Open Access. Powered by Scholars. Published by Universities.®

Aerospace Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

5,626 Full-Text Articles 7,008 Authors 2,171,447 Downloads 114 Institutions

All Articles in Aerospace Engineering

Faceted Search

5,626 full-text articles. Page 7 of 191.

Hierarchical Optimal Force-Position Control Of A Turning Process, B. Pandurangan, Robert G. Landers, S. N. Balakrishnan 2019 Missouri University of Science and Technology

Hierarchical Optimal Force-Position Control Of A Turning Process, B. Pandurangan, Robert G. Landers, S. N. Balakrishnan

Robert G. Landers

Machining process control technologies are currently not well integrated into machine tool controllers and, thus, servomechanism dynamics are often ignored when designing and implementing process controllers. In this brief, a hierarchical controller is developed that simultaneously regulates the servomechanism motions and cutting forces in a turning operation. The force process and servomechanism system are separated into high and low levels, respectively, in the hierarchy. The high-level goal is to maintain a constant cutting force to maximize productivity while not violating a spindle power constraint. This goal is systematically propagated to the lower level and combined with the low-level goal to ...


Hierarchical Optimal Force-Position-Contour Control Of Machining Processes. Part Ii. Illustrative Example, Yan Tang, Robert G. Landers, S. N. Balakrishnan 2019 Missouri University of Science and Technology

Hierarchical Optimal Force-Position-Contour Control Of Machining Processes. Part Ii. Illustrative Example, Yan Tang, Robert G. Landers, S. N. Balakrishnan

Robert G. Landers

There has been a tremendous amount of research in machine tool servomechanism control, contour control, and machining force control; however, to date these technologies have not been tightly integrated. This paper develops a hierarchical optimal control methodology for the simultaneous regulation of servomechanism positions, contour error, and machining forces. The contour error and machining force process reside in the top level of the hierarchy where the goals are to 1) drive the contour error to zero to maximize quality and 2) maintain a constant cutting force to maximize productivity. These goals are systematically propagated to the bottom level, via aggregation ...


Hierarchical Optimal Control Of A Turning Process - Linearization Approach, Anand Dasgupta, B. Pandurangan, Robert G. Landers, S. N. Balakrishnan 2019 Missouri University of Science and Technology

Hierarchical Optimal Control Of A Turning Process - Linearization Approach, Anand Dasgupta, B. Pandurangan, Robert G. Landers, S. N. Balakrishnan

Robert G. Landers

Machining process control technologies are currently not well integrated into machine tool controllers and, thus, servomechanism dynamics are often ignored when designing and implementing process controllers. In this paper, a hierarchical controller is developed that simultaneously regulates the servomechanism positions and cutting forces in a lathing operation. The force process and servomechanism system are separated into high and low levels, respectively, in the hierarchy. The high level goal is to maintain a constant cutting force to maximize productivity while not violating a spindle power constraint. This goal is systematically propagated to the lower level and combined with the low level ...


Automatic Feedback Control Of Mechanical Gas Face Seals Via Clearance Control, Sachin S. Yelma, Robert G. Landers, Brad A. Miller 2019 Missouri University of Science and Technology

Automatic Feedback Control Of Mechanical Gas Face Seals Via Clearance Control, Sachin S. Yelma, Robert G. Landers, Brad A. Miller

Robert G. Landers

An approach based on proper orthogonal decomposition and Galerkin projection is presented for developing low-order nonlinear models of the gas film pressure within mechanical gas face seals. A technique is developed for determining an optimal set of global basis functions for the pressure field using data measured experimentally or obtained numerically from simulations of the seal motion. The reduced-order gas film models are shown to be computationally efficient compared to full-order models developed using the conventional semidiscretization methods. An example of a coned mechanical gas face seal in a flexibly mounted stator configuration is presented. Axial and tilt modes of ...


Automation Of Hybrid Manufacturing System Through Tight Integration Of Software And Sensor Feedback, Robert G. Landers, Frank W. Liou, Jacquelyn K. Stroble 2019 Missouri University of Science and Technology

Automation Of Hybrid Manufacturing System Through Tight Integration Of Software And Sensor Feedback, Robert G. Landers, Frank W. Liou, Jacquelyn K. Stroble

Robert G. Landers

This paper presents a framework for the automation of the Laser Aided Manufacturing Process (LAMP) lab at the University of Missouri-Rolla. The groundwork for the proposed system involves the integration of the LabVIEW software package and a PXI-8195 real time controller with several sensors and actuators. The incorporation of all key control parameters into one virtual instrument will help achieve the goal of an automated hybrid system. To achieve this goal, a five-phase plan, which will be further discussed in the paper, has been developed. The first phase of this plan, which includes the deposition of a thin walled structure ...


Adaptive Control Of Freeze-Form Extrusion Fabrication Processes, Xiyue Zhao, Robert G. Landers, Ming-Chuan Leu 2019 Missouri University of Science and Technology

Adaptive Control Of Freeze-Form Extrusion Fabrication Processes, Xiyue Zhao, Robert G. Landers, Ming-Chuan Leu

Robert G. Landers

Freeze-form Extrusion Fabrication (FEF) is an additive manufacturing process that extrudes high solids loading aqueous ceramic pastes in a layer-by-layer fashion below the paste freezing temperature for component fabrication. Due to effects such as the air bubble release, agglomerate breakdown, change in paste properties during extrusion as a result of liquid phase migration, etc., the extrusion force is difficult to control. In this paper, an adaptive controller is proposed to regulate the extrusion force. Recursive Least Squares is used to estimate extrusion force model parameters during fabrication and a low-order control scheme capable of tracking general reference trajectories is designed ...


Forensic Investigation Of Failed Mast Arms Of Traffic Signal Supported Structures, Genda Chen, Michael G. Barker, D. Scott MacKenzie, Christopher W. Ramsay, Joe Alderson, Lokeswarappa R. Dharani, Jiaqing Yu 2019 Missouri University of Science and Technology

Forensic Investigation Of Failed Mast Arms Of Traffic Signal Supported Structures, Genda Chen, Michael G. Barker, D. Scott Mackenzie, Christopher W. Ramsay, Joe Alderson, Lokeswarappa R. Dharani, Jiaqing Yu

Lokeswarappa Dharani

In Missouri, 11 traffic signal mast arms fractured at the arm-post weld connection in 7 years. To reduce this fatigue failure, the Missouri Department of Transportation developed a fatigue-resistant weld profile that increases the weld leg and reduces the slope of the weld at the toe. This study investigated causes of the failed arms, compared performance of new and old weld profiles, and suggested retrofitting measures for further investigation. The scope included a metallurgical investigation of one failed field mast arm, laboratory fatigue testing of five prototype mast arms (two new and three old profiles), and laboratory failure analysis of ...


Fatigue Assessment Of Traffic Signal Mast Arms Based On Field Test Data Under Natural Wind Gusts, Genda Chen, Jingning Wu, Jiaqing Yu, Lokeswarappa R. Dharani, Michael G. Barker 2019 Missouri University of Science and Technology

Fatigue Assessment Of Traffic Signal Mast Arms Based On Field Test Data Under Natural Wind Gusts, Genda Chen, Jingning Wu, Jiaqing Yu, Lokeswarappa R. Dharani, Michael G. Barker

Lokeswarappa Dharani

In recent years, several states including Missouri, Wyoming, California, and Texas experienced fracture failures of traffic signal mast arms. Almost all the failures are associated with the propagation of defects or cracks. It is therefore imperative to evaluate existing mast arms using a simple yet accurate procedure. A statistical methodology is proposed to predict the fatigue life of signal mast arm structures on the basis of field-measured strain data. The annual occurrence of various stress levels is determined using the historical wind speed data in the vicinity of a mast arm structure and the strain readings of the structure under ...


Effect Of Polymer-Surface Mobility On Adhesion In Poly(Methyl Methacrylate)-Tape System, Bhavesh C. Gandhi, Frank D. Blum, Lokeswarappa R. Dharani 2019 Missouri University of Science and Technology

Effect Of Polymer-Surface Mobility On Adhesion In Poly(Methyl Methacrylate)-Tape System, Bhavesh C. Gandhi, Frank D. Blum, Lokeswarappa R. Dharani

Lokeswarappa Dharani

The interaction between two polymer layers, especially adhesion between them, plays an important role in polymer processing and other applications. Detailed knowledge of the molecular structure and dynamics of polymer interfaces, and how they relate to macroscopic mechanical properties, should help designers construct more functional systems. Unfortunately, there have been few studies where both molecular and macroscopic studies have been performed on similar systems. In previous studies from our group, we have probed the dynamics of poly(methyl acrylate) (PMA) and thermal behavior of poly(methyl methacrylate) (PMMA) on silica. These studies helped us paint a picture for strongly bound ...


Effect Of Interfacial Mobility On Flexural Strength And Fracture Toughness Of Glass/Epoxy Laminates, T. W. H. Wang, Frank D. Blum, Lokeswarappa R. Dharani 2019 Missouri University of Science and Technology

Effect Of Interfacial Mobility On Flexural Strength And Fracture Toughness Of Glass/Epoxy Laminates, T. W. H. Wang, Frank D. Blum, Lokeswarappa R. Dharani

Lokeswarappa Dharani

Mechanical testing and surface fractography were used to characterize the fracture of E-glass fiber reinforced epoxy composites as a function of the silane coupling agent used. gamma-Aminopropyltriethoxysilane (APS) and delta-aminobutyltriethoxysilane (ABS) were used because these have been shown to have different interfacial mobilities at multilayer coverage. The values of the properties studied generally increased from untreated c, as determined from a Mode I translaminar fracture toughness tests, for the untreated composites (10.5 ± 0.4 kJ/m2) was lower than that for the ABS-treated composites (14.3 ± 2.1 kJ/m2) which was lower than that for the APS-treated composites ...


Analysis Of Damage In Laminated Automotive Glazing Subjected To Simulated Head Impact, Shuangmei Zhao, Li Chai, S. D. Barbat, Lokeswarappa R. Dharani 2019 Missouri University of Science and Technology

Analysis Of Damage In Laminated Automotive Glazing Subjected To Simulated Head Impact, Shuangmei Zhao, Li Chai, S. D. Barbat, Lokeswarappa R. Dharani

Lokeswarappa Dharani

During vehicle accidents, occupant's head impacting on windshield or side window is commonly observed. Any attempt to design glazing that minimizes injury to and death of occupants during a vehicle accident requires a thorough understanding of the mechanical behavior of automotive glazing subjected to head impact loads. A continuum damage mechanics (CDM) based constitutive model is developed and implemented into an axisymmetric finite element model to study the failure and impact resistance of laminated automotive glazing subjected to simulated head impact. An anisotropic elastic damage tensor with a linear damage evolution law is chosen to model the failure of ...


Educating The Space Scientists At Embry-Riddle Through Design, Build And Fly Rocketry Experience, Pedro Llanos, Robert E. Haley, Sathya Gangadharan 2019 Embry-Riddle Aeronautical University - Daytona Beach

Educating The Space Scientists At Embry-Riddle Through Design, Build And Fly Rocketry Experience, Pedro Llanos, Robert E. Haley, Sathya Gangadharan

Pedro J. Llanos (www.AstronauticsLlanos.com)

Practical experience for students in rockets and payloads is very valuable in the space industry, and it is something that would give them an advantage over other applicants. Students in Embry-Riddle Aeronautical University’s Payload and Integration class were given the opportunity to build a level 1 rocket and gain experience developing, testing, and integrating payloads into a rocket. The students were given the tasks to come up with an idea for a payload, design the payload to fit within the rocket for flight, and assemble and launch the rocket with the payload in the payload bay. The tasks required ...


Project Atlas: A Mobile Universal Rocket Engine Test Stand, Collin Mickels, Conrad H. Wright, Noah Soderquist, Alona Prokofieva, Sattar Panahandehgar, Naveen Sri Uddanti, Alcuin Rajan 2019 Embry-Riddle Aeronautical University

Project Atlas: A Mobile Universal Rocket Engine Test Stand, Collin Mickels, Conrad H. Wright, Noah Soderquist, Alona Prokofieva, Sattar Panahandehgar, Naveen Sri Uddanti, Alcuin Rajan

Student Works

Project Atlas is a mobile, trailer-mounted, rocket engine test stand developed by Experimental Rocket Propulsion Lab (ERPL) at Embry-Riddle Aeronautical University’s Daytona Beach, Florida campus. The integrated test stand and automated data-acquisition and control system supports ERPL’s multitude of engine research projects, including bipropellant liquid and hybrid rocket engines. The need for an integrated universal mobile test stand stems from the inability to conduct frequent test fires on campus due to Class-3 airspace and liability issues. The test stand is designed as a horizontal thrust structure utilizing a dual flame duct to redirect and cancel reaction forces acting ...


Mechanical And Aerospace Engineering, 2018-2019, College of Engineering and Applied Sciences 2019 Western Michigan University

Mechanical And Aerospace Engineering, 2018-2019, College Of Engineering And Applied Sciences

Mechanical and Aerospace Engineering News

  • Letter from the Chair
  • Introducing Dr. Zachary D. Asher
  • Department of Mechanical and Aerospace Engineering develops an engineering flight simulator
  • Gear Sliding Loss Prediction
  • Ph.D. student receives the prestigious NASA Earth and Space Science Fellowship
  • NSF grant allows important materials research
  • Student receives scholarship from gear industry
  • Development of low cost/high volume micro/nano sensors and actuators
  • Liou receives $204,000 NSF grant for neurological research
  • Alexander Porter inducted into the Alumni Excellence Academy


Insar Simulations For Swot And Dual Frequency Processing For Topographic Measurements, Gerard Masalias Huguet 2019 University of Massachusetts Amherst

Insar Simulations For Swot And Dual Frequency Processing For Topographic Measurements, Gerard Masalias Huguet

Masters Theses

In Earth remote sensing precise characterization of the backscatter coefficient is important to extract valuable information about the observed target. A system that eliminates platform motion during near-nadir airborne observations is presented in this thesis, showing an improvement on the accuracy of measurements for a Ka- band scatterometer previously developed at Microwave Remote Sensing Laboratory (MIRSL). These very same results are used to simulate the reflectivity of such targets as seen from a spaceborne radar and estimate height errors based on mission-specific geometry. Finally, data collected from a dual-frequency airborne interferometer com- prised by the Ka-band system and an S-band ...


An End-To-End Platform For Autonomous Dynamic Soaring In Wind Shear, Corey Montella 2019 Lehigh University

An End-To-End Platform For Autonomous Dynamic Soaring In Wind Shear, Corey Montella

Theses and Dissertations

Despite advancements in our understanding of flight in modern times, birds remain unmatched when it comes to maneuverability and energy efficiency in flight; in particular seabirds like the albatross are known to travel vast distances without stopping for food by performing an aerobatic maneuver called dynamic soaring. When the maneuver is executed in the presence of a wind field that varies in strength of direction, the albatross extracts kinetic energy from the field. In this dissertation, we present an end-to-end system designed to exploit wind as the albatross does. The system we designed consists of a gliding platform outfitted with ...


High-Pressure Phase Transformations Under Severe Plastic Deformation By Torsion In Rotational Anvils, Valery I. Levitas 2019 Iowa State University and Ames Laboratory

High-Pressure Phase Transformations Under Severe Plastic Deformation By Torsion In Rotational Anvils, Valery I. Levitas

Aerospace Engineering Publications

Numerous experiments have documented that combination of severe plastic deformation and high mean pressure during high-pressure torsion in rotational metallic, ceramic, or diamond anvils produces various important mechanochemical effects. We will focus here on four of these: plastic deformation (a) significantly reduces pressure for initiation and completion of phase transformations (PTs), (b) leads to discovery of hidden metastable phases and compounds, (c) reduces PT pressure hysteresis, and (d) substitutes a reversible PT with irreversible PT. The goal of this review is to summarize our current understanding of the underlying phenomena based on multiscale atomistic and continuum theories and computational modeling ...


Scaling Analysis And Experimental Investigation Of A Rotating Detonation Engine, David Thomas Billups 2019 West Virginia University

Scaling Analysis And Experimental Investigation Of A Rotating Detonation Engine, David Thomas Billups

Graduate Theses, Dissertations, and Problem Reports

Pressure gain combustion (PGC) technologies, specifically rotating detonation engines (RDEs), are poised to provide the next big leap in gas turbine engine advancement, significantly increasing the thermal. RDEs make use of thermodynamic advantages of isochoric as opposed to isobaric combustion. Theorized to increase thermal efficiency by up to 7% [1], the RDE would have significant impact on reducing anthropogenic carbon emissions. In addition to efficiency gains, the RDE also provides mechanical simplicity and reduced size advantages compared to it’s traditional counterparts and PGC competition.

The United States (U.S.) Department of Energy (DOE) National Energy Technology Laboratory (NETL) maintains ...


Generator Design: A Study Of Optimized Airflow, Rachel Wattleworth 2019 The University of Akron

Generator Design: A Study Of Optimized Airflow, Rachel Wattleworth

Williams Honors College, Honors Research Projects

The core goal of this project was to prototype, test, and evaluate a new type of fan for the Safran Electrical & Power air-cooled generators. The idea of a new fan being made for these two generators arose when they were not adhering to design requirements. A base mixed-flow fan was created to test on multiple generators. Upon creating a prototype, it will be tested to prove if it can increase the air flow, decrease temperatures, and increase power and life of the machines. They all proved to be successful and achieve the main objectives for this project. Data such as ...


Space Dynamics Laboratory Payload Challenge: Autonomous Water Sampling Uav, Thomas Wheeler, Zachary Williams, Joseph Stack 2019 The University of Akron

Space Dynamics Laboratory Payload Challenge: Autonomous Water Sampling Uav, Thomas Wheeler, Zachary Williams, Joseph Stack

Williams Honors College, Honors Research Projects

The following report has been completed over the course of the Fall 2018 and Spring 2019 semesters at The University of Akron by Joseph P. Stack (Aerospace Systems Engineering), Thomas J. Wheeler (Mechanical Engineering) and Zachary M. Williams (Mechanical Engineering). The purpose of this project was to create a payload system for the Akronauts Rocket Design Team to use at the Intercollegiate Rocket Engineering Competition (IREC) Spaceport America Cup. The Competition as a challenge that is sponsored by Space Dynamics Laboratory specifically regarding payload systems. The challenge in very open-ended and allows student to identify their own scientific experiment and ...


Digital Commons powered by bepress