In the event of an earthquake occurring in steel Frames structures, if the lateral load-resisting system is a moment frame structure, these beams will dissipation of energy and developed plastic hinge in the beam, but this requires a strong connection that must be made in the design of the structure. A zone of beam and column connection exposed to flexural and shear stresses. This zone is considered as a sensitive area of the bending frame; if this area does not do its job properly, the transmission of force between the beam and the column is not properly executed and the structure will be damaged seriously. The reputable regulations of the world have considered certain criteria for this area and they are called connection springs. In this study, four models were designed to examine the force mechanism of this section and the behavior of this part is investigated. Contrary to expectation, a huge share of the cut is transmitted in scarves and underpants. In the next step, a model is designed to give the source of the connection a surrender. In this case, the shearing sheet transmits a negative cut into scarves and cufflinks.

Rivers have a prominent role as one of the most important water resources that are constantly evolving. Therefore, recognition of the behavior and morphology of rivers, which is influenced by factors such as river form and structure, river geometry, bed shape, flow flow and characteristics of the river profile, is of particular importance in river engineering designs. These effects are very important in the meander rivers where there is an uneven flow in terms of velocity changes, shear stresses, water surface digits, and so on. In this research, an interval of the Karkheh River with an arch was selected. Then, the depth of water and the speeding were measured in three sections (input, arc and output) by field operations. In the following, using the two-dimensional model of CCHE2D flow, the daily flow of the river was modeled in non-sustained conditions in 2014. The results of this study indicate that the use of the CCHE2D model is efficient in simulating the flow pattern of the river.

The bending connections Beam to the Cruciform Column in Iran are increasing. Normal columns, such as columns I and H, have the ability to connect two Beams. Cruciform Columns the ability to connect 3,4 Beams. This requires a strong connection that should be considered in the design of steel structures. One of the members of the connecting Panel Zone. In the design Codes, the relationship between the yield point and final point of the panel zone in the H columns was presented.The purpose of this study is to investigate the behavior and strength of panel zone in cruciform columns. For this purpose, the modeling has been used by ABAQUS software. In the first step, numerical modeling has been confirmed with laboratory verification. In the second step, by designing and modeling 20 numerical models, the strength of the panel zone is investigated. According to the results of models, it was found that for the Cruciform Column it is not possible to use the relations provided for H columns. As a result, there are relationships for determining the strength of panel zone in cruciform columns in an elastic and non-elastic state, provided that the rotation of the coupling fence is not quadrupled above the elastic limit.

The effect of severe earthquake movement time is one of the most important and ambiguous parameters in the structures. This parameter along with the magnitude and distance from the fault are the determinant factors in the failure of the structures and the study of the factors affecting the performance of this index on the structure seems necessary. In this research, we tried to study the past research to conduct the right research, and to clarify the hidden aspects of work that can lead to the performance of the structures until complete failure.

In this paper, the reinforced concrete frames with concrete shear walls are studied from the perspective of the performance-based design method. The shear wall is modeled as an equivalent column with a rigid beam on its top and its hinges are assigned to the equivalent column depending on the moment or the shear governing the behavior of the wall. For this purpose, two-dimensional models of three reinforced concrete frames with concrete shear walls are created. Models with 5, 10 and 15 floors are created to represent the low-rise, mid-rise and high-rise buildings. The models are investigated using the traditional pushover analysis in SAP software. Moreover, adaptive analyses including force-based adaptive pushover (FAP) and displacement-based adaptive pushover (DAP) are conducted using SEISMO STRUCT software.

To investigate the validity, the results of the pushover analysis are compared with the results of nonlinear time history analysis. For nonlinear time history analysis, 7 far field earthquake records which were recorded from soils with shear wave velocities between 175 to 375 meters per second at a distance of approximately 20 km far from the epicenter of the earthquakes are selected.

Shear walls are one of the most lateral- forces resistant systems which have been nicknamed "shear walls" due to their high shear force absorption. Bending deformation of these structures is noticeable which results in great tensions at the foot of the wall. These walls are divided into two groups of reinforced concrete and steel walls and their behavior are different from each other. Reinforced concrete shear walls have high out- of- plane stiffness which prevents them from buckling but steel shear walls have low out- of- plane stiffness and their behavior is affected by diagonal traction fields which results in shear capacity reduction. In order to prevent these walls from buckling, steel plates are connected to concrete panels by means of shear studs. Coupling of steel shear walls changes their behavior and steel plates reach their ultimate capacity. Therefore, in this study, nonlinear static behavior and seismic parameters of composite shear walls system have been investigated. At the beginning of the research, a sample of the laboratory model has been verified to ensure the modeling of the composite shear wall in the nonlinear behavior range. In the next study, a double-skinned steel frame system and five-story compound shear walls were designed in a panel based on a reasonable behavior coefficient. In ABAQUS software, non-linear static modeling and analysis was performed and seismic parameters This system has been calculated for its behavior coefficient and shape. The results of the seismic parameters derived from this model are in good agreement with previous studies.

According to researches and experiments conducted by researchers, it is accepted that shear walls have significant structural parameters such as lateral stiffness, shear capacity and energy absorption. These walls are known for their shear force due to the shear force absorption, while flexural deformations occur, and stresses from the bending anchor at their feet are remarkable. Now, if we connect two adjacent and separate shear walls together with very difficult towed beams, the strength and behavioral properties of these walls will change greatly. So, to clarify this, at the beginning of the present study, the relationships between the elastic analysis of the system are reviewed in a continuous method. In the next study, a 10-story coupled shear wall system is compared with the results of ABAQUS software based on the continuous method of elastic analysis. According to studies, the lateral displacement in the system of the coupled shear walls is increased and the lateral stiffness decreases. Also, the bending anchor in the shear walls is sharply reduced relative to the uncoupled shear walls, but the shear force does not change in each of the walls, but very large shear force are formed in the coupled beams, which are Axial force is transmitted to the walls. In general, the presence of coupled beams in the system of uncoupled shear walls significantly reduces the stress at the foot of the walls and makes the lateral deformations in the walls to be flexed to the shear.

In today's world, with the rapid advancement of science and technology, new materials are emerging every day, in which alloys of memory are a form of these materials. Since the use of the frame system with conventional bracing is not responsive to structural requirements due to limitations such as low wear ability, buckling bracing in the pressure and reducing load capacity, so the use of this type of alloy in brackets can be a breakthrough. In this research, the effect of braces with intelligent memory alloys on energy dissipation and steel frame formation is investigated by modeling in ABAQUS finite element software. The braiding function is modeled in several modes: braiding consisting of steel, memory alloy, memory alloy and steel along the length and cross section of the bracket with different sizes in the form of 7 numerical models in Abaqus software and their results are compared. In two models, one of which has only memory-alloy materials and the other steel materials, the analysis of the results showed that the final weight of the braiding material is about 16% more than the bracelet with alloys of memory. Also, the initial hardness and maximum stress and energy consumption are higher than the steel model. In models that use a combination of two compositions of memory alloy and steel in a cross-sectional curtain (in different ratios), reducing the steel's percentage has a very small effect on reducing the final load and the energy consumption of the bracing. The results showed that the initial stiffness and energy consumption of the two models are approximately equal to those of the curtain that had 50% of the cross-sectional length and the bracelet length of the steel and the rest of the memory alloy. But the final load and the stress of a model in which two materials in the cross-sectional area are 18 KN and 115 Mpa, respectively.

As the aim of nonlinear seismic analysis is to recognize real behevior of structures against future earthquakes.Hence in order to the possibility of replacement of dynamic methods by simple and adaptive pushover analysis methods,in this research ,the Adaptive Pushover Analysis Method (APAM) with two option displacement force types (DAP&FAP) is considered for three types of concrete intermediate flexural frame buildings due to iranan seismic code 2800 (short 5stories,intermediate 10stories,high 15 stories).In this method,the results of upper modes effects on seismic behavior structures are evaluated and compared to Time History Analysis Method (THAM) results as a dynamic method.To established common and adaptive pushover analysis methods , SAP2000 and Seismostruct softwares are employed respectively.In the consequence base shear force,roof displacement and drift parameters:DAP method for 5 and 15 stories ,common pushover method for 10 stories have the closest results to THAM.