Sharif Digital Repository

In this thesis, the behavior of cold-form steel (CFS) frames equipped with various configurations of steel sheathing and K-shaped braces is experimentally investigated. Low lateral resistance is the main deficiency of the CFS shear walls. Despite their advantages, such as being lightweight, ease of fabrication, and an environmentally friendly system, their lack of adequate lateral strength prevents engineers from widely using them, especially in areas with medium to high seismicity or in mid-rise buildings. In this regard, a total of seven full-scale specimens with different configurations of steel sheathing and k-braced, with and without cladding, were tested to investigate their seismic... 

The objective of this paper is to explore and characterize the effect of practical construction details on the dynamic and gravity load carrying capacity of cold-formed steel framed shear walls sheathed with Oriented Strand Board (OSB). In order to improve the lateral stiffness and shear strength of cold-formed steel (CFS) framing wall, an innovative CFS wall equipped with OSB and gypsum boards are experimentally studied in this thesis. For this purpose, six K-braced frames with and without sheathing boards are investigated experimentally under lateral cyclic loading and gravity forces. The failure modes, loaddisplacement responses, and energy absorption capacity of the specimens were... 

Focusing on developing the EEPS (Energy Electric and Power System) based on the SG (Smart Grid) infrastructure to achieve implementation of EI (Energy Internet) ultimately, in order to analyze and manage the energy/power consumption, requires a robust embedded EMS (Energy Management System) to implement real-time LF (Load Forecasting), prevent the power waste and realize consumption management which eventually leads toward the smart industries/buildings. STLF (Short Term Load Forecasting) is an essential component that an industrial plant requires to manage the power, regarding the load fluctuations during production, and compulsory requirement of cost mitigation. This thesis, in order to... 

In the first part of this work, citric acid monomer was selected to produce dendrimer through the divergent method using logical conditions (for controlling its functional groups) on the base of poly (ethylene glycol) as the core. Triblock copolymers (ABA-type) of citric acid and poly (ethylene glycol) (PCA-PEG-PCA) as biocompatible compounds were synthesized in four different molecular weights and applied as nanocarriers. The structure definition of the molecules and nanoparticles were carried out using different spectroscopy methods. Diameter of the synthesized copolymers was investigated using dynamic light scattering (DLS) experiments and transmission electron microscopy (TEM) and it was... 

In this thesis, the behavior of proposed moment resisting precast beam-column concrete connection under cyclic and monotonic loads is investigated. In this study, the finite element models of precast and monolithic middle and corner connections are created. The results of finite element analysis under cyclic loading is verified with existing experimental results based on failure mode, ductility, energy dissipation capacity and flexural strength. Based on the results of nonlinear finite element analysis, the analytical behavior of samples is in good agreement with experimental results and finite element analysis of proposed precast connection can be replaced with supplementary tests. Then the... 

A tsunami is a series of tides most commonly caused by the deformation of the sea floor during a submarine earthquake. They are extremely long waves with the distance between successive peaks or troughs on the order of 10’s to 100’s of miles. They are also generated by landslides, volcanic eruptions or more rarely by asteroid impact. These causes change in location on the surface of the water which in turn creates numerous waves that spread out from the zone of turbulence. Few current design codes for coastal structures include tsunami. Even those that do, the bases for taking the hydrodynamic loads into the design are often grossly simplified and may be overly conservation and/or... 

Bones adapt their form and structure to make an efficient use of their mass against the applied mechanical loads. So, it is not surprising to assume that the geometry and density distribution of a bone contains information about its loading history. The objective of this work was to develop a framework to simulate the bone remodeling procedure as a topology optimization process and then use this framework to develop a simple technique for estimating the dominant joint loads based on the bone’s density distribution.
At first, the remodeling equation was derived from the structural optimization task of minimizing the strain energy in each time step, using the level set method. Employment... 

Regarding complexity and wide range use of distribution network structures, loss reduction is possible in case of complete knowledge and suitable approaches. Loss reduction not only can grow GDP but also can improve economic growth. It should have schedule and plan wisely. Thus, in this research, first a region called Yusef Abad in Tehran was selected then the network was assessed completely. During the assessment, the research team determines causes of energy loss and load loss and then measured amount of each one. Then, the loss share of each element of the network determined. Elements of the network consist of transformers, conductors and meters. Then possible solutions for loss reduction... 

The purpose of this project is the analysis of free and forced vibrations of sandwich panels under moving loads. In order to analyze the problem, sandwich panels are modeled as composite square plates. By using third order shear deformation theory, equations of motion are derived. Equations of motion with six different boundary conditions are solved utilizing generalized differential quadrature method. Natural frequencies are obtained for simple cases reported in the literature.In addition, a sandwich panel under moving load with simply supported boundary conditions is analyzed and time series response of the middle point is obtained. The time series response is also studied parametrically... 

Purpose of ongoing thesis is providing a tool for suitable modeling, increase efficiency and decrease construction cost of solar absorption heat pump. At first, the solar absorption heat pump is modeled by the thermodynamic laws. Then, this model is converted to the new standard mathematical programming model using exergy and thermodynamic Analysis with considering all technical and economic constrains. This mathematical model is optimized by Genetic algorithm (GA). Because of the nonlinear objective function and the constraint, GA is used as optimization algorithm. After applying GA, optimized parameters of cycle heat exchanger designing and its electricity consumption are calculated.... 

Dynamic compaction is a widely used soil deep improvement method in dry and/or saturated soils. Despite its vast application, numerical and /or experimental modeling studies of dynamic compaction due to impact are little. In order to clarify the ambiguities in process and to present a comprehensive design approach, numerical modeling of dynamic compaction in dry soils with PISA (A fully coupled dynamic finite element code: Program for Incremental Stress Analysis) has been done. Because the geometry and loading configuration are symmetric around the falling tamper (load centerline), a two-dimensional axisymmetric simulation has been used. Here for sake of simplicity, initial velocity of... 

Worldwide interoperability for Microwave Access (WiMAX) is one of the most dominant cell-based broadband wireless metropolitan access technologies. Packet scheduling algorithm specifies the packet transmission order. In WiMAX standard, packet scheduling algorithm is not defined and its efficient design is left for developers and researchers. The existing researches in the scope of uplink packet scheduling, which is the most challenging packet scheduling scheme, consider only one cell. However the uplink available resources might not be enough when there are many packets that should be scheduled. To solve this problem, we propose an algorithm that uses the load balancing mechanisms that are... 

Building simple and effective models are essential to many applications, such as building performance diagnosis and optimal control. Detailed physical models are time consuming and often not cost-effective. Black box models require large amount of training data and may not always reflect the physical behaviors. In this study, a method is proposed to simplify the building thermal model and to identify the parameters of the simplified model. For instance, predicting the next-24-hour load in a building is essential for the optimal control of heating, ventilating and air-conditioning (HVAC) systems that use thermal or cool storage technology. In the first phase of this study, equations for... 

In the ongoing research project on tall buildings, the study of wind-induced demands is categorized as: along-wind and crosswind responses. These demands are caused by different mechanisms. Moving along the wind-induced is due to the effects of turbulence impact while the perpendicular component is related to the effects of windstorm. Along-wind response may be of special importance with respect to the comfort criteria. The loading condition on skyscrapers may differ from low-rise buildings due to the number of stories, on structures due to the high number of stories, and the importance of dynamic effects of current loading (wind). On the other hand the effect of wind load on tall structures... 

Assessment of existing jacket type offshore platform against environmental wave loading hazard is the central component of this work. Two general approaches exist in this context, deterministic and probabilistic assessment. In this study, a new probabilistic method (reliability analysis) to assess offshore structures under environmental loading (extreme wave) is introduced. Before describing this approach, several necessary elements such as collapse analysis, sampling methods and wave hazard analysis should be investigated. First of all, deterministic assessment of SPD2 platform located in Persian Gulf, which is the case study considered in this dissertation, is conducted utilizing... 

Nonlinear dynamic procedure (NDP) can in general provide more realistic results than nonlinear static procedures (NSPs). That is due to consideration of higher modes effects and the shifts in inertia load patterns as the structural system experiences nonlinear behavior. Therefore, the simplified NSPs based on constant load patterns are inadequate to determine the inelastic seismic demands especially for top stories of tall buildings. The conventional procedures that have been implemented in design codes and guidelines such as ATC-40, FEMA356, FEMA440 and ASCE41-06, apply invariant load patterns such as inverse triangular, equal lateral force (ELF), first mode shape, uniform and SRSS modal... 

In this thesis one of the sensorless methods which exploits the existing anisotropies of the rotor is utilized to estimate rotor position. In order to implement this method, first a high frequency voltage is injected in a specific, time-varying direction and then the corresponding current response would be observed in order to estimate the rotor saliency position. The estimation of rotor position would be more precise as the magnetic anisotropy due to rotor saliency increases and as a result the effect of noise and different disturbances in estimation of rotor position would be decresed. The effect of stator resistence is one of these disturbances which is usually neglected as a result of... 

In the present study, an analytical solution is developed to calculate the interlaminar stresses in long symmetric laminated composite plates subjected to shearing load. At first, upon the successive integrations of the strain-displacement relations and using the existing patterns in deformation of a long symmetric 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... 

Numerous research is available in the literature regarding shear walls. These have considered parameters like wall cross-section, Reinforcement configuration, boundary elements, etc. In addition, seismic and wind loading behavior has been discussed. Currently, the software ETABS is used extensively in automatic design of shear walls, The programs design bases are investigated in this thesis in ragards to flexural, shear and boundary elements of shear walls under seismic loading. The attachment of wall elements to frame (column) elements is of particular interest in this study  

Laufer and Hulstijn (2001) proposed the Task-Induced Involvement Load Hypothesis stating that in the retention of new words in an incidental context, tasks with higher involvement load will be more effective than tasks with lower involvement load. The present study aimed to examine whether the retention of vocabulary is enhanced with an increase in the amount of task-induced involvement load in an intentional learning environment. Moreover, it was investigated whether proficiency level of learners had a role in the effectiveness of the vocabulary tasks with different involvement loads. Four groups of university students, male and female, participated in the study. They were given a TOEFL...