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Application And Evaluation Of Full-Field Surrogate Models In Engineering Design Space Exploration, Christopher Murray Thelin
Application And Evaluation Of Full-Field Surrogate Models In Engineering Design Space Exploration, Christopher Murray Thelin
Theses and Dissertations
When designing an engineering part, better decisions are made by exploring the entire space of design variations. This design space exploration (DSE) may be accomplished manually or via optimization. In engineering, evaluating a design during DSE often consists of running expensive simulations, such as finite element analysis (FEA) in order to understand the structural response to design changes. The computational cost of these simulations can make thorough DSE infeasible, and only a relatively small subset of the designs are explored. Surrogate models have been used to make cheap predictions of certain simulation results. Commonly, these models only predict single values …
Ligament Model Fidelity In Finite Element Analysis Of The Human Lumbar Spine, Mitchell Scott Hortin
Ligament Model Fidelity In Finite Element Analysis Of The Human Lumbar Spine, Mitchell Scott Hortin
Theses and Dissertations
The purpose of this project is to quantify the effects of increasing spinal ligament fidelity on the mechanics of the human lumbar spine using finite element analysis (FEA). In support of this goal, a material characterization study was completed to provide anisotropic, nonlinear material parameters for the human anterior longitudinal ligament. (ALL). Cadaveric samples of the human ALL were tested using a punch test technique. Multi- axial force-deformation data were gathered and fit to a commonly used transversely isotropic material model using an FEA system identification routine. The resulting material parameters produced a curve that correlated well with the experimental …
Developing An Architecture Framework For Cloud-Based, Multi-User, Finite Element Pre-Processing, Jared Calvin Briggs
Developing An Architecture Framework For Cloud-Based, Multi-User, Finite Element Pre-Processing, Jared Calvin Briggs
Theses and Dissertations
This research proposes an architecture for a cloud-based, multi-user FEA pre-processing system, where multiple engineers can access and operate on the same model in a parallel environment. A prototype is discussed and tested, the results of which show that a multi-user preprocessor, where all computing is done on a central server that is hosted on a high performance system, provides significant benefits to the analysis team. These benefits include a shortened preprocessing time, and potentially higher-quality models.
Design Exploration And Analysis Of Carbon-Infiltrated Carbon Nanotube Vascular Stents, Darrell John Skousen
Design Exploration And Analysis Of Carbon-Infiltrated Carbon Nanotube Vascular Stents, Darrell John Skousen
Theses and Dissertations
The purpose of this research was to design, develop, and test coronary stent designs composed of carbon-infiltrated carbon nanotubes (CI-CNTs). Coronary stents currently have two major complications: restenosis and thrombosis. CI-CNT stents have potential to address both of these issues, and therefore may provide improved clinical outcomes. CI-CNT stent geometry is patterned using high-resolution photolithography that provide advantages in design possibilities.To develop a coronary stent, a standard design process was followed including: background, design specifications, concept generation, development, analysis, and testing. Background research was first completed and general design specifications for coronary stent performance were compiled. Multiple design concepts were …
Real-Time Visualization Of Finite Element Models Using Surrogate Modeling Methods, Ryan C. Heap
Real-Time Visualization Of Finite Element Models Using Surrogate Modeling Methods, Ryan C. Heap
Theses and Dissertations
Finite element analysis (FEA) software is used to obtain linear and non-linear solutions to one, two, and three-dimensional (3-D) geometric problems that will see a particular load and constraint case when put into service. Parametric FEA models are commonly used in iterative design processes in order to obtain an optimum model given a set of loads, constraints, objectives, and design parameters to vary. In some instances it is desirable for a designer to obtain some intuition about how changes in design parameters can affect the FEA solution of interest, before simply sending the model through the optimization loop. This could …
The Biomechanical Implications Of An Intrinsic Decompressive Pre-Load On A Posterior Dynamic Stabilization System, Jeffrey Ellis Harris
The Biomechanical Implications Of An Intrinsic Decompressive Pre-Load On A Posterior Dynamic Stabilization System, Jeffrey Ellis Harris
Theses and Dissertations
The purpose of this research was to investigate the influence of applying an intrinsic decompressive pre-load to a particular dynamic stabilization device on the biomechanical response of the lumbar spine. The FlexSPAR, which supports this ability, was used as a test case. A finite element model of a full lumbar spine was developed and validated against experimental data, and tested in the primary modes of spinal motion. The model was used to compare five lumbar spine test cases: healthy, degenerate, implanted with a pre-loaded device, implanted with a device without a pre-load, and implanted with rigid fixators. Results indicated that …
Biomechanical Implications Of Lumbar Spinal Ligament Transectiona Finite Element Study, Gregory Allen Von Forell
Biomechanical Implications Of Lumbar Spinal Ligament Transectiona Finite Element Study, Gregory Allen Von Forell
Theses and Dissertations
The purpose of this work was to determine the possible effects of isolated spinal ligament transection on the biomechanics of the lumbar spine. A finite element model of a lumbar spine was developed and validated against experimental data. The model was tested in the primary modes of spinal motion in the intact condition, followed by comparative analysis of isolated removal of each spinal ligament. Results showed that stress increased in the remaining ligaments once a ligament was removed, potentially leading to ligament damage. Results also showed changes in bone remodeling "stimulus" which could lead to changes in bone density. Isolated …
Parametric Optimization Design System For A Fluid Domain Assembly, Matthew Jackson Fisher
Parametric Optimization Design System For A Fluid Domain Assembly, Matthew Jackson Fisher
Theses and Dissertations
Automated solid modeling, integrated with computational fluid dynamics (CFD) and optimization of a 3D jet turbine engine has never been accomplished. This is due mainly to the computational power required, and the lack of associative parametric modeling tools and techniques necessary to adjust and optimize the design. As an example, the fluid domain of a simple household fan with three blades may contain 500,000 elements per blade passage. Therefore, a complete turbine engine that includes many stages, with sets of thirty or more blades each, will have hundreds of millions of elements. The fluid domains associated with each blade creates …
Development Of Commercial Applications For Recycled Plastics Using Finite Element Analysis, Nanjunda Narasimhamurthy
Development Of Commercial Applications For Recycled Plastics Using Finite Element Analysis, Nanjunda Narasimhamurthy
Theses and Dissertations
This thesis investigates the suitability of thermo-kinetically recycled plastics for use in commercial product applications using finite element analysis and statistics. Different recycled material blends were tested and evaluated for their use in commercial product applications. There are six different blends of thermo-kinetically recycled plastics used for testing and CATIA is used for finite element analysis. The different types of thermo-kinetically recycled plastics blends are: pop bottles made of PolyethyleneTeraphthalate (PET), milk jugs made of High-Density Polyethylene (HDPE), Vinyl seats made of Poly Vinyl Chloride (PVC) and small amount of Polypropylene (PP) and Urethane, electronic scrap made of engineering resins …