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shear
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Bending Analysis of Rectangular FG Micro Plates using Modified Couple Stress Theory and first Order Shear Deformation Theory
, M.Sc. Thesis Sharif University of Technology ; Fallah Rajabzadeh, Famida (Supervisor) ; Farrahi, Gholamhossein (Supervisor)
Abstract
Based on the modified couple stress and Mindlin plate theories, a Levy type solution is presented for bending and vibration analysis of rectangular isotropic micro plates with simple supports at opposite edges and different boundary conditions at the other two ones. Modified couple stress theory is taken into account to capture the size effect and the governing equations are derived using Hamilton's principle, and solved by Levy solution and space-state method. The results are verified with the existing ones in the literature. As a benchmark, additional tables for vertical deflections and free vibrations of plate with various boundary conditions are presented
Stress Analysis of in Cross-ply Laminates in Bending
, M.Sc. Thesis Sharif University of Technology ; Nosier, Asghar (Supervisor)
Abstract
In the present study, an analytical solution is developed to calculate the interlaminar stresses in long generally cross-ply laminated composite plates subjected to bending. At first, upon the integration of the strain-displacement relations and using the existing patterns in deformation of the long laminate, the general displacement field is extracted and simplified to the final form. Presented solution is based on a combined method containing the equivalent single-layer (ESL) theories beside the Reddy’s layerwise theory. In this method, the equivalent single-layer theories are utilized because of their simplicity and low computational efforts rather than the layerwise theory in evaluation...
Design and Fabrication of a Microfluidic Kidney Nephron-on-Chip Platform
, M.Sc. Thesis Sharif University of Technology ; Saeedi, Mohammad Saeed (Supervisor) ; Hajilouy Benisi, Ali (Supervisor) ; Moghadas, Hajar (Co-Supervisor)
Abstract
In this manuscript, we designed and fabricated a novel integrated microfluidic Kidney Nephron-On-Chip. This chip is able to culture cell monolayers under various fluid shear stresses and divert osmotic pressure gradients while imposing four different concentrations of an injected drug on cells. The multi-layer platform consisting of two bubble-trappers to eliminate all unwanted bubbles from the system, a concentration gradient generator to generate four different concentrations of the injected drug, and a membrane-based cell culture chamber caple of providing renal cells with their in-vivo condition. Using colorimetric techniques, the bubble trapper ability was quantified at flow rates up to...
Experimental and Numerical Studies on Trapezoid Ally Corrugated Steel Shear Walls with Opening under Cyclic Loading
, Ph.D. Dissertation Sharif University of Technology ; Mofid, Masood (Supervisor)
Abstract
Steel shear wall is a lateral load resistance system, which has been taken into consideration in recent decades for designing and reinforcing high-rise buildings. This system is comprised of steel filler panel surrounded by frame members including beams and columns. Steel shear walls are presently fabricated in two types, stiffened and unstiffened. According to numerous conducted research, it can be stated that the stiffened type has better seismic performance. The use of stiffeners with a great number of executive details is required to spend more time and costs on the construction sector. In order to solve these problems, some experimental and numerical studies have been conducted on...
Effect of Different Defects of Spot Welded Joint in Automotive Body on Fatigue Strength: Experimental and Numerical Investigation
, M.Sc. Thesis Sharif University of Technology ; Farrahi, Gholamhossein (Supervisor) ; Mehmanparast, Ali (Supervisor) ; Reza Kashyzadeh, Kazem (Co-Supervisor)
Abstract
On average there are to resistance spot welding connections per vehicle. The quality of these welding directly affects the quality of the finished product and the strength of the vehicle against various loads, including road roughness, different maneuvers and even sudden impacts from accidents. During the spot welding process, unintentional failures occur due to the wrong choice of current, force and time. The aim of this study is to investigate the fatigue strength of three-sheets welding joints in numerical and laboratory methods, considering the defects of (Undersize weld, Stick, edge of sheet metal and Edge of sheet metal-SECANT) . For this purpose, a healthy spot welding model was first...
Dynamic Parameters of Saturated and Unsaturated Sand at Different Range of Shear Strain Levels in Cyclic Simple Shear Test
, M.Sc. Thesis Sharif University of Technology ; Jafarzadeh, Fardin (Supervisor)
Abstract
In this investigation, a series of cyclic simple shear tests were carried out in order to evaluate dynamic parameters of Babolsar and Toyoura sand at levels of saturation 25, 50, 75 and 100%. 96 tests were conducted using SGI type cyclic simple shear device. The specimens were cylindrical, with 7cm diameter and 2.2 cm height. The tests were performed under both drained condition (constant-load) at levels of saturation 25, 50%, and undrained condition at levels of saturation 75, 100%. All tests were performed under vertical consolidation stress of 50 and 150 kPa, relative density of 30 and 70% and cyclic shear strain of 0.5, 5 and 10%. The tests were shear strain-controlled with an...
Free Vibration Analysis of FG Annular Sector Plates Using Extended Kantrovich Method
, M.Sc. Thesis Sharif University of Technology ; Fallah Rajabzadeh, Famida (Supervisor)
Abstract
In this study the free vibration of annular sector plates made of functional materials with using the extended Katrovich method is investigated for a variety of boundary conditions. For this purpose, based on the first order shear deformation theory and Hamilton's principle, equations of motion that they are five differential equations and coupled, are derived. Due to the difficulty of the equations obtained by applying extended kantrovich method on these equations, two ordinary differential equations obtained, the two categories combined fixed and simple boundary conditions will be solved by using generalized differential quadrature and in an iterative process system natural frequency is...
Optimal Trajectory Planning for Flight through Microburst Wind Shears
,
M.Sc. Thesis
Sharif University of Technology
;
Pourtakdoost, Hossein
(Supervisor)
Abstract
An optimal trajectory for flight through Microburst wind shears is designed which minimizes the maximum deviation from desired trajectory With respect to optimal control methods. The suitable performance of airplane retrieval in abort landing and landing phases at microburst encounter is achieved by influence of mentioned design in worse case of wind fluctuation and variation. 3D Vicroy microburst model is selected to investigate its effects on 6 DOF jet engine aircraft EOMs. Above optimal control problem is solved using gradient method of SD . Furthermore, sensitivity of optimal trajectory to lateral and longitudinal location of microburst, microburst parameters, throttle setting and...
Quantification Of Seismic Performance Factors Of Steel Plate Shear Wall Systems
, M.Sc. Thesis Sharif University of Technology ; Mofid, Masoud (Supervisor)
Abstract
The AISC Seismic Design Provisions now include capacity design requirements for steel plate shear walls,which consist of thin web plates that infill frames of steel beams, denoted horizontal boundary elements)HBEs), and columns, denoted vertical boundary elements (VBEs). The thin unstiffened web plates are expected to buckle in shear at low load levels and develop tension field action, providing ductility and energy dissipation through tension yielding of the web plate. HBEs are designed for stiffness and strength requirements and are expected to anchor the tension field formation in the web plates. VBEs are designed for yielding of web plates and plastic hinge formation at the ends of the...
Design and Construction of Large-scale Laminar Shear Box for Study of the Behavior of Deep Foundations Subjected to Lateral Loads due to Lateral Spreading using 1-g Shake Table Tests
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohsen (Supervisor)
Abstract
Using appropriate box as an artificial boundary condition is one of the critical tasks in geotechnical physical modeling of the soil mass especially under cyclic loading such as earthquakes. In general there are two types of boxes which can simulate boundary conditions of scaled models as rigid or flexible conditions. Main purpose of this study is design and construction of a flexible box in a way that effects of boundary condition have been minimized during tests. Construction of this box is the first step of an investigation project which concern to evaluate the effect of lateral spreading as a result of liquefaction on deep foundations of bridges, piers, harbors by using shake table test...
Seismic Design of Light Cold-Formed Steel Structures
, M.Sc. Thesis Sharif University of Technology ; Kazemi, Mohammad Taghi (Supervisor)
Abstract
Light cold formed steel structures have a wide use in building constructions and industrial projects due to their economical advantages, rapid erection and installation and capability for industrial mass production. The main objective of this thesis is to investigate the seismic behavior and to study the seismic requirements for design of Light steel frames (LSF) structures. The cold forming technique, and the basic concepts of cold formed steel members design have been investigated and the basic concepts of seismic design of light cold formed steel structures is discussed. In order to investigate the performance of steel strap framed wall systems and estimate its response modification...
Experimental Investigation of Rock Wettability Effect on Carbonate Reservoir Matrix Acidizing
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahaboddin (Supervisor) ; Masihi, Mohsen (Supervisor)
Abstract
Matrix acidizing operation is one of the popular methods of well stimulation in the oil and gas industry which is used to remove near wellbore damage, increase the permeability, hence improve the production rate from the formation. Hydrochloric acid is used in the carbonate reservoirs to remove formation damage and create wormhole deep in the rock. It has been shown that with the proper operating design, significant improvement in the production rate can be obtained. A successful acid operations involves the proper selection of the candidate wells, identify the type of formation damage, stimulation method selection, correct design acidizing scenario, implementation of the technique and...
Development of Dynamic Simple Shear Apparatus for Small Strain Dynamic Tests on Unsaturated Granular Soils by Bender Element and ultrasonic Sensors
, M.Sc. Thesis Sharif University of Technology ; Jafarzadeh, Fardin (Supervisor)
Abstract
Shear modulus and confined modulus are important parameters for static and dynamic analysis in geotechnical applications. Elastoplastic and nonlinear constitutive models has been formulized by these parameters. Cyclic simple shear apparatus had been developed by mounting bender element and ultrasonic sensor to measure continuous shear wave and pressure wave velocities for determination of G_max and M.For this purpose two new pedestals have been fabricated on which HAE ceramic disc and sensors were mounted. A pressure control panel and a hanging column system have been designed to apply high and low matric suction with high accuracy.At first two small strain tests were conducted for...
Investigating Layout of Shear Walls in Tall Buildings with Non-Symmetrical Plan
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
In tall buildings, seismic behavior depends on structural elements and their configuration. The usefulness of shear walls in the structural planning of multistory buildings has long been recognized. When walls are situated in advantageous positions in a building, they can be very efficient in resisting lateral loads originating from wind or earthquakes. Restriction in surrounding effects and the architectural design may contribute to have asymmetry in plan. In a number of papers, published mainly in the last decade, the analysis and design of shear walls has been studied. But just a few of them considered arrangement of shear walls to find the optimum layout. In the present study, analysis...
Study of the Effect of Strip Opening on the Sides of the Steel Plate Shear Wall
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
One of the lateral-load bearing systems that has been recommended since almost 40 years ago is the steel plate shear wall (SPSW) system, which consists of a steel plate surrounded by beams and columns in each story. As for the performance of SPSWs, it is assumed that the boundary members of the wall’s plate, i.e. beams and columns, have sufficient stiffness and strength, so that they would not yield by the tensile stresses exerted due to the post-buckling behavior of the plate (tension field); and the global stability of the structure is still maintained. This assumption leads to significantly increased dimensions of the sections applied in the wall’s boundary members, particularly its...
Linear and Non-linear Dynamic Analysis of Full Scale Shaking Table Laminar Shear Box to Study the Effects of Lateral Spreading Due to Liquefaction on Deep Foundations
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohsen (Supervisor)
Abstract
Liquefaction-induced lateral spreading has imposed severe damages to many important structures supported on pile foundations during past earthquakes. As a result, evaluation of pile response to lateral spreading is an important step towards safe and resistant design of pile foundations against this destructive phenomenon. The boundary conditions for physical modeling in problems of earthquake geotechnical engineering have significant influence on the test results. In order to reduce the undesirable effects of boundaries on the model responses, the flexible containers are used. The flexible containers are those in which the shear stiffness of the walls is proportional to the soil inside. A...
Parametric Study for a Type of Steel Bracing System (Chevron Knee Bracing)on Simple RC Frames
, M.Sc. Thesis Sharif University of Technology ; Mofid, Masoud (Supervisor)
Abstract
In this research, a structural lateral bracing system called ‘Chevron Knee Bracing’ (CKB) on reinforced frames is investigated. This new form of framing system is constructed through the knee and the diagonal brace elements. The diagonal brace component provides the required level of lateral stiffness and stays in the elastic range without buckling at any time. However, the knee part is a fuse-like component that dissipates energy by the formation of plastic flexural and/or shear hinges at its ends and mid-span, when the building is subjected to severe lateral loads. For this purpose, first, by elastic studying of the system, three new and practical parameters are established. Then, the best...
Investigation the behavior of Low-Rise Shear Walls with Smart Rebars
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
In this paper, the response of low-rise shear walls with smart rebars under static lateral loading has been numerically studied, using Finite Element Method. The material used in this study is Shape Memory Alloys (SMAs) which contains nickel and titanium elements. During lateral loading, rebars yield or concrete crushes in compression zone in some parts of the RC shear walls and also residual deflections are created in the structure. The SMA exhibits little residual strains under cycles of loading and unloading even after passing the yielding zone. In addition, SMAs have a good energy dissipation capacity that helps reduce damage while increasing structural capacity. In this study, SMA...
Experimental and Numerical Modeling of Telescopic Damper
, M.Sc. Thesis Sharif University of Technology ; Eskandari, Morteza (Supervisor)
Abstract
This study proposes a new metallic yielding damper for seismic applications. First, considering the damper proposed by curadelli in 2009 a simple lead yielding damper was manufactured to determine its maximum allowable axial deformation showing that it cannot tolerate suitable axial deformations. To solve this problem a telescopic damper with curadelli damper’s descriptions was manufactured and tested which increased the last damper’s allowable deformation 100%. Although new damper’s allowable deformation is twofold the old one, it was not enough for seismic applications. In the next step 6 dampers called lead shear dampers (LSD) with modified lead section were tested. LSD deformation...
Shear Capacity of Ultra-High Performance Concrete Rectangular Beams
, Ph.D. Dissertation Sharif University of Technology ; Joghataie, Abdolreza (Supervisor)
Abstract
The application of ultra-high performance concrete (UHPC) as an alternative to conventional/ normal concrete (NC) has grown rapidly in recent years. However, there is limited knowledge on its shear behavior, which is essential for developing design guidelines for structural applications. A detailed parametric study was conducted on 38 beam specimens, half of which were made of UHPC and the other half made of NC. To ensure applicability of findings, two types of UHPC mixes were used, a proprietary and a generic mix. Eighteen of the beams were prepared and tested in Tabriz, Iran, while the other 20 were made and tested in Miami, FL. Test parameters included type of concrete (UHPC and NC),...