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Full-Text Articles in Engineering
Fatigue-Induced Failure In Horizontal-Axis Wind-Turbine (Hawt) Blades And Hawt Drivetrain Gears, Varun Chenna
Fatigue-Induced Failure In Horizontal-Axis Wind-Turbine (Hawt) Blades And Hawt Drivetrain Gears, Varun Chenna
All Theses
Wind energy is one of the most promising and the fastest growing installed alternative-energy production technologies. In fact, it is anticipated that by 2030, at least 20% of the U.S. energy needs will be met by various onshore and offshore wind-farms [a collection of wind-turbines (converters of wind energy into electrical energy) at the same location]. A majority of wind turbines nowadays fall into the class of the so-called Horizontal Axis Wind Turbines (HAWTs). Turbine blades and the gearbox are perhaps the most critical components/subsystems in the present designs of HAWTs. The combination of high failure rates (particularly those associated …
Numerical And Reliability Analysis Of Gravity Cantilever Retaining Walls Backfilled With Shredded Tires Subjected To Seismic Loads, Eleanor Huggins
Numerical And Reliability Analysis Of Gravity Cantilever Retaining Walls Backfilled With Shredded Tires Subjected To Seismic Loads, Eleanor Huggins
All Theses
Shredded tires have been considered as a suitable alternative to conventional sand and gravel backfill materials as they offer benefits from their significantly lower unit weight, reductions in the cost of materials and construction, and because they utilize a common and potentially hazardous waste material. This research addresses some gaps in previous research in the implementation of shredded tires in this capacity by examining variation in material properties through a reliability analysis, developing an improved design technique for retaining walls tailored to shredded tire fills, and simulating how shredded tire backfill behaves in conjunction with retaining walls when subject to …
Friction Stir Welding (Fsw) Process Modeling And Fsw Joint Design For Blast Survivable Structures, Anand Hariharan
Friction Stir Welding (Fsw) Process Modeling And Fsw Joint Design For Blast Survivable Structures, Anand Hariharan
All Theses
In order to satisfy the need for better ballistic performance against lethal threats, new grades of Titanium (e.g. Ti-6Al-4V) and Aluminum (e.g. AA5083) alloys are being employed in the design of blast survivable structures. These better performing alloys are not readily amenable to conventional welding process or result in inferior welds when joined using conventional welding process. On the other hand, Friction Stir Welding (FSW), a relatively new welding process, has been found to be successful in producing good quality welds in these alloys. FSW also offers better weld performance in comparison with the conventional welding process. But the methodology …
Kinetic And Finite Element Modeling For Firing Brick, Daniel Mckinney
Kinetic And Finite Element Modeling For Firing Brick, Daniel Mckinney
All Theses
Kinetic modeling and simulation were used to optimize the firing cycle for brick. This was done to develop a tool for the brick industry to reduce fuel consumption and emissions during firing. A kinetic model was built using shrinkage data from dilatometer measurements and mass loss data from thermogravimetry measurements in order to predict the density as a function of temperature and time. The density of brick was related to the absorption coefficient (C/B), an ASTM standard which is related to the durability of the brick. The kinetic model was used to optimize the firing curve using a rate controlled …
Friction Stir Welding Process And Material Microstructure Evolution Modeling In 2000 And 5000 Series Of Aluminum Alloys, Harshavardhan Yalavarthy
Friction Stir Welding Process And Material Microstructure Evolution Modeling In 2000 And 5000 Series Of Aluminum Alloys, Harshavardhan Yalavarthy
All Theses
Interactions between the rotating and advancing pin-shaped tool (terminated at one end with a circular-cylindrical shoulder) with the clamped welding-plates and the associated material and heat transport during a Friction Stir Welding (FSW) process are studied computationally using a fully-coupled thermo-mechanical finite-element analysis. To surmount potential numerical problems associated with extensive mesh distortions/entanglement, an Arbitrary Lagrangian Eulerian (ALE) formulation was used which enabled adaptive re-meshing (to ensure the continuing presence of a high-quality mesh) while allowing full tracking of the material free surfaces. To demonstrate the utility of the present computational approach, the analysis is applied to the cases of …
Use Of Orthogonal Arrays For Efficient Evaluation Of Geometric Designs For Reducing Vibration Of A Non-Pneumatic Wheel During High-Speed Rolling, William Rutherford
Use Of Orthogonal Arrays For Efficient Evaluation Of Geometric Designs For Reducing Vibration Of A Non-Pneumatic Wheel During High-Speed Rolling, William Rutherford
All Theses
During high speed rolling of a non-pneumatic wheel, vibration may be produced by the interaction of collapsible spokes with a shear deformable ring as they enter the contact region, buckle and then snap back into a state of tension. In the present work, a 2D planar finite element model with geometric nonlinearity and explicit time-stepping is used to simulate rolling of the non-pneumatic wheel. Vibration characteristics are measured from the FFT frequency spectrum of the time-signals of perpendicular distance of marker nodes from the virtual plane of the spoke, thickness change in the ring between spokes, and ground reaction forces. …