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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

EFFECT OF BUILDING ORIENTATION ON STRUCTURAL RESPONSE OF REINFORCED CONCRETE MOMENT RESISTING FRAME STRUCTURES

Parsa, Amanullah 01 May 2020 (has links)
In time history analysis of structures, the geometric mean of two orthogonal horizontal components of ground motion in the as-recorded direction of sensors, have been used as measure of ground motion intensity prior to the 2009 NEHRP provision. The 2009 NEHRP Provisions and accordingly the seismic design provisions of the ASCE/SEI 7-10, modified the definition of ground motion intensity measure from geometric mean to the maximum direction ground motion, corresponding to the direction that results in peak response of the oscillator. Maximum direction response spectra are assumed to envelope the range of maximum possible responses over all nonredundant rotation angles. Two assumptions are made in the use maximum ground motion as the intensity measure: (1) the structure’s strength and stiffness properties are identical in all directions and (2) azimuth of the maximum spectral acceleration coincides with the one of the principal axes of the structure. The implications of these assumptions are examined in this study, using 3D computer models of multi-story structures having symmetric and asymmetric layouts and elastic vibration period of 0.2 second and 1.0 second subjected to a set of 25 ground-motion pairs recorded at a distance of more than 20 km from the fault. The influence of the ground-motion rotation angle on structural response (here lateral displacement and story drift) is examined to form benchmarks for evaluating the use of the maximum direction (MD) ground motions. The results of this study suggest that while MD ground motions do not always result in largest structural response, they tend to produce larger response than the as-recorded ground motions. On the other hand, more research on non-linear seismic time history analysis is recommended, especially for asymmetric layout plan buildings.
2

Assessing Thermal Comfort Conditions / A Case Study On The Metu Faculty Of Architecture Building

Cakir, Cagri 01 December 2006 (has links) (PDF)
The aim of this study was to evaluate the effects of environmental design parameters on thermal comfort conditions in the METU Faculty of Architecture Building located in Ankara. The building had some problems in terms of indoor climatic conditions, both in winter and in summer. It was evident that some design parameters caused this undesirable situation. The study therefore focused on understanding and evaluating the effects of design-dependent elements such as thermal mass, the size and orientation of windows, shading and vegetation on thermal comfort conditions in the case study building. While conducting this study, data loggers were used to record temperature and humidity data in predetermined rooms. Data was collected during certain periods in July, August, and September 2006. The data collected was analyzed statistically and hypotheses were tested using ANOVA. This study showed that the effect of thermal mass was almost the same for the rooms investigated owing to the fact that the entire building had been constructed with concrete curtain walls. In terms of thermal performance the number and orientation of the exterior walls, orientation and size of windows, room heights and also sun shading with surrounding vegetation were most effective design parameters for the rooms investigated
3

The impact of building orientation on energy usage : Using simulation software IDA ICE 4.7.1

Martin, Daniel January 2017 (has links)
The building sector consumes 32% of global energy used, and it is responsible for 20% of total greenhouse gases emissions. In Europe, more than one third of the buildings are 50 years or older, thus, it is critical that new dwellings are designed in the most efficient way from an energy perspective, since the consequences of the decisions taken today will remain during decades. The use of Building Information Modeling (BIM) software is promising for the design of a wide range of constructions; from small dwellings to big apartment buildings. These programs allow the architect, designer or civil consultant to perform several simulations of the energy behavior of a building in a timely manner, even before a single brick is put in place. Among them, IDA ICE software utilized in this thesis is a top rated program, situated by some authors within the four main building energy simulation tools. This is an outstanding fact considering that it is estimated in more than 400 the number of available BIM programs. With the help of IDA ICE it will be demonstrated that for a dwelling object of study, located in Madrid (Spain), it is possible to save up to 4 250€ through the entire life of the building if the proper orientation is chosen. The discussed literature and results will also show that orientation is, by far, the most critical passive design parameter related to a building, from which the efficacy of other related measures depends on.   It will be also proven that the optimal orientation depends on the weather where the dwelling is located, even though a general trend consisting in orienting the houses located in the northern hemisphere to the south, and vice versa, is observed. Building orientation, BIM programs, building energy consumption, passive design parameters, IDA-ICE simulation tool.
4

Contribution à l’amélioration de la prise en compte des spécificités des procédés de fabrication additive en conception : application à la qualité de surface. / Contribution to the enhancement to take into consideration the particularities of additive manufacturing in design : application to surface quality.

Ga, Bastien 02 December 2019 (has links)
La FA (Fabrication Additive) est un procédé de fabrication qui rend possible, en ajoutant de la matière couche après couche, la création de pièces en trois dimensions. Cette technologie a de nombreux intérêts car elle permet l’intégration de formes ou de structures complexes, la réduction des déchets, la fabrication sur demande et la réduction du temps de conception. Au cours de cette thèse, nous avons cherché à déterminer des orientations remarquables de pièces afin de les fabriquer par des procédés de FA. Au vu du grand nombre d’effets liés à l’orientation d’une pièce, nous avons choisi une approche multicritères prenant en compte la qualité de surface des pièces, le volume de support, le temps et le coût de fabrication. Afin d’avoir une bonne qualité de surface sur les faces fonctionnelles de la pièce et pour limiter le post-traitement, une orientation précise a été définie pour chacune d’elle. Cette méthodologie a été développée dans le cadre du projet Taal, projet de recherche et développement précurseur du logiciel 4D-Additive de Coretechnologie. Sur ce dernier, en plus de cette méthodologie, de nombreuses fonctions ont été développées pour préparer la fabrication d’une pièce par un procédé additif. L’orientation d’une pièce en FA est une étape à ne surtout pas négliger. Elle pourra permettre de trouver un compromis entre les spécificités liées aux procédés de FA ou entrainer un coût important de fabrication et une qualité de surface de la pièce médiocre. Des évolutions de la méthode sont possibles comme une étude mécanique de la pièce dans les différentes orientations testées car de nombreuses questions se posent sur la résistance des pièces imprimées. / AM (Additive Manufacturing) is a manufacturing process that makes possible, by adding layer-by-layer material, to create three-dimensional parts. This technology has many interests as it allows complex shapes or structures integration, waste reduction, on-demand fabrication and reduced conception time. During this thesis, we tried to determine remarkable orientations of parts in order to manufacture them by AM process. Considering the large number of effects related to part orientation, we chose a multi-criteria approach taking into account the surface quality of the parts, the volume of support, the manufacturing time and cost. In order to have a good surface quality on functional faces of the part and to limit the post-treatment, a precise orientation has been defined. This methodology was developed in the structure of the Taal project, a research and development project precursor of Coretechnologie's 4D-Additive software. On this last, in addition to this methodology, many functions have been developed to prepare the manufacture of a part by an additive process. The orientation of a part in AM is a step that can’t be overlooked. It may make it possible to find a compromise between the specificities related to the AM processes or generate a high manufacturing cost and a poor surface quality of the part. Evolutions of the method are possible as a mechanical study of the part in the different orientations tested because many questions arise on the strength of the printed parts.
5

Parametric study of energy retrofit options for a historical building

El Tayara, Khaled January 2022 (has links)
Retrofitting measures in old buildings aimed at reducing energy consumption has become a widespread subject and an urgent matter to counteract the effects of climate change and GHGs emissions. The globe has reaffirmed its agreement taken in COP21 to reduce emissions in COP26. The building sector is one of the culprits with a 70 % future energy consumption forecasted by 2050 i.e., the year certain countries aim to carbon neutral (e.g., Sweden). An old building with a severe problem of energy leakage has been studied under the influence of multiple parameters such as building orientation, shading systems, location, Low-E film and an alternative energy supply (GHP). The original building’s EnU amounted to 194.5 kWh/m2•yr; the parameters were applied and orientation of 90⁰ worked best, if the building was being designed, contrary to this case. However, energy reductions, compared to the base model, were actually achieved with the application of Low-E (5%) films and when substituting the heating demand with a GHP (57.5%), LEF-GHP reached (59.2%) and a corresponding decrease in CO2 emissions. Thermal comfort was best achieved with models that had the highest energy consumption such as LEF and ES making it counterproductive in fulfilling the aim of reducing GHG footprint of Rådhuset. The economic feasibility study showed that the installation of a GHP with at least the COP of 4.0 would lead to a shorter payback period than solely applying LEF. A tailored solution of a change in the energy source such as electrified heat supply from renewables combined with LEFs would reduce the energy and emission impact of any building; this would help the building sector reach the envisioned goal of carbon neutrality in 2050.
6

Low energy air conditioning for hot climates

Almutairi, Hamad Hhn January 2012 (has links)
Fossil fuels are the major sources of electrical power generation in the world. Among all fossil fuels, oil is considered as the most sought-after fuel. The burden on countries that provide subsidized electricity produced from oil-fired power plants is noteworthy. Kuwait is a notable example of these countries. Electricity in Kuwait is heavily consumed by residential air conditioning, which comprises 60% of the total electricity generated at peak times on a hot summer day. From this perspective, residential air conditioning in Kuwait was selected to undergo further investigation regarding low energy air conditioning choices. Three solutions to control the rapid growth of demand for electricity by residential air conditioning are examined. The first solution investigated assesses the orientation and grouping of houses in Kuwait in order to examine their effect on cooling load and electrical energy consumption for future houses. Four residential cases were developed; each case comprises six typical houses. The cases identified are: (1) single block facing east-west, (2) single block facing north-south, (3) double block facing east-west and (4) double block facing north-south. Cooling loads are calculated using the DesignBuilder building thermal simulation software. Case (2) is found to have the smallest cooling load, and case (1) the largest. The estimated savings from applying case (2) compared to the average of the four cases for the future houses planned to be built by the government by the year 2016 (i.e. approximately 20,000 houses) are found to be approximately .US 33 million of power system capital costs, 15 GWh per year of electrical energy consumption and 11 kilotons per year of CO2 emissions. In the second solution, a lifecycle cost analysis is performed to evaluate the economic feasibilities of electricity driven chilled water system compared to predominant air conditioning system in Kuwaiti houses which is Packaged- Direct Expansion. The study considers the total cash paid by the consumer and the total cash paid by the government, since electricity is subsidized in Kuwait. The study finds that the chilled water system is not cost-effective for consumers due to high installation cost. However, a chilled water system would be cost-effective for the government because it consumes 40%less electrical energy than Packaged-DX. So, the study suggests subsidising the installation of chilled water systems so that the installation cost to the consumer is the same as for Packaged-DX systems. In the third solution, the study examines the viability of a single-effect LiBr absorption chiller driven by steam extracted from the steam turbine in the configuration of a combined cycle power plant (CCPP). The analysis shows that CCPP with absorption chiller yields less net electrical power available to utility grid compared to similar CCPP giving electricity to the grid and to Direct-Expansion air conditioning systems for the same cooling requirements. The reasons for that are the reduction in steam turbine power output resulted from steam extraction, and the amount of electrical energy required to operate the configuration of CCPP with absorption chiller.

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