods. Finally, it was concluded that the ETA method can be used as alternative method in nonlinear seismic analysis of concentrically braced steel frames.展开更多
Hoffa fracture is an uncommon injury. In the literature, lateral condylar Hoffa fracture is mentioned as a more common injury pattern than medial condylar Hoffa fracture. The mechanism of injury and method of treatmen...Hoffa fracture is an uncommon injury. In the literature, lateral condylar Hoffa fracture is mentioned as a more common injury pattern than medial condylar Hoffa fracture. The mechanism of injury and method of treatment is not very well described in the literature. We are present- ing a rare case of comrninuted medial condylar Hoffa frac- ture with ipsilateral patellar fracture. The mechanism of in-jury has not been described in the literature. Lag screw fixation, which is the most acceptable method of treatment, is not possible due to comminution. We explain the pos- sible mechanism of injury and fix the fracture with L-but- tress plate.展开更多
基金Project (No. 2002CB412790) supported by the National BasicResearch Program (973) of China
文摘The knee bracing steel frame (KBF) is a new kind of energy dissipating frame, which combines excellent ductility and lateral stiffness. As the structural fuse of the frame, the knee element will yield first during a severe earthquake so that no damage occurs to the major structural members and the rehabilitation is easy and economical. To help fully understand the relations be- tween its seismic performance and the structural parameters, systematic elastoplastic analysis of the KBF structure with finite element method was conducted in this work. Finally, general design recommendations were made according to the results of the analysis.
文摘In present paper application of Endurance Time Analysis （ETA） method in nonlinear seismic assessment of steel concentrically braced frames is studied. In this method structure is subjected to a set of predesigned increasing acceleration functions and various responses of the structure are recorded during synthetic seismic excitation. The averages of maximum values for various responses in Nonlinear Time-History Analyses （NTHA） extracted from real ground motions are expected to be close to those obtained from ETA up to equivalent target time. For this purpose a set of 9, 11, 13 and 15 stories steel frames were designed and plastic hinge method was selected as source of nonlinearity in all cases. Responses were compared based on interstory drift ratio and story shear in two methods and results show satisfactory consistency between two methods. Finally, it was concluded that the ETA method can be used as alternative method in nonlinear seismic analysis of concentrically braced steel frames.
文摘Hoffa fracture is an uncommon injury. In the literature, lateral condylar Hoffa fracture is mentioned as a more common injury pattern than medial condylar Hoffa fracture. The mechanism of injury and method of treatment is not very well described in the literature. We are present- ing a rare case of comrninuted medial condylar Hoffa frac- ture with ipsilateral patellar fracture. The mechanism of in-jury has not been described in the literature. Lag screw fixation, which is the most acceptable method of treatment, is not possible due to comminution. We explain the pos- sible mechanism of injury and fix the fracture with L-but- tress plate.
