Theses and Dissertations at Montana State University (MSU)
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Item Predicting and modeling the material properties of fused deposition modeling elements leading to more efficient structural designs(Montana State University - Bozeman, College of Engineering, 2021) Murray, Flynn Rae; Chairperson, Graduate Committee: Michael BerryThe current construction industry has a significant negative impact on the climate, and this impact is expected to increase as the world's population continues to grow and urbanization expands. This impact may be reduced by implementing more sustainable building materials and practices. The primary objective of this research is to develop a methodology to estimate and model the material/structural response of elements made with fused deposition modeling. This will ultimately lead to an increased use of FDM in structural applications, and open the door to combining FDM with topology optimization to design and build optimized structural elements, resulting in a more sustainable infrastructure. In this research, tensile and flexural specimens printed in a variety of orientations were tested to evaluate/quantify the effects that print orientation have on elastic properties, ultimate stresses, and failure mechanisms of FDM parts. These elastic properties were then implemented into an orthotropic formulation of the Generalized Hooke's Law, and successfully used in finite element models to predict the elastic response of FDM specimens. Based on this analysis, it was determined that, while the Generalized Hooke's Law provided some advantages, the elastic material response of FDM parts could be estimated with a simpler isotropic model with little loss of accuracy. Response Surface Methodology (RSM) was then successfully used to further evaluate/quantify the effects that print orientation and scale have on the behavior of FDM parts, and to develop equations to predict the stiffness and strength of FDM parts given these print parameters. Finally, the feasibility of using topology optimization combined with additive manufacturing is briefly investigated.Item Assessment of district energy integration between buildings(Montana State University - Bozeman, College of Engineering, 2021) Oladeji, Oladayo; Chairperson, Graduate Committee: Kevin AmendeDistrict heating or cooling is a system for distributing heat or chilled water in a centralized location through various systems which is intended for residential and commercial heating or cooling requirements. Montana State University (MSU) is looking at implementing a future energy district in form of a distributed heat pump model. Implementing such system will help in reducing carbon emissions in the atmosphere, provide energy savings and ensuring energy is being used efficiently. In the summer season, there is a lack of substantial heat sinks in which heat could be utilized and in the winter season there is a lack of substantial heat sources available due to the extreme cold weather. This project identifies systems that serves as heat sinks and sources in buildings and provides substantial energy. This project also looks into the feasibility of connecting such systems together in a building to follow a recirculating heat pump model which operates in the temperature range of 60°F - 90°F. If this model provides much energy saving opportunities, it could be incorporated in buildings on campus here at MSU and connected to the future energy district. The project scope was limited to Barnard Hall, in which heat sources opportunities identified include the building exhaust air system and the process cooling system while heat sink opportunities identified include the domestic hot water system and the outdoor air that needs to be pre heated majority of the time in Bozeman, Montana. Energy calculations were done for each system and imputed into TRNSYS, an extremely flexible graphically based software used to simulate the behavior of transient systems. The heat pump model was then designed and simulated for a time frame of 8760 hours (A year). The researched showed that this provided some energy savings opportunities and yields no profit in general.Item Controlling the area expansion of a backwards centrifugal fan blade passage using the principles of a diffuser and computational fluid dynamics(Montana State University - Bozeman, College of Engineering, 2021) Michalson, Adam Jeffrey; Chairperson, Graduate Committee: Erick JohnsonCentrifugal Fans are widespread in today's modern built environment. While a few variations of these fans exist, backward centrifugal fans are an efficient economical option capable of producing the pressure and airflow required for many modern building systems. Even though fans have become necessary piece of building engineering to facilitate occupant health and comfort, fan design almost exclusively relies on approximations to equations that have not changed since the 1950s and can consume, on average, 15% of a building's electrical consumption. Additionally, the approximations made support the ease and low cost of manufacturability. The traditional centrifugal fan design is made from stamped metal parts creating a fan blade sandwich with the blades held between an inlet shroud and a backplate. This rectangular blade passage is where the fluid flows through and picks up tangential acceleration. However, since the 1950s, nearly all advancements in fan design have been through incremental changes that are made by individual companies, and these resulting designs and performance data remain proprietary. This research revisits the foundations of centrifugal fan design with more modern tools and utilizes the concept of the diffuser to strictly control the expansion of the blade passage to improve centrifugal fan efficiency. Computational fluid dynamics was used to evaluate the performance of the new design against a traditionally manufactured fan. Combining the diffuser concept with an elliptical profile for the blade passage better controls the uniformity of the velocity field and pressure gradients through the passageway, while also reducing turbulence. Simulations of the new design against the traditional approach to fan design show an increase of nearly 10% in total efficiency.Item Energy modeling development and calibration for a mini district energy loop assessment comprised of a set of campus buildings(Montana State University - Bozeman, College of Engineering, 2019) Hays, Joshua Koplyay; Chairperson, Graduate Committee: Kevin AmendeDistrict energy loops are comprised of a network of buildings connected in a water-source loop with utilization of heat pumps to allow for buildings to share thermal energy. To assess the feasibility of creating a district energy loop, the heat sharing capabilities of the proposed interconnected buildings needs to be analyzed. This paper develops a method to assess a mini-district energy loop from historical utility data. Energy modeling was used to create a simple building model from building construction specifications and given inputs from the University Services Engineers on Montana State University's campus. With the energy model developed, the historical utility data was compared to the hourly heat demand and electricity consumption for the building on an outdoor temperature basis. Calibration techniques for heat demand were comprised of increasing or decreasing the outdoor air ventilation requirement and the base heat demand. Electricity consumption was calibrated by altering the equipment plug load in the spaces. The simulated data was validated with metered hourly heat demand data for a high-energy use laboratory building on MSU's campus. This simple energy model was reconfigured to represent another building at MSU by altering building envelope dimensions, and then re-applying calibration techniques to generate hourly heating and cooling data. Converting the model to be heat-pump compatible allowed for internal thermal energy sharing within the building to occur. Hourly heat demand and hourly heat availability were determined for external thermal energy sharing for a high-energy use laboratory building. After which, heat sources, heat sinks, and thermal energy storage tanks were assessed to determine the feasibility of a district energy loop.Item Experimental and analytical investigation of masonry infill and confined masonry wall assemblies(Montana State University - Bozeman, College of Engineering, 2017) Johnson, Maxim Gordon; Chairperson, Graduate Committee: Damon FickMasonry has the benefit of strength and ease of construction but lacks the ability to resist lateral forces due to its brittle nature. However, with the addition of concrete confining frames to plain masonry walls, additional strength and ductility can be attained. Two such confinement systems include masonry infill and confined masonry walls. Currently, masonry infill assemblies are the most common form of lateral force resisting systems in countries where access to more traditional concrete and steel materials is limited. However, recent studies have stated that confined masonry provides improved performance because of the bond between the concrete and brick. This thesis presents an investigation of the behavior of both types of concrete confinement methods and identifies advantages of each system with regards to strength, ductility, and performance during strong ground motion events. To accomplish this objective, 1/3-scale specimens were constructed and tested in direct shear to determine the load-displacement response for both masonry infill and confined masonry walls and compared with results of each type of concrete confinement technique as compared to a plain masonry specimen. The masonry infill wall strength was 35% larger and deflected ten times more than the plain masonry wall at peak load. The confined masonry showed 80% more strength capacity; however, only deflected 2.5 times more than the plain masonry wall at peak load. The test results were incorporated into analytical models that approximated the load displacement response observed during the tests. The models were used to perform a nonlinear push-over analysis on a reduced scale 5-story building damaged by the Nepal earthquake. The first story walls of the confined masonry model failed at a base shear that was 27% larger than the masonry infill model. First story drifts were 64% larger in the masonry infill model. This supports the general observation that each wall has merit in a specific design scenario. Masonry infill walls may be preferred in for designs where energy dissipation may be critical. On the strength side, confined masonry walls may be preferred where strength is preferred over ductility.Item Comparative analysis of a design tool to field study data for an unglazed transpired solar collector(Montana State University - Bozeman, College of Engineering, 2016) Guenette, Chelsea Lynn; Chairperson, Graduate Committee: Kevin AmendeEnergy consumption and emission concerns have come to the forefront of political and public attention. The adoption of building energy standards such as ASHRAE Standard 90.1 have helped guide the building industry by setting increasingly stringent building energy performance requirements. In order to meet these ever increasing energy standards, research and development of energy efficient technologies have become a priority. One of these is the unglazed transpired solar collector (UTSC) which is particularly useful in sunny, cold climates such as Bozeman, Montana. This research intends to bridge the gap between theoretical models and field studies by comparing an accepted UTSC model within a commercially available energy modeling software -- EnergyPlus -- to experimental data collected at Jabs Hall in Bozeman, Montana. An energy model was created to represent a UTSC and its associated building in a commercially available software. Weather and operating data for the UTSC was collected on site. The collected weather data was used to create a custom input weather file for the energy model. The collected operational data was used to characterize the UTSC performance and compare to the energy model results. Limitations for both the energy and data acquisition make it difficult for the results to be compared directly. However, conclusions were drawn about UTSC integration into building systems.Item Curvature ductility of reinforced and prestressed concrete columns(Montana State University - Bozeman, College of Engineering, 1984) Suprenant, Bruce AlanEngineers are concerned with the survival of reinforced and prestressed concrete columns during earthquakes. The prediction of column survival can be deduced from moment-curvature curves of the column section. An analytical approach is incorporated into a computer model. The computer program is based on assumed stress-strain relations for confined and unconfined concrete, nonprestressed and prestressing steel. The results of studies on reinforced and prestressed concrete columns indicate that reinforced concrete columns may be designed to resist earthquakes, while prestressed concrete columns may not. The initial reduction in moment capacity, after concrete cover spalling, of a prestressed concrete column could be as much as 50%. Analyses indicate that the bond between concrete and prestressing strand after concrete cover spalling is not critical.Item Numerical analysis of blast loaded civilian structures(Montana State University - Bozeman, College of Engineering, 2000) Lutzenberger, Bert JeffreyItem Research on earthquake resistant structures(Montana State University - Bozeman, College of Engineering, 1949) Markellis, Constantine A.Item The evolution of the cultural landscape in Yellowstone National Park's Upper Geyser Basin and the changing visitor experience, 1872-1990(Montana State University - Bozeman, College of Letters & Science, 1995) Byrand, Karl John