Construction of welded moment resisting connection is common. These connections have high potential for brittle failure of welds if quality of welding is not controlled. In this research new bolted bracket connection similar to Kaiser bolted bracket connection is introduced. Kaiser connection has invention patent so construction society can’t utilize them without authority. Proposed connection of this paper can be manufactured by both casting and welding methods and can eliminate patent problems. In this evaluation connection performance, pretention force of bolts, height of bracket, number of bolts and length of bracket have been evaluated. In modeling of connection in order to accuracy of results between different connected area and bolts faces contact elements were created. The standard cyclic history was selected for loading of specimens. The results shows that proposed connection can be accepted by connection code for using in special moment resisting frames from both ductility and strength aspects. Findings are extended as hysteresis curves, released energy of connection, rupture index indicators and slip of bolts.

Nowadays, building structures encounter with challenges such as construction speed and cost, especially in high seismicity zones. To accomplish this, steel structures was developed to accelerate the construction process and other economic issues. According to high strength ductility and energy dissipation, steel structure systems have been used widely in active seismic regions. The idea of application of shear panels has been using from many years ago as systems with high energy dissipation capability in EBFs as link beams and steel shear walls. The purpose of the EBFs design is the yielding of link beam and remaining the adjacent member at elastic region. According to the available criteria in design codes, shear in beams is a force-controlled action that exceeding the specified value as nominal strength is not permissible and the capacity design theory should be considered. Increasing the web thickness is the main effective factor achieving the needed shear strength and leads to the enhancement of plastic flexural capacity. The result of this action is more seismic demands in other structural members to keep in desirable operational level. So the shear plastic hinges is introduced instead of flexural plastic hinges at both ends. At this case because of uniform shear yielding through the web, energy dissipation capability is much better than the flexural yielding which begins from the outer face of the beam located on flanges. The web panels of built-up sections restrained by top and bottom flanges and two-sided transverse stiffeners have the ability to carry further loading beyond the web buckling load. The small lateral web displacements produced by excessive loading are not substantial because of available components to supply more resistance. Using adequate stiff transverse to resist against the out-of-plane deformation resulted from post-buckling,tension field actions are developed in shear panels before reaching the maximum shear strength by forming a truss with tension diagonals and compression verticals fixed by stiffeners. The concept of shear resisting frames with non-prismatic beams were presented with the scope of reduction in link beam rotation, elimination of architectural limitations, restrictions on the ratio of span free length to beam total depth and high energy dissipation capacity. Shear yielding and out of plane deformations caused by tension action field mainly control the frame behavior and energy dissipation. The proposed system is made up two strong side columns connected to the link element with weaker section in the middle of the frame as shear fuse with non-prismatic beams. Tendency to use haunched beams makes it feasible to achieve any link length ratio especially less than 1. 0. This paper presents the introducing, design and performance of 1-storyshear resisting frames with different link length ratios (ranges from 0. 5 to 1. 6 with 0. 1 variations) and shearcontrolled behavior. The goal is achieved by implementing pushover and cyclic analyses numerically with ABAQUS software. But at first a verification analysis is done to validate the modeling procedure and reach a good conformity between numerical and experimental results. The outputs are presented in the form of response modification factor, displacement ductility and overstrength factor for pushover analyses and hysteresis behavior, backbone curve, energy dissipation capability and overstrength factor for cyclic analysis. Also at the end, 3, 5 and 7-story-frames were studied through pushover analysis and values of response modification factor and overstrength factor of the total frames presented. The results indicate desirable behavior of 1-story-shear resisting frames from the point of stiffness and strength degradation with high values of response modification factor equal to 9. 18.

Applying elastic methods in the design of steel moment resisting frames (SMRF) and not recognizing the redistribution of moments in the inelastic range, do not guarantee a suitable seismic behavior in earthquakes. In order to be able to predict and control the inelastic behavior under seismic loading and to determine the corresponding load factor, the design of SMRF is studied in this paper. Classic concepts of plastic analysis and genetic algorithms are combined to arrive at an optimal proportioning of the frame members. Various examples, along with studies on the parameters of the employed genetic algorithm are also presented within this work.

In this paper, the influence of increasing the height of building on the seismic behavior of dual structural systems in the form of steel moment resisting frames accompanied with reinforced concrete shear walls has been investigated. Common structures experience inelastic stage of behavior encountering the seismic loads and the applied energy will be dissipated. The nonlinear responses of the structural models have been evaluated in this research. As a result, some parameters such as ductility factor of structure (μ), over-strength factor (Rs) and response modification factor (R) for the mentioned structures have been studied. To achieve these objectives, the buildings have 10 and 20 stories and contain such structural systems used to perform the pushover analyses having different load patterns. Regarding the results, it seems that the response modification factor (R) for the mentioned structural system is assumed to be higher than the value which is used in Iranian Code of Practice for Seismic Resistant Design of Buildings [Standard No.2800]. Analytical results showed that the ductility factor and the response modification factor increased as the structure height increased. In contrast, the over-strength factors increased by decreasing the height of the structure.