Sharif Digital Repository

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... 

Systems composed of electrical and mechanical elements in micrometer scale are called microelectromechanical systems which are commonly fabricated on silicon substrates. These systems are in connection with environment by the means of sensors and actuators. Thermal microactuators as one of the most applicable actuators produce force and displacement on the basis of thermal expansion.Recently, by the advent of some polymers compatible with microfabrication methods such as SU8 and due to their remarkable thermal properties,polymeric thermal microactuators are attracting more attention in a way that polymeric type of almost every predesigned thermal microactuators are fabricated and much... 

Offshore jacket platforms are one of the most motivating structures for damage detection due to their importance and productivity. In this study, the goal is to investigate the application of finite element model updating as a robust method for damage detection in this kind of structure. This method is based on minimizing a cost function which shows the difference between some features of the model and damaged real structure. Therefore, this method can be used for damage detection by comparison between updated model, which is updated by measured data from damaged structure, and the initial model which precisely shows the previous or undamaged status of the structure. The vibration features... 

The study of bolted moment end-plate connections, both beam to column and beam to beam connections, is quite general and standard nowadays. Buildings which utilize such connections are widely being used and the reorganization of their significant benefits is growing. The research work reported in this thesis presents the results of several parametric analyses to determine the moment–rotation curve of bolted moment end-plate connections utilizing Rectangular Hollow Sections (RHS) and two rows of bolts using Finite Element Modeling (FEM). Previous experimental studies have focused on the moment-rotation relationship under pure bending. This project particularly involves further numerical... 

In the last decade Fiber Reinforced Polymer (FRP) widely has been used to strengthening the reinforced concrete (RC) members. Most of the research works have been concentrated on the design of shear members with FRP layers. Based on the reported results, increasing the shear reinforcement more than a certain amount, the shear capacity and ultimate strength of reinforced concrete deep beam does not increased, On the other hand, The presence of web openings in such beams is frequently required to provide accessibility such as doors and windows or to accommodate essential services such as ventilating and air conditioning ducts, So the external strengthening of the reinforced concrete deep beams... 

Endurance Time (ET) is a fairly comprehensive analytical method based on time history analysis applied for evaluating structural systems excited by dynamic loading of earthquake. In such evaluation assessment measure is based on endurance time of structure versus applied accelerogram function and parameters such as stiffness, lateral resistance, period of vibration and dynamic characteristics are not used directly. In this research nonlinear dynamic analysis of elevated steel tanks with laterally braced framed tower under the loading of earthquake records and ET accelerograms was studied and effectivity of ET method in analyzing such elevated tanks was verified. Due to complication of... 

The interaction of perpendicularly tunneling beneath existing metro station is investigated. In this paper E4R7 station, in line 7 of Tehran Metro (Tehran Urban and Suburban Railway co., TUSRC); Iran has been studied. This existing station has some special specifications such as a new pre-supporting system that is called Concrete Arch Pre-supporting System (CAPS). Construction of CAPS is mainly based on an Old Iranian small water tunnels excavation method, Quanat, which is faster and more economical than other common methods. CAPS is a rib like structure consisting of concrete piles and arch beams constructed around underground space before its construction. This method has been utilized in... 

With the emergence of a variety of surgical glues in the market and utilizing them in recent years, nowadays, based on the post-surgery studies, it has become transparent that there are additional factors, such as the long-term effect of surgical glues on tissue, to consider beyond the sealants ability to act as a mechanical barrier or a means to buttress friable tissue so that it can hold sutures. Mechanical properties of the surgical glues have especially a significant role in the applications that the tissue undergoes cyclic loading (such as arteries’ tissues). A mismatch between the mechanical properties of the tissue and the sealant can result in the remodeling of the artery that may... 

Financial losses and casualties due to the collapse of the masonry facade and the infill walls of the building in recent earthquakes were motivators of this research to study seismic performance assessment of masonry facade. One of the main reasons for the collapse of buildings facade is their inadequate connection to the infill walls and structure frame. The mentioned item caused when earthquakes such as Kermanshah earthquake occurred, although a large number of buildings remained undamaged in terms of their structural, facades of these buildings collapsed. The details of the masonry facade, such as the metal wires mentioned in the codes, are not usually applied in Iran, and the connection... 

Congenital heart defects are a type of heart diseases that some babies get at birth. These diseases generally have symptoms such as shortness of breath, headache, impaired blood supply, hyperplasia of the lungs, enlarged heart, and so on. In the past, open heart surgery was commonly used to treat such diseases, which was a costly and risky procedure. But over time, occluders made it easier. An occluder is referd to a device that is generally minimally invasive in the area of the fault and could block it. The occluders are usually braided type, with inside polyethylene fibers, where tissues can grow and clogs the defect over time. Although occluders have greatly increased the success rate of... 

Preservation of historical monuments is a very important issue for future generations. The importance of this issue is doubled when we know that most of these buildings are traditionally built and do not have a single structure to withstand seismic loads. One of such buildings in our country is Bam Citadel, which was completely destroyed as the oldest brick building in the world during the 2003 Bam earthquake.In this project, we will try to find a model that can determine the structural behavior of the historical dome of Soltanieh for engineers in a case study. This building is a brick dome with a height of 48.5 meters and a diameter of 24.4 meters from the seventh century , which is unique... 

Passive finite element (FE) models of the spine are commonly used to simulate intact and various pre- and postoperative pathological conditions. Being devoid of muscles, these traditional passive FE models are driven by simplistic loading scenarios, e.g., a constant moment and compressive follower load (FL) that do not properly mimic the complex in vivo loading condition of the spine under muscle exertions. The present works therefore aims to develop novel passive FE models that are driven by more realistic yet simple loading scenarios, i.e., in vivo measured vertebral rotations and pathological-condition dependent FLs (estimated based on detailed musculoskeletal finite element (MS-FE) spine... 

Tests have shown that concrete post-tensioned slab under heat condition suffer a significant reduction in stiffness and strength. Design and implementation of post-tensioned concrete slabs with large spans of industrial structures exposed to extreme variation in temperature can be possible with detailed research on its behavior under heating condition. In this study numerical modelling of PT concrete slabs with unbonded tendons under heating condition was created based on available test results in the literature. A parametric study has been carried out and the results are presented for concrete coefficient thermal expansion, thermal contact conductance between the concrete and the cables,... 

Gearbox is one of the important components of power transmission chain in the car which the engagement of the gears inside it causes noise. The following thesis, is in line with the project that was defined as "NVH reduction of the Tiba X200 gearbox" and to increase the correlation between university and industry, the aim of which was to improve all the noise sources in the mentioned vehicle. The purpose of this project is to reduce the noise of the gearbox shell by using reinforcing blades called ribs. For this purpose, first the desired changes were made in Solidworks software on the 3D model of the gearbox shell, and then the finite element model of the gearbox shell was prepared in... 

Millions of people due to factors such as osteoporosis, aging, sports incidents, and accidents face complications from bone fracture injuries every year. Nitinol shape memory alloy and Gyroid metamaterial have attracted researchers to use them as suitable replacements to fill empty areas of broken bones. In this research, numerical modeling and additive manufacturing were used to take advantage of the special properties of both nitinol and gyroid structures. In the modeling section, finite element modeling of the superelastic effect and the one-way shape memory effect of sheet and solid gyroids in cubic and cylindrical geometries with different porosities were done. As a result of the...