Browsing by Department "Aerospace Engineering"
Now showing items 1-20 of 421
-
3D Maneuvers For Asymmetric Under-Actuated Rigid Body
(2013-08-01)Most spacecraft are designed to be maneuvered to achieve pointing goals. This is generally accomplished by designing a three-axis control system. This work explores new maneuver strategies when only two control inputs are ... -
3D Multi-Field Multi-Scale Features From Range Data In Spacecraft Proximity Operations
(2012-07-16)A fundamental problem in spacecraft proximity operations is the determination of the 6 degree of freedom relative navigation solution between the observer reference frame and a reference frame tied to a proximal body. For ... -
A Biologically Based Spatio-Temporal Framework for the Matching and Encoding of Data
(2015-07-08)This thesis presents a neuron model and framework for the architecture and interaction of neurons in order to accomplish two tasks, 1) data matching, and 2) the storage and retrieval of information. The tasks are approached ... -
A Comparative Study of Estimation Models for Satellite Relative Motion
(2013-01-31)The problem of relative spacecraft motion estimation is considered with application to various reference and relative orbits. Mean circular and elliptic orbits are analyzed, with relative orbits ranging in size from 1 km ... -
A Finite Element-Multibody Dynamics Co-simulation Methodology Applied to FAST
(2013-05-02)A co-simulation methodology is explored whereby a finite element code and a multi-body dynamics code featuring flexible cantilevered beams can be coupled and interactively executed. The floating frame of reference formulation ... -
A Gradient-based Constitutive Model to Predict Size Effects in the Response of Shape Memory Alloys
(2015-06-05)Shape memory alloys (SMAs) show size effect in their response because the behavior of small-scale SMA structures deviates from that of the bulk material. Ni-Fe-Ga ferromagnetic SMA micropillars, for example, demonstrated ... -
A Learning Approach To Sampling Optimization: Applications in Astrodynamics
(2013-08-01)A new, novel numerical optimization algorithm is developed, tested, and used to solve difficult numerical problems from the field of astrodynamics. First, a brief review of optimization theory is presented and common ... -
A Multiscale Framework for Predicting the Performance of Fiber/Matrix Composites
(2018-08-20)To enable higher fidelity studies of laminated and 3D textile composites, a scalable finite element framework was developed for predicting the performance of fiber/matrix composites across scales. Effective design paradigms ... -
A Multiscale Framework for the Characterization of Damage in Textile Composites Under Thermomechanical Loads
(2013-11-08)This work examines composite failure at multiple scales. The first scale that is examined is the fiber-matrix scale, where fibers and matrix are discretely modeled. A model is developed at this scale which includes ... -
A Real Time Expert Control System for Helicopter Autorotation
(2013-04-22)Autorotation maneuvers are required to perform a safe landing of a helicopter in cases of engine loss in a single engine vehicle and transmission or tail rotor malfunction. The rise of autonomous helicopter technology, and ... -
A Statistical Comparison Between Gibbs and Herrick-Gibbs Orbit Determination Methods
(2016-08-08)The detection, tracking, identification, and characterization (DTIC) of resident space objects (RSOs) is an important aspect of space situational awareness (SSA). Monitoring the space environment can prevent collisions and ... -
A Time-linearized Navier-Stokes Solver for Annular Gas Seal Rotordynamic Analysis
(2017-06-21)A time-linearized CFD solver for analyzing rotordynamics of gas seals is presented offering an improvement over existing linearized CFD solvers. Previous linearized solvers required structured grids and axisymmetric domains, ... -
Absolute and Relative Motion Satellite Theories for Zonal and Tesseral Gravitational Harmonics
(2018-05-08)In 1959, Dirk Brouwer pioneered the use of the Hamiltonian perturbation methods for constructing artificial satellite theories with effects due to nonspherical gravitational perturbations included. His solution specifically ... -
Accounting for Parameter Uncertainty in Reduced-Order Static and Dynamic Systems
(2012-02-14)Parametric uncertainty is one of many possible causes of divergence for the Kalman filter. Frequently, state estimation errors caused by imperfect model parameters are reduced by including the uncertain parameters as states ... -
Acoustics in the Klebanoff-Saric Wind Tunnel: Background Identification, Forcing, and Active Control
(2012-07-16)Low disturbance wind tunnels, such as the Klebanoff–Saric Wind Tunnel (KSWT), offer an ideal environment to study boundary layer transition. In particular, the leading-edge receptivity of sound can be measured by creating ... -
Active control of underwater propulsor using shape memory alloys
(Texas A&M University, 2007-04-25)The development of a leading edge propeller blade reconfiguration system using Shape Memory Allow (SMA) muscles is presented. This work describes the design and testing of a leading edge flap, which is used to alter the ... -
Active flow control in an advanced serpentine jet engine inlet duct
(2009-05-15)An experimental investigation was performed to understand the development and suppression of the secondary flow structures within a compact, serpentine jet engine inlet duct. By employing a variety of flow diagnostic ... -
Active Space Debris Removal using Capture and Ejection
(2013-04-25)Low Earth Orbit is over-cluttered with rogue objects that threaten existing technological assets and interfere with allocating new ones. Traditional satellite missions are not efficient enough to collect an appreciable ... -
Actuation Fatigue Characterization Methods and Lifetime Predictions of Shape Memory Alloy Actuators
(2017-05-05)Shape Memory Alloys (SMAs) are a class of intermetallic alloys that possess the ability to repeatedly sustain large amounts of deformation and recover a designed geometry through a thermal-induced, diffusionless, solid-to-solid ... -
Actuation Fatigue of Shape Memory Alloys
(2012-07-16)A testing method was developed to cycle quickly and repeatably Ni60Ti40 (wt. %) SMA specimens through temperature-induced transformation while under constant stress until failure. Previous works have shown fatigue cracks ...