Braced frame vs perfect balance5/7/2023 “An energy based method for seismic evaluation of structures”. ), ( Leelataviwat S et al., 2007 Leelataviwat S. “Toward Performance-Based Seismic Design of Structures”. To solve this problem, the performance-based plastic design (PBPD) method has been introduced [( Leelataviwat S et al., 1999 Leelataviwat S. In this method, which is not in compliance with the real behavior of the structure, undesired and unpredictable damages may be imposed to the structure. This method is called the Capacity Design Method. ![]() Design of other members is performed based on the maximum force produced by the fuse elements. Fuse elements must also have enough ductility to dissipate seismic energy. ![]() Fuse elements are designed based on the seismic loads. Usually nonlinear behavior of structures appears on specific parts of structural members such as end of beams and columns in moment frames and diagonal members in concentrically braced frames. The nonlinear behavior of structures under severe earthquakes is conducted to the calculation of base shear indirectly by many parameters such as Response modification factor (R) Over-strength coefficient (Ω) and displacement amplification factor (Cd). The distribution of base shear over the high is also based on elastic behavior of the structure. The base shear is then distributed over the high of the structure. Most structural design codes use elastic behavior of structures to calculate seismic base shear based on many parameters such as structural system, geometry and site location. PBPD (Performance-based Plastic Design) Dual systems Plastic hinge Story drift Plastic rotation of the links The results also show that the collapse probability of frames that are designed by PBPD method is acceptable. However the yield mechanism is controllable and plastic deformation capacity of structures are better conducted to design in PBPD method. Results show that dual frames that are designed by PBPD method have less stiffness and strength than frames that are designed by ordinary method. To assess the behavior of each system, nonlinear pushover and time history analysis are conducted. In this regard, three 6, 12 and 20 story structures are designed based on PBPD and conventional method. In the proposed PBPD method, the shear resistance of each system is selected at the beginning of design process and this criterion can be contributed to the design process directly. ![]() As a code requirement, in dual systems the moment frame must be able to resist at least 25 percent of the base shear. In this study, the PBPD method is extended to the dual system of moment and eccentrically braced frames. To solve this problem, in recent years the Performance-based Plastic Design (PBPD) method which considers the plastic behavior of the structure, has been proposed. This may lead to unsuitable design and may cause undesirable damages to the structure. Most structural design codes use elastic analysis to calculate and distribute seismic base shear over the height.
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