Sharif Digital Repository

Steel shear wall systems have been introduced as a lateral load resisting system since 1970s. Based on the designer’s choice, this system can be used with or without stiffeners. Employing stiffeners prevents the elastic buckling of steel plates which can enhance the system to absorb more energy. The design code for using stiffners has not developed yet in Iran since this kind of systems is not common practice. In this study, the Response Modification Factor (R), as an important factor in the design procedures of structures, is investigated for 2 to 10-story building structures which have steel shear walls with 3 and 6 millimeters thickness with 3, 4 and 6 meters spans.To this end, the... 

Concrete filled double-steel-plate (CFDSP) composite wall is a new lateral resisting system that recently used in design and strengthening of high-rise buildings. This CFDSP composite wall is composed of concrete filled steel tubular columns at the two boundaries and concrete filled double-steel-plate wall body. The main advantage of this system is the interaction between steel and concrete which delays local buckling of steel plates. Also, steel jacket increases the strength of concrete in result of confinement effects. Furthermore, these systems have lower thickness compared to ordinary concrete shear walls. Hence, they have less structural weight which reduces the earthquake force.... 

In this study, the behavior of diagonally stiffened steel plate shear wall systems which have a new configuration of stiffeners is investigated. This dissertation is divided into three main sections which contain experimental studies, finite element analysis and developing design equations. In the section on experimental studies, 5 single-bay, single-story, one-third scale specimens were tested. An unstiffened specimen as a control sample and two other specimens with different configuration of stiffeners were constructed and tested to study the effect of diagonal stiffeners. Based on the observations during the tests, it was decided to add and study two other specimens too, including one... 

In this study, high frequency vibration analysis of two connected plates by a beam interface is carried out using Energy Finite Element Analysis (EFEA). In structural vibration analysis at low frequencies, classical methods such as Finite Element Method or Boundary Element Method present accurate results. But, using these methods at high frequencies requires expense of high calculation cost and time. Therefore, using of statistical methods that are based on average estimates of vibrations, at high frequencies is most popular. EFEA is a method that gives average response of structure at a certain point and frequency band. This method is developed on the basis of finite element analysis of... 

As steel shear walls are usually applied in the central cores of buildings (around the elevators and stairs), the use of opening as door is inevitable in steel shear wall spans. On the other hand, because of weakening the performance of steel shear walls due to the presence of these openings, it is necessary to apply stiffeners around it. The use of stiffeners around all sides of opening continued to beams and columns, is very expensive. Therefore, the necessity of studying on the effect of different arrangements of stiffeners on the behavior of steel shear walls is felt. In this research, a number of steel shear walls with different characteristics in terms of plate aspect ratio, location... 

According to key importance of bridges in transportation system vital routes, a need to study and survey of bridges against destructive factors exist. Among these, bridges with concrete deck are widely used. One of the most important factors in destruction of these bridges is steel reinforcements corrosion and destruction of bridge deck. So in order to reduce the aggregation of reinforcements in critical sections and performance improvement of deck beams, a reinforcing substance which is not only resistant against corrosion but benefits from high resistance and stiffness is implemented.In this research the case studied bridge is simulated by finite elements software in two cases; reinforced... 

In this research, the dynamic behavior of a rotating stiffened cylindrical shell has been investigated using the refined finite element method. Refined FEM means decreasing degrees of freedom based on decoupling the structure to longitudinal and layerwise directions. The refined FEM has been used to solve the 3D rotor dynamics equations. The natural frequencies and the corresponding modes have been calculated and verified for some existed data and problems. In addition, the effects of the shell geometry dimensions on the natural frequencies and mode shapes have been studied. Also, the relationship between the length to radius ratio, radius to thickness ratio, rotational speed, Aspect ratio... 

This study aims for investigating a novel type of Steel Plate Shear Wall (SPSW) system in which the plate to boundary column connections are eliminated and the plate is reinforced with side, horizontal or cross stiffeners. SPSWs are one of the best lateral load resisting systems specially in high-rise buildings which makes it to be widely used in modern construction projects. SPSW system was first used in Japan and United States and found its way to other countries through the next years. In contrary to United States, stiffened SPSWs are more popular in Japan as it is a high seismic area. Despite the numerous advantages of this system, the main drawback of SPSWs is the large column sections... 

In recent years world countries faced with the ageing aircraft fleet problem which increased the repair and maintenance costs of these aircrafts. The non-destructive inspection methods are common inspection methods of old aircrafts. To do this, the aircraft must test with a certain time scheduled inspection programme in a hangar. This method not only increased the repair and maintenance costs but also affects the flight schedule. To overcome this problem, the structural health monitoring can use to online monitoring the structure and when it needs for repair, the aircraft send to hanger. So, repair and maintenance costs minimize while the flight schedule less affected. One of the structural...