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Dynamics and Dynamical Systems

2020

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Articles 1 - 14 of 14

Full-Text Articles in Engineering Science and Materials

Dual-Adaptive Camouflage For The Hyperstealth Corperation, Keith J. Carlock Mr. Dec 2020

Dual-Adaptive Camouflage For The Hyperstealth Corperation, Keith J. Carlock Mr.

The STEAM Journal

Dual-Adaptive Camouflage, though still a concept that I've had for 28 years, seems to me, more promising that the bulk and brain power and needed energy supply of a computer-driven network of optical electronic harnesses that would be the basis for any suit that proclaims to render its wearer invisible.


Numerical Simulation Of Nonlinear Vibrations Of Discrete Mass With Harmonic Force Perturbation, M. Yusupov, B. A. Akhmedov, Olga Karpova Dec 2020

Numerical Simulation Of Nonlinear Vibrations Of Discrete Mass With Harmonic Force Perturbation, M. Yusupov, B. A. Akhmedov, Olga Karpova

Acta of Turin Polytechnic University in Tashkent

The problem of vibration of a single-mass system under the force excitation of vibration associated with a fixed base by a weightless nonlinear viscoelastic spring is considered. To take into account the rheological properties of the spring material, the Boltzmann-Volterra principle was used. Mathematical models of the problem under consideration are obtained, which are described by integro-differential equations. A solution method based on the use of quadrature formulas has been developed and a computer program has been compiled on its basis, the results obtained are presented in the form of graphs. The influence of nonlinear and rheological properties of a …


Experimental Study Of Viscoelastic Fluid-Structure Interactions, Anita Anup Dey Dec 2020

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

Doctoral Dissertations

It is well known that when a flexible or flexibly-mounted structure is placed perpendicular to a Newtonian fluid flow, it can oscillate due to the shedding of vortices at high Reynolds numbers. Unlike Newtonian fluids, viscoelastic fluid flow can become unstable even at infinitesimal Reynolds numbers due to a purely elastic flow instability occurring at large Weissenberg numbers. This thesis focuses on exploring the mechanisms of viscoelastic fluid-structure interactions (VFSI) through experimental investigations on several different combinations of flexible and flexibly-mounted circular cylinders, micro and macro-scale cantilevered beams and viscoelastic fluids such as wormlike micelle solutions and polymer solutions. VFSI …


Joint Wind And Ice Effects On Transmission Lines In Mountainous Terrain, Daniel Davalos Arriaga Nov 2020

Joint Wind And Ice Effects On Transmission Lines In Mountainous Terrain, Daniel Davalos Arriaga

Electronic Thesis and Dissertation Repository

Atmospheric icing on mountainous terrain can produce catastrophic damages to transmission lines when incoming particles impinge and accrete on the cable surface of the system. The first challenge in wind-ice loading is determining joint statistics of wind and ice accretion on transmission lines. This study analyzes the weather characteristics for a specific site of study using 15 years of historical data to use as inputs for ice accretion modeling. The joint wind and ice hazard is characterized by simulating 500 years of icing events from the fitted probability distributions of ice accretion and wind on ice velocities. The second challenge …


Adsorption And Reconfiguration Of Amphiphiles At Silica-Water Interfaces: Role Of Electrostatic Interactions, Van Der Waals Forces And Hydrogen Bonds, Yao Wu Nov 2020

Adsorption And Reconfiguration Of Amphiphiles At Silica-Water Interfaces: Role Of Electrostatic Interactions, Van Der Waals Forces And Hydrogen Bonds, Yao Wu

LSU Doctoral Dissertations

The ability to explore and predict metastable structures of hybrid self-assemblies is of central importance for the next generation of advanced materials with novel properties. As compared to their thermodynamically stable forms, the kinetically stabilized materials show improved functionality potentially over their stable counterparts. The self-assembly processes usually originate from weak intermolecular interactions, involving a dynamic competition between attractive and repulsive interactions. These weak forces, including van der Waals (vdW), electrostatic interaction and the hydrogen bonding (H-bonding), can be tuned by external stimuli, e.g., confinement, temperature and ionization, and consequently driving hybrid materials into different configurations. It is challenging to …


Study Of Dynamics Of The Twisting Process In Pneumomechanical Spinning In The Presence Of Double False Spinning, Mirzohid Sayidmurodov Oct 2020

Study Of Dynamics Of The Twisting Process In Pneumomechanical Spinning In The Presence Of Double False Spinning, Mirzohid Sayidmurodov

Acta of Turin Polytechnic University in Tashkent

В данной работе представлены результаты исследования динамики процесса кручения пряжи пневмомеханического прядения (пневмомеханического прядения) при наличии двойного ложного кручения, построены динамические математические модели процесса кручения пряжи пневмомеханического прядения. при наличии двойного ложного скручивания в режимах неустановившегося пуска и остановке формовочно-скручивающего устройства.


The Use And Explanation Of The Phase Angle In Forced Vibration Testing, Nicholas R. Slavin, Ryan D. Thornton Jul 2020

The Use And Explanation Of The Phase Angle In Forced Vibration Testing, Nicholas R. Slavin, Ryan D. Thornton

Architectural Engineering

Forced vibration testing is a tool used to characterize a structure’s dynamic properties. When subjecting a structure to a forced harmonic load, the results help define the structure’s fundamental frequencies and dominant mode shapes. However, when conducting testing, it is difficult to determine the contributions of each mode to the response at a given location in the structure. The recorded response from a forced vibration test is a combination of unknown modal constituents. Excitation may not result in the pure, single mode response that the experimenter desires, but may instead result in a combination of modal responses that obscure the …


Mechani-Kits Senior Design Project, Jake Utley, Sophie Carson, Vincent Seguin Jun 2020

Mechani-Kits Senior Design Project, Jake Utley, Sophie Carson, Vincent Seguin

Mechanical Engineering

Studies suggest that when designed and executed well, hands-on activities can enhance student understanding of key mechanics concepts. Current products are expensive and typically not designed to meet a variety of learning objectives. Through the Mechanics of Inclusion and Inclusivity in Mechanics grant, the Cal Poly Physics and Engineering Departments are seeking to incorporate new hands-on activities into their courses. Our team has designed three inexpensive ”MechaniKits” to be used in physics, statics and dynamics courses [1]. This Final Design Review outlines our findings, objectives, and final designs for this project. It also explains our manufacturing and design verification plans. …


Stationary Exercise Classification Using Imus And Deep Learning, Andrew M. Heroy, Zackary Gill, Samantha Sprague, David Stroud, John Santerre Apr 2020

Stationary Exercise Classification Using Imus And Deep Learning, Andrew M. Heroy, Zackary Gill, Samantha Sprague, David Stroud, John Santerre

SMU Data Science Review

In the current market, successful fitness tracking devices utilize heart rate and GPS to determine performance. These devices are useful, but don't extensively classify stationary exercise. This paper proposes a modern approach for tuning and investigating optimal neural network types on stationary exercises using Inertial Measurement Units (IMUs). Using three IMUs located on the ankle, waist, and wrist, data is collected to map the body as it moves during the stationary physical activity. A novel five-stage deep learning tuning system was written and deployed to classify user movement as one of three classes: air squats, jumping jacks, and kettlebell swings. …


Dynamic And Control Of Air-Bearing Spacecraft Simulator, Jacob Joseph Korczyk Apr 2020

Dynamic And Control Of Air-Bearing Spacecraft Simulator, Jacob Joseph Korczyk

Doctoral Dissertations and Master's Theses

An air bearing is being designed as a spacecraft rotational motion simulator, featuring the Sawyer Robot and its control box. The objective is to maneuver the robot as desired, performing operations specific to on-orbit servicing operations while maintaining stability of the system. Before the control can be designed, the dynamics of the platform and the robot must be modeled. The dynamics of the robot can be derived utilizing a Newton-Euler recursive approach. By beginning with a simple pendulum, then adding links (degrees of freedom) to more closely resemble the Sawyer arm, the equations of motion for the robot can be …


Dual-Axis Solar Tracker, Bryan Kennedy Jan 2020

Dual-Axis Solar Tracker, Bryan Kennedy

All Undergraduate Projects

Renewable energies, and fuels that are not fossil fuel-based, are one of the prolific topics of debate in modern society. With climate change now becoming a primary focus for scientists and innovators of today, one of the areas for the largest amount of potential and growth is that of the capturing and utilization of Solar Energy. This method involves using a mechanical system to track the progression of the sun as it traverses the sky throughout the day. A dual-axis solar tracker such as the one designed and built for this project, can follow the sun both azimuthally and in …


Atv Dynamics And Pediatric Rider Safety, James T. Auxier Ii Jan 2020

Atv Dynamics And Pediatric Rider Safety, James T. Auxier Ii

Theses and Dissertations--Biomedical Engineering

It has been observed through numerous academic and governmental agency studies that pediatric all-terrain vehicle ridership carries significant risk of injury and death. While no doubt valuable to safety, the post-hoc approach employed in these studies does little to explain the why and how behind the risk factors. Furthermore, there has been no prolonged, widespread, organized, and concerted effort to reconstruct and catalog the details and causes of the large (20,000+) number of ATV-related injuries that occur each year as has been done for road-based motor vehicle accidents. This dissertation takes the opposite approach from a meta-analysis and instead examines …


Generation Of Warm Dense Plasma On Solar Panel Infrastructure In Exo-Atmospheric Conditions, Harrison C. Wenzel Jan 2020

Generation Of Warm Dense Plasma On Solar Panel Infrastructure In Exo-Atmospheric Conditions, Harrison C. Wenzel

Theses and Dissertations

The use of a weaponized thermo-nuclear device in exo-atmospheric conditions would be of great impact on the material integrity of orbiting satellite infrastructure. Particular damage would occur to the multi-layered, solar cell components of such satellites. The rapid absorption of X-ray radiation originating from a nuclear blast into these layers occurs over a picosecond time scale and leads to the generation of Warm Dense Plasma (WDP). While incredibly difficult and costly to replicate in a laboratory setting, a collection of computational techniques and software libraries may be utilized to simulate the intricate atomic and subatomic physics characteristics of such an …


Capillary Forces And Wetting Dynamics By Diffuse-Interface Modeling, Fanny Thomas Jan 2020

Capillary Forces And Wetting Dynamics By Diffuse-Interface Modeling, Fanny Thomas

Dissertations and Theses

Wetting phenomena underlie many natural and industrial processes, from the proper functioning of the lungs to the thin coating of surfaces. The three-phase interactions involved at microscopic scales play a critical role. Adding solid particles to an emulsion, for example, can drastically change the flow behavior due to capillary bridging between the particles. The study of these three-phase systems is especially relevant to the petroleum industry, where gas hydrates forming large clusters in subsea pipelines during crude oil transportation is a major concern. The dynamics of such systems is also of great interest from a fundamental perspective. Indeed describing non-equilibrium …