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

Dynamics and Dynamical Systems Commons

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

163 Full-Text Articles 224 Authors 78,453 Downloads 37 Institutions

All Articles in Dynamics and Dynamical Systems

Faceted Search

163 full-text articles. Page 3 of 8.

Investigating The Physical Mechanisms That Impact Electric Fields In The Atmosphere, Greg M. Lucas 2017 University of Colorado at Boulder

Investigating The Physical Mechanisms That Impact Electric Fields In The Atmosphere, Greg M. Lucas

Aerospace Engineering Sciences Graduate Theses & Dissertations

The underlying physics and dynamics of the atmosphere drive electric currents and establish electric fields in a phenomenon known as the global electric circuit (GEC). The GEC has been observed and modeled with limiting assumptions and parameterizations in previous research. This thesis describes the incorporation of a physics-based GEC modeling scheme into a sophisticated climate model to describe the evolution of GEC currents, ground-ionosphere potential, electric fields, and conductivity within the atmosphere. Supporting measurements of atmospheric electric fields over time were used to describe the impact of local meteorological changes and assess the GEC contribution to near-surface electric fields.

The ...


Microsecond State Monitoring Of Nonlinear Time-Varying Dynamic Systems, Jacob Dodson, Bryan Joyce, Applied Research Associates Inc., Simon Laflamme, Janet Wolfson 2017 Air Force Research Laboratory

Microsecond State Monitoring Of Nonlinear Time-Varying Dynamic Systems, Jacob Dodson, Bryan Joyce, Applied Research Associates Inc., Simon Laflamme, Janet Wolfson

Civil, Construction and Environmental Engineering Conference Presentations and Proceedings

Reliable operation of next generation high-speed complex structures (e.g. hypersonic air vehicles, space structures, and weapons) relies on the development of microsecond structural health monitoring (μSHM) systems. High amplitude impacts may damage or alter the structure, and therefore change the underlying system configuration and the dynamic response of these systems. While state-of-the-art structural health monitoring (SHM) systems can measure structures which change on the order of seconds to minutes, there are no real-time methods for detection and characterization of damage in the microsecond timescales.

This paper presents preliminary analysis addressing the need for microsecond detection of state and parameter ...


Experimental Study On Viscoelastic Fluid-Structure Interactions, Anita Anup Dey 2017 University of Massachusetts Amherst

Experimental Study On Viscoelastic Fluid-Structure Interactions, Anita Anup Dey

Masters Theses

It is well known that when a flexible or flexibly-mounted structure is placed perpendicular to the flow of a Newtonian fluid, it can oscillate due to the shedding of separated vortices at high Reynolds numbers. If the same flexible object is placed in non-Newtonian flows, however, the structure's response is still unknown. The main objective of this thesis is to introduce a new field of viscoelastic fluid-structure interactions by showing that the elastic instabilities that occur in the flow of viscoelastic fluids can drive the motion of a flexible structure placed in its path. Unlike Newtonian fluids, the flow ...


Frontal Crash Analysis Of A Conformable Cng Tank Using Finite Element Analysis, Datta Sandesh Manjunath 2017 Michigan Technological University

Frontal Crash Analysis Of A Conformable Cng Tank Using Finite Element Analysis, Datta Sandesh Manjunath

Dissertations, Master's Theses and Master's Reports

The purpose of this study is to computationally model and analyze a Conformable Compressed Natural Gas (CNG) fuel tank for frontal crashes using Finite Element Analysis. Researchers have developed a CNG fuel tank, which is conformable, non-conventional and non-cylindrical. This tank increases cost efficiency, volumetric efficiency and cargo efficiency in CNG vehicle applications. A lightweight pickup truck (2015 Chevrolet Silverado) has been used to integrate the CNG tanks and field-testing has been conducted to demonstrate the application.

The report mainly focuses on the effective finite element modeling of the chassis, brackets and tanks using HYPERMESH and RADIOSS. The frontal crash ...


Compact Facility For Testing Steady And Transient Thermal Performance Of Building Walls, Aimee Byrne, Gerard Byrne, Anthony Robinson 2017 Technological University Dublin

Compact Facility For Testing Steady And Transient Thermal Performance Of Building Walls, Aimee Byrne, Gerard Byrne, Anthony Robinson

Articles

Energy efficiency retrofit of buildings represents a key effort in reducing EU energy demand by 20% by 2020. However, predictions tend to overestimate savings by large percentages. The shortfall in savings can be attributed to incorrect predictive techniques, comfort takeback along with other behavioural and workmanship variables. Common predictive techniques related to heat loss tend to be based on the U-value of the building envelope. This paper presents the design of a more straightforward and compact version of the traditional Hot-Box apparatus (measures U-value) which instead determines the thermal resistance of samples of building envelope. U-value includes the need to ...


Intensity And Resolution Enhancement Of Local Regions For Object Detection And Tracking In Wide Area Surveillance, Evan Krieger, Vijayan K. Asari, Saibabu Arigela, Theus H. Aspiras 2016 University of Dayton

Intensity And Resolution Enhancement Of Local Regions For Object Detection And Tracking In Wide Area Surveillance, Evan Krieger, Vijayan K. Asari, Saibabu Arigela, Theus H. Aspiras

Vijayan K. Asari

Object tracking in wide area motion imagery is a complex problem that consists of object detection and target tracking over time. This challenge can be solved by human analysts who naturally have the ability to keep track of an object in a scene. A computer vision solution for object tracking has the potential to be a much faster and efficient solution. However, a computer vision solution faces certain challenges that do not affect a human analyst. To overcome these challenges, a tracking process is proposed that is inspired by the known advantages of a human analyst. First, the focus of ...


Cement Asphalt Mortar Modelling And Its Influence On High-Speed Train–Bridge System In Presence Of Moderate Earthquakes And Service Loading, Lingkun Chen 2016 Yangzhou University

Cement Asphalt Mortar Modelling And Its Influence On High-Speed Train–Bridge System In Presence Of Moderate Earthquakes And Service Loading, Lingkun Chen

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Nondestructive Testing And Structural Health Monitoring Based On Adams And Svm Techniques, Gang Jiang, Yi Ming Deng, Ji Tai Niu 2016 Southwest University of Science and Technology

Nondestructive Testing And Structural Health Monitoring Based On Adams And Svm Techniques, Gang Jiang, Yi Ming Deng, Ji Tai Niu

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Modelling The Evaporation Of Aluminum In Ti–6al–4v Alloy Melted With Electron Beam And Laser, Xuan Wang, Liang Wang, Liang S. Luo, Yan Q. Su, Xin Z. Li, Rui R. Chen, JIng J. Guo, Heng Z. Fu 2016 Harbin Institute of Technology

Modelling The Evaporation Of Aluminum In Ti–6al–4v Alloy Melted With Electron Beam And Laser, Xuan Wang, Liang Wang, Liang S. Luo, Yan Q. Su, Xin Z. Li, Rui R. Chen, Jing J. Guo, Heng Z. Fu

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Numerical Modeling And Seismic Assessment Of Smart Isolation System For High-Speed Railway Rc Bridge Subjected To Near-Field Ground Motions, Lingkun Chen 2016 Yangzhou University

Numerical Modeling And Seismic Assessment Of Smart Isolation System For High-Speed Railway Rc Bridge Subjected To Near-Field Ground Motions, Lingkun Chen

The 8th International Conference on Physical and Numerical Simulation of Materials Processing

No abstract provided.


Optimization Of Takeoffs On Unbalanced Fields Using Takeoff Performance Tool, Nihad E. Daidzic 2016 AAR Aerospace Consulting, LLC

Optimization Of Takeoffs On Unbalanced Fields Using Takeoff Performance Tool, Nihad E. Daidzic

International Journal of Aviation, Aeronautics, and Aerospace

Unbalanced field length exists when ASDA and TODA are not equal. Airport authority may add less expensive substitutes to runway full-strength pavement in the form of stopways and/or clearways to basic TORA to increase operational takeoff weights. Here developed Takeoff Performance Tool is a physics-based total-energy model used to simulate FAR/CS 25 regulated airplane takeoffs. Any aircraft, runway, and environmental conditions can be simulated, while complying with the applicable regulations and maximizing performance takeoff weights. The mathematical model was translated into Matlab, Fortran 95/2003/2008, Basic, and MS Excel computer codes. All existing FAR/CS 25 takeoff ...


Experimental Building Demonstration Model With Viscous Fluid Dampers, Blake Thomas Reeve, Brianna Jean Kufa, Aden Malek Stepanians, Sophie Carmion Ratkovich 2016 California Polytechnic State University, San Luis Obispo

Experimental Building Demonstration Model With Viscous Fluid Dampers, Blake Thomas Reeve, Brianna Jean Kufa, Aden Malek Stepanians, Sophie Carmion Ratkovich

Architectural Engineering

The Architectural Engineering major places a heavy emphasis on structural dynamics and the role of wind and seismic loading in building analysis and design. Buildings of high importance that are critical to community function, such as hospitals, often utilize supplemental damping devices like supplemental viscous fluid dampers or base isolators to reduce the overall demands on the structural system. The design and analysis of these dampers are typically not taught at the undergraduate level, and is frequently performed by mechanical engineers, in lieu of structural engineers.

To better understand and research building behavior with supplemental damping devices, our multi-disciplinary team ...


Biomimetic Seal Flipper Test Rig, Gordon D. Belyea, Laura Kawashiri, Dylan Rinker, Kurt Beske 2016 California Polytechnic State University, San Luis Obispo

Biomimetic Seal Flipper Test Rig, Gordon D. Belyea, Laura Kawashiri, Dylan Rinker, Kurt Beske

Mechanical Engineering

No abstract provided.


Procesy Cieplne I Aparaty (Lab), Wojciech M. Budzianowski 2016 Wroclaw University of Technology

Procesy Cieplne I Aparaty (Lab), Wojciech M. Budzianowski

Wojciech Budzianowski

-


Inżynieria Chemiczna Lab., Wojciech M. Budzianowski 2016 Wroclaw University of Technology

Inżynieria Chemiczna Lab., Wojciech M. Budzianowski

Wojciech Budzianowski

-


The Pneumatic Leg Extension, David G. Sedano 2016 Central Washington University

The Pneumatic Leg Extension, David G. Sedano

All Undergraduate Projects

In recent years, reaching altitudes that are higher than your normal-height has evolved from pure amusement to an “in-demand” necessity out in the field. Means of achieving greater than normal height range from wooden poles to aluminum stilts. The era of ladders and other extension methods are slowly fading away. There are many designs in the market that focus on different factors to make a stilt. As other designs focus on one or two enhancements, the pneumatic leg extension’s objective is to improve all aspects of the stilt. This radical new design differs greatly from traditional stilt designs. The ...


Case Studies Of Cavity And External Wall Insulation Retrofitted Under The Irish Home Energy Saving Scheme: Technical Analysis And Occupant Perspectives, Aimee Byrne, Gerard Byrne, Garrett O'Donnell, Anthony Robinson 2016 Technological University Dublin

Case Studies Of Cavity And External Wall Insulation Retrofitted Under The Irish Home Energy Saving Scheme: Technical Analysis And Occupant Perspectives, Aimee Byrne, Gerard Byrne, Garrett O'Donnell, Anthony Robinson

Articles

The residential sector represents 27% of primary energy consumption in Ireland. This paper examines the case study of the Irish government’s national grant scheme to encourage energy efficiency retrofit in private housing. That is the Home Energy Saving (HES) Scheme, later rebranded the Better Energy: Homes (BEH) Scheme. The methodology involved monitoring several homes immediately before and after retrofit alongside discussions with occupants. The examination focused on specific measures commonly introduced through the HES/BEH programme − cavity and external wall insulation. It has been found that a significant decrease in heat loss through the walls was measured in all ...


Autonomous Mission Design In Extreme Orbit Environments, David Allen Surovik 2016 University of Colorado at Boulder

Autonomous Mission Design In Extreme Orbit Environments, David Allen Surovik

Aerospace Engineering Sciences Graduate Theses & Dissertations

An algorithm for autonomous online mission design at asteroids, comets, and small moons is developed to meet the novel challenges of their complex non-Keplerian orbit environments, which render traditional methods inapplicable. The core concept of abstract reachability analysis, in which a set of impulsive maneuvering options is mapped onto a space of high-level mission outcomes, is applied to enable goal-oriented decision-making with robustness to uncertainty. These nuanced analyses are efficiently computed by utilizing a heuristic-based adaptive sampling scheme that either maximizes an objective function for autonomous planning or resolves details of interest for preliminary analysis and general study. Illustrative examples ...


Integrated Solar Technologies With Outdoor Pedestrian Bridge Superstructure Decking, Richard K. Racz Mr., Richard Racz 2016 University of Massachusetts Amherst

Integrated Solar Technologies With Outdoor Pedestrian Bridge Superstructure Decking, Richard K. Racz Mr., Richard Racz

Masters Theses

Solar technology has been a major topic in sustainable design for many years. In the last five years, however, the solar technology industry has seen a rapid growth in installations and technological advances in cell design. Combined with a rapidly declining overall system cost, the idea of introducing solar technology into a wider range of applications is becoming a focus for engineers and scientists around the world. So many variables which alter solar energy production, such as the sun and surrounding environment, determine whether a solar design is beneficial. This thesis presents a bridge deck surface integrated with solar cells ...


Full-Field Structural Dynamics By Video Motion Manipulations, Yongchao Yang, Charles Farrara, David Mascarenasa 2016 Los Alamos National Laboratory

Full-Field Structural Dynamics By Video Motion Manipulations, Yongchao Yang, Charles Farrara, David Mascarenasa

Review of Progress in Quantitative Nondestructive Evaluation

Structures with complex geometries, material properties, and boundary conditions, exhibit spatially local, temporally transient, dynamic behaviors. High spatial and temporal resolution vibration measurements and modeling are thus required for high-fidelity characterization, analysis, and prediction of the structure’s dynamic phenomena. For example, high spatial resolution mode shapes are needed for accurate vibration-based damage localization. Also, higher order vibration modes typically contain local structural features that are essential for high-fidelity dynamic modeling of the structure. In addition, while it is possible to build a highly- refined mathematical model (e.g., a finite element model) of the structure, it needs to be ...


Digital Commons powered by bepress