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- <p>Mechanical movements -- Research<br />Dynamics (1)
- Adaptive Path Compensation (1)
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- Air Breathing Fuel Cells (1)
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- Ceramic materials -- Extrusion<br />Solid freeform fabrication<br />Manufacturing processes (1)
- Compliant Mechanisms (1)
- Component Functionality (1)
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- Manufacturing processes -- Automation<br />Rapid prototyping<br />Solid freeform fabrication<br />Ceramics -- Extrusion (1)
- Manufacturing processes -- Research<br />Robots, Industrial -- Research<br />Intelligent control systems<br />Pulsed laser deposition (1)
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Articles 1 - 9 of 9
Full-Text Articles in Engineering
Methodology For Analysis Of Stress, Creep, And Fatigue Behavior Of Compliant Mechanisms, Joshua Allen Crews
Methodology For Analysis Of Stress, Creep, And Fatigue Behavior Of Compliant Mechanisms, Joshua Allen Crews
Doctoral Dissertations
"A methodology is developed for analyzing stress within homogeneous and metallic-reinforced, fixed-free compliant segments and small-length flexural pivots. Boundary conditions related to the inclusion of metallic reinforcing components within a polymer compliant segment are investigated. The analysis method outlined herein relies on key outputs from the pseudo-rigid-body models (PRBMs). A method is presented for the redesign of compliant mechanisms to include metallic reinforcement to reduce stress while maintaining force-deflection behavior. Examples are provided in which a compliant segment is redesigned to include metallic reinforcement by using the stress equations developed from the PRBM. The effect of bonding between the polymer …
Repetitive Process Control Of Additive Manufacturing With Application To Laser Metal Deposition, Patrick M. Sammons
Repetitive Process Control Of Additive Manufacturing With Application To Laser Metal Deposition, Patrick M. Sammons
Doctoral Dissertations
"Additive Manufacturing (AM) is a set of manufacturing processes which has promise in the production of complex, functional structures that cannot be fabricated with conventional manufacturing and the repair of high-value parts. However, a significant challenge to the adoption of additive manufacturing processes to these applications is proper process control. In order to enable closed-loop process control compact models suitable for control design and for describing the layer-by-layer material addition process are needed. This dissertation proposes a two-dimensional modeling and control framework, with an application to a specific metal-based AM process, whereby the deposition of the current layer is affected …
Research On Hybrid Manufacturing Using Industrial Robot, Zhiyuan Wang
Research On Hybrid Manufacturing Using Industrial Robot, Zhiyuan Wang
Doctoral Dissertations
"The applications of using industrial robots in hybrid manufacturing overcome many restrictions of the conventional manufacturing methods, such as small part building size, long building period, and limited material choices. However, some problems such as the uneven distribution of motion accuracy within robot working volume, the acceleration impact of robot under heavy external loads, few methods and facilities for increasing the efficiency of hybrid manufacturing process are still challenging. This dissertation aims to improve the applications of using industrial robot in hybrid manufacturing by addressing following three categories research issues. The first research issue proposed a novel concept view on …
Efficient Time-Dependent System Reliability Analysis, Zhifu Zhu
Efficient Time-Dependent System Reliability Analysis, Zhifu Zhu
Doctoral Dissertations
"Engineering systems are usually subjected to time-variant loads and operate under time-dependent uncertainty; system performances are therefore time-dependent. Accurate and efficient estimate of system reliability is crucial for decision makings on system design, lifetime cost estimate, maintenance strategy, etc. Although significant progresses have been made in time-independent reliability analysis for components and systems, time-dependent system reliability methodologies are still limited. This dissertation is motivated by the need of accurate and effective reliability prediction for engineering systems under time-dependent uncertainty. Based on the classic First and Second Order Reliability Method (FORM and SORM), a system reliability method is developed for multidisciplinary …
Hierarchical Control Of Complex Manufacturing Processes, Hesam Zomorodi Moghadam
Hierarchical Control Of Complex Manufacturing Processes, Hesam Zomorodi Moghadam
Doctoral Dissertations
"The need for changing the control objective during the process has been reported in many systems in manufacturing, robotics, etc. However, not many works have been devoted to systematically investigating the proper strategies for these types of problems. In this dissertation, two approaches to such problems have been suggested for fast varying systems. The first approach, addresses problems where some of the objectives are statically related to the states of the systems. Hierarchical Optimal Control was proposed to simplify the nonlinearity caused by adding the statically related objectives into control problem. The proposed method was implemented for contour-position control of …
Modeling And Control Of Fuel Cell-Battery Hybrid Energy Sources, Nima Lotfi
Modeling And Control Of Fuel Cell-Battery Hybrid Energy Sources, Nima Lotfi
Doctoral Dissertations
"Environmental, political, and availability concerns regarding fossil fuels in recent decades have garnered substantial research and development in the area of alternative energy systems. Among various alternative energy systems, fuel cells and batteries have attracted significant attention both in academia and industry considering their superior performances and numerous advantages. In this dissertation, the modeling and control of these two electrochemical sources as the main constituents of fuel cell-battery hybrid energy sources are studied with ultimate goals of improving their performance, reducing their development and operational costs and consequently, easing their widespread commercialization. More specifically, Paper I provides a comprehensive background …
Modeling And Evaluation Of Moisture Diffusion In Polymer Composite Materials, Zhen Huo
Modeling And Evaluation Of Moisture Diffusion In Polymer Composite Materials, Zhen Huo
Doctoral Dissertations
"Fiber-reinforced polymer composites have extensive applications due to their high specific strength, improved product performance, low maintenance and design flexibility. However, moisture absorbed by polymer composites during the service life plays a detrimental role in both the integrity and durability of composite structure. It is essential to understand the moisture diffusion behavior and induced damage in polymer matrix composites under varying hygrothermal conditions. In Part I, the moisture diffusion characteristics in hybrid composites using moisture concentration-dependent diffusion method have been investigated. Also, a multi-stage diffusion model was proposed to explain the deviation of moisture diffusion behavior for sandwich composites from …
Novel Design And Manufacturing Strategies For Portable Air-Breathing Proton Exchange Membrane Fuel Cells, Sriram Praneeth Isanaka
Novel Design And Manufacturing Strategies For Portable Air-Breathing Proton Exchange Membrane Fuel Cells, Sriram Praneeth Isanaka
Doctoral Dissertations
"The purpose of this dissertation is to study the importance of design novelty and advanced manufacturing and assembly practices towards portable air-breathing proton exchange membrane fuel cells. Traditional proton exchange membrane fuel cell designs have always been based on prismatic shapes and expensive materials like graphite and steel. The novel design strategies theorized as part of this research though have led to the creation of working prototypes with unconventional form factors, materials and manufacturing methods. The benefits include improved reactant flow characteristics, superior power densities, reduced cost, and simplified manufacturing and assembly complexity as compared to conventional proton exchange membrane …
Modeling, Analysis, And Simulation For Aqueous-Based Ceramic Pastes In Freeze-Form Extrusion Fabrication Process, Mingyang Li
Modeling, Analysis, And Simulation For Aqueous-Based Ceramic Pastes In Freeze-Form Extrusion Fabrication Process, Mingyang Li
Doctoral Dissertations
"During the freeze-form extrusion fabrication process, both the extrusion and freezing processes are complex due to the aqueous-based ceramic pastes' non-Newtonian behavior, large latent heat of the water contained in the paste, and the small temperature difference between the ambient and the paste. In this study, the steady-state relationship between plunger velocity and extrusion force is developed based on a modified Herschel-Bulkley viscosity model and the Navier-Stokes equations, and the dynamic response of the extrusion force is described by a first-order nonlinear equation when plunger velocity is taken as an input. It is shown that the extrusion response time depends …