To see the other types of publications on this topic, follow the link: Stability of airplanes – Testing.
Dissertations / Theses on the topic 'Stability of airplanes – Testing'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Stability of airplanes – Testing.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
van, Bronswijk N. "The effects of propeller power on the stability and control of a tractor-propeller powered single-engine low-wing monoplane." Thesis, The University of Sydney, 2001. https://hdl.handle.net/2123/27866.
Full textAbstract:
The development and operation of increasingly powerful military turboprop training aircraft is re-invigorating research into the analysis of the effects of propeller operation on aircraft stability and control.
2
Browne, Keith R. J. "The instrumentation and initial analysis of the short-term control and stability derivatives of an ASK-I3 glider." Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/3631.
Full textAbstract:
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2004.
220 leaves single printed pages ,preliminary pages i-xiv and numberd pages 1-188.Includes bibliography.list of figures and used a Hp Scanjet 8250 Scanner to pdf format (OCR),<br>ENGLISH ABSTRACT: This thesis describes the process followed to determine the short-term control and stability
derivatives of an ASK-13 glider (ZS-GHB). The short-term control and stability derivatives are
obtained by parameter estimation done using data recorded in flight. The algorithm used is the
MMLE3 implementation of a maximum likelihood estimator.
To collect the flight data sensors were installed in the ZS-GHB. Sensors measuring the
control surface deflections, translation acceleration, angular rates and the dynamic and static
pressure are needed to provide enough data for the estimation. To estimate accurate derivatives
specific manoeuvres were flown by the pilot, to ensure that all the modes of the glider were
stimulated.
The results reveal that the control and stability derivatives estimated from the flight data are
not very accurate but are still suitable to be used in simulating the glider's motion.<br>AFRIKAANSE OPSOMMING: Hierdie tesis beskryf die proses wat gebruik is om die kort periode beheer en stabiliteit afgeleides
van 'n ASK-13 sweeftuig vas te stel. Die kort periode beheer en stabiliteit afgeleides is
verkry deur parameter afskatting op data wat gedurend vlugte van die sweeftuig opgeneem is.
Die algoritme wat gebruik is om die parameters af te skat is die MMLE3 voorstelling van 'n
maksimale moontlikheid afskatter.
Om vlug data te versamel sensore moes in die sweeftuig geinstalleer word. Die sensore meet
beheer oppervlak hoeke, versnellings, hoeksnellhede en die dinamies en statiese lugdruk om te
verseker dat daar genoeg data is vir die afskatting. Om die afgeskatte parameters akkuraad te
kry moet die loods spesefieke manoeuvres vlieg om seker te maak dat al die moduse van die
sweeftuig is gestimuleer.
Die resultate wat gelewer is 'n stel kort periode beheer en stabiliteit afgeleides wat nie
akkuraad is nie, maar wat weI goed genoeg is or ie bewegings van die sweeftuig te simuleer.
3
Agenbag, Daniël Sarel. "Longitudinal handling characteristics of a tailless gull-wing aircraft." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-09182008-132941.
Full text
4
Nibbelink, Bruce D. "Finite-state inflow applied to aeroelastic flutter or fixed and rotating wings." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/13287.
Full text
5
Compton, Timothy James Shauck Maxwell Eustace. "Flight performance testing of ethanol/100LL fuel blends during cruise flight." Waco, Tex. : Baylor University, 2008. http://hdl.handle.net/2104/5150.
Full text
6
Rysdyk, Rolf T. "Adaptive nonlinear flight control." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/12108.
Full text
7
Seanor, Brad Alan. "Flight testing of a remotely piloted vehicle for aircraft parameter estimation purposes." Morgantown, W. Va. : [West Virginia University Libraries], 2002. http://etd.wvu.edu/templates/showETD.cfm?recnum=2631.
Full textAbstract:
Thesis (Ph. D.)--West Virginia University, 2002.<br>Title from document title page. Document formatted into pages; contains xviii, 203 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 197-199).
8
Piper, Ross H. "Design and testing of a combustor for a turbo-ramjet for UAV and missile applications." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FPiper.pdf.
Full textAbstract:
Thesis (M.S. in Aeronautical Engineering)--Naval Postgraduate School, March 2003.<br>Thesis advisor(s): Garth V. Hobson, Raymond P. Shreeve. Includes bibliographical references (p. 81-82). Also available online.
9
Riaz, Jamshed. "A simulation model of atmospheric turbulence for rotorcraft applications." Diss., Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/12940.
Full text
10
Foster, Tyler M. "Dynamic stability and handling qualities of small unmanned-aerial-vehicles /." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd643.pdf.
Full text
11
Bocvarov, Spiro. "Time-optimal reorientation maneuvers of an aircraft." Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07282008-135603/.
Full text
12
Nuhalt, Abdullah O. "Numerical simulation of feedback control of aerodynamic configurations in steady and unsteady ground effects." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/82627.
Full textAbstract:
A general numerical simulation of closely coupled lifting surfaces in steady and unsteady ground effects was developed. This model was coupled with the equations of motion to simulate aerodynamic-dynamic interaction. The resulting model was then coupled with a feedback-control law to form a general nonlinear unsteady numerical simulation of control of an aircraft in and out of ground effect.
The aerodynamic model is based on the general unsteady vortex-lattice method and the method of images. It is not restricted by planform, angle of attack, sink rate, dihedral angle, twist, camber, etc. as long as stall or vortex bursting does not occur. In addition, it has the versatility to model steady and unsteady aerodynamic interference. The present model can be used to simulate any prescribed flare and to model the effects of cross and/or head winds near the ground.
The present results show the influences of various parameters on the aerodynamic coefficients for both steady and unsteady flows. Generally, the ground increases the aerodynamic coefficients; the greater the sink rates, the stronger the effects. Increasing the aspect ratio increases both the steady and unsteady ground effects. An exception is a large aspect-ratio wing with large camber. The present results are generally in close agreement with limited exact solutions and experimental data.
In the aerodynamic-dynamic simulation, the equations of motion were solved by Hammlng's predictor-corrector method. The aircraft, air stream, and control surfaces were treated as a single dynamic system. The entire set of governing equations was solved simultaneously and interactively. The aerodynamic-dynamic model was used to study a configuration that resembles a Cessna 182 airplane. The ground lowers the effectiveness of the tail in controlling pitch, increases the lift and drag, and makes the hinge-moment less negative. Proportional and rate control laws were used in a feedback system to control pitch. One set of gains was used in and out of ground effect. For the same control input, the pitch angle responds faster and overshoots more near the ground than it does far from the ground. The present results demonstrate the feasibility of using the current simulation to model more complicated motions and the Importance of including the unsteady ground effects when analyzing the performance of an airplane during a landing maneuver.<br>Ph. D.
13
Stewart, Benjamin S. "Predicted scramjet testing capabilities of the proposed RHYFL-X expansion tube /." [St. Lucia, Qld], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18241.pdf.
Full text
14
Browne, Keith R. J. "The instrumentation and initial analysis of the short-term control and stability derivatives of an ASK-13 glider /." Link to the online version, 2004. http://hdl.handle.net/10019.1/3631.
Full text
15
Camposilvan, Erik. "Surface stability and small-scale testing of zirconia." Doctoral thesis, Universitat Politècnica de Catalunya, 2015. http://hdl.handle.net/10803/311627.
Full textAbstract:
Tetragonal polycrystalline zirconia stabilized with 3 mol% of yttria (3Y-TZP) is a biocompatible ceramic showing superior mechanical properties, which are partly the consequence of phase transformation: the tetragonal metastable phase can transform, with a net volume increase, to the stable monoclinic phase by a martensitic transformation. The transformation can be activated either mechanically by the application of high stresses, or chemically by the diffusion of water species, when the material is exposed to humid environment and moderate temperatures. In the first case, the local transformation at the crack tip under tension hinders their propagation, producing a phenomenon known as transformation toughening, which allows the design of damage-tolerant ceramics. On the other hand, the spontaneous and progressive surface transformation in presence of humidity represents an aging phenomenon known as low-temperature degradation (LTD), hydrothermal degradation or aging. Affecting a surface layer of only few micrometers, this phenomenon is accompanied by a substantial impairment of the surface integrity, representing a serious issue for the use of 3Y-TZP in load-bearing biomedical applications. It was shown in orthopedics that zirconia femoral heads used in arthroplasty may be vulnerable to LTD, leading in some cases to premature failures. Likewise, some recent publications devoted to dental zirconia have highlighted that it is susceptible to LTD if exact processing conditions are not followed.
The first subject of the thesis is the study of reliable solutions to avoid hydrothermal degradation of 3Y-TZP. Two novel methods are proposed, which allow a strong enhancement of the aging resistance through limited changes in the processing. These methods are based on co-doping the material from the surface with CeO2 by two different approaches. One includes infiltration of CeO2 precursors in the pre-sintered porous material. During thermal decomposition and sintering, CeO2 is trapped into the pores and diffused into 3Y-TZP, obtaining a functionally-graded material with decreasing CeO2 content from the surface to the bulk. The co-doping profile has been optimized by studying the pre-sintering, infiltration and sintering parameters in order to avoid a drop in the mechanical properties generally found in CeO2-doped zirconia. The second approach is applied to the dense material, where surface roughness has been created for adhesion or osseointegration purposes. After pressure infiltration of CeO2 precursors into the surface defects and pores created during the roughening process, a few-micrometers thick co-doped layer is obtained with a diffusion treatment. This helps sealing the surface defects and avoids hydrothermal degradation, without affecting the color or the mechanical properties, being so directly applicable in the manufacturing of dental crowns, abutments and dentures.
The second subject focuses on small-scale testing of zirconia near-surface regions. The existence of extrinsic size effects on the mechanical properties has been investigated, and the mechanical response of the degraded and non-degraded state has been compared in bending and compression. By testing micropillars and micro-cantilevers milled with focused ion beam (FIB), higher strength and strain at failure have been recorded with respect to the bulk state, as a result of transformation-induced plasticity and the absence of processing defects. No size effect has been found in terms of strength among small-scale samples, whereas the "yield" stress for phase transformation is lower for smaller samples. Hydrothermal degradation produces a microcrack network which controls the behavior and strongly impairs the mechanical properties of small-scale samples milled inside the degraded layer. In bending, a different response in terms of strength and stiffness has been measured depending on sample orientation, proving that that the induced damage is anisotropic.<br>El óxido de zirconio tetragonal estabilizado con 3 mol% de itria (3Y-TZP, o simplemente circona) es un material cerámico biocompatible de altas prestaciones mecánicas. Esto se debe, en parte, a la transformación de la fase tetragonal metastable en la fase monoclínica, acompañada por un incremento de volumen. Esta transformación martensítica se puede activar mecánicamente mediante esfuerzos elevados, o bien químicamente por la difusión de especies acuosas, cuando el material está expuesto a ambiente húmedo y temperaturas moderadas. En el primer caso, la transformación local que ocurre en la punta de las grietas bajo tensión permite el diseño de cerámicos tolerantes al daño (aumento de tenacidad por transformación). Por otra parte, la transformación espontánea y progresiva de la superficie en presencia de humedad es un fenómeno conocido como degradación hidrotérmica o envejecimiento. Aunque afecta una capa superficial de unas pocas micras, el envejecimiento reduce de manera substancial la integridad superficial, representando un problema para aplicaciones biomédicas estructurales. Se ha demostrado en ortopedia que las cabezas femorales de 3Y-TZP pueden ser vulnerables a la degradación hidrotérmica, llegando en algunos casos al fallo de la prótesis. En años recientes, la circona está siendo empleada en el campo dental, donde se ha visto que puede sufrir envejecimiento. La primera parte de esta tesis trata de desarrollar soluciones viables para evitar el envejecimiento. Se han propuesto dos nuevos métodos, que con pequeños cambios en el procesado permiten una fuerte mejora en la resistencia a la degradación. Estos están basados en el co-dopaje del material desde la superficie con CeO2 con dos estrategias diferentes. Una incluye la infiltración de precursores de CeO2 en el material presinterizado, que es poroso. Durante la descomposición térmica y el sinterizado, parte del CeO2 se queda atrapado en los poros y difunde en el retículo de la TZP, obteniendo un gradiente de composición con contenidos decrecientes de CeO2 desde la superficie hacia el interior. Se ha optimizado el gradiente estudiando los parámetros de pre-sinterizado, infiltración y sinterizado para evitar una posible caída en las propiedades mecánicas que se encuentra generalmente en la circona estabilizada con CeO2. La segunda estrategia se aplica en materiales densos donde se haya inducido rugosidad superficial para favorecer la adhesión o la osteointegración. Después de infiltrar a presión los precursores de CeO2 en los defectos y poros presentes en la superficie, se ha creado una capa co-dopada de pocas micras de espesor con un tratamiento de difusión. Esto contribuye en eliminar los defectos superficiales y evitar el envejecimiento sin modificar el color o las propiedades mecánicas, siendo directamente aplicable al procesado de coronas dentales, pilares y dentaduras postizas. La segunda parte de la tesis está enfocada en estudiar las las propiedades mecánicas de regiones superficiales de 3YTZP mediante ensayos de muestras microscópicas, para evaluar la presencia de efectos de escala y comparar la respuesta del material antes y después del envejecimiento. En micropilares y microvigas mecanizados con haz de iones focalizados se han medido resistencias y deformaciones de rotura mucho más altas que en probetas macroscópicas, gracias a la plasticidad inducida por deformación y a la ausencia de defectos de procesado. No se han encontrado efectos de escala entre las muestras microscópicas en cuanto a la resistencia, mientras que el límite de elasticidad donde aparece la transformación de fase es menor para muestras más pequeñas. El envejecimiento produce una red de microgrietas que controla el comportamiento y afecta las propiedades mecánicas de muestras microscópicas mecanizadas dentro la capa degradada. En flexión se ha medido una respuesta diferente en términos de resistencia y rigidez según la orientación, demostrando que el daño producido es anisotrópico
16
Blackler, Maxwell John. "Stability of silos and tanks under internal and external pressure." Thesis, School of Civil and Mining Engineering, 1986. http://hdl.handle.net/2123/14480.
Full text
17
Dagenhart, J. Ray. "Crossflow stability and transition experiments in a swept-wing flow." Diss., Virginia Tech, 1992. http://hdl.handle.net/10919/39084.
Full text
18
Obrist, Dominik. "On the stability of the swept leading-edge boundary layer /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/6767.
Full text
19
DeLaurentis, Daniel A. "A probabilistic approach to aircraft design emphasizing stability and control uncertainties." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/12948.
Full text
20
Svanberg, Craig E. "Biomimetic micro air vehicle testing development and small scale flapping-wing analysis /." Wright-Patterson Air Force Base, Ohio : Ft. Belvior, VA : Springfield, Va. : Air Force Institute of Technology, Graduate School of Engineering and Management ; Available to the public through the Defense Technical Information Center ; National Technical Information Service [distributor], 2008. http://www.dtic.mil/dtic/.
Full textAbstract:
Thesis (M.S. in Engineering and Management)--Air Force Institute of Technology, March 2008.<br>Title from reproduction cover. "March 2008." Thesis advisor: Dr. Mark Reeder. Performed by the Air Force Institute of Technology, Graduate School of Engineering and Management (AFIT/EN); sponsored by the Air Force Research Laboratory. Submitted in partial fulfillment of the requirements for the degree of Master of Science in Aeronautical Engineering from the Air Force Institute of Technology, March 2008.--P. [ii]. "AFIT/GAE/ENY/08-M27." Includes bibliographical references (p. 99-100). Also available online from the DTIC Online Web site.
21
Kapoor, Kalpesh. "Stability of test criteria and fault hierarchies in software testing." Thesis, London South Bank University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410587.
Full textAbstract:
Software testing is an important activity to verify and validate a system. A test criterion is a set of rules that are used for assessing the system under test. The effectiveness of a test criterion is measured in terms of its ability to reveal faults. Two key issues in software testing are: (a) effectiveness of test criteria in detecting faults, and (b) minimisation of test effort. These issues are studied empirically and formally within the framework of fault domain and test hypothesis. Typically, for a given test criterion, more than one test set may satisfy the criterion for a specification and implementation. A new notion of stability of test criteria is defined to assess the variation in effectiveness of test sets for a given test criterion. Experimental evaluation of stability is performed for various types of coverage such as condition coverage, decision condition coverage, full-predicate coverage, modified condition decision coverage and reinforced condition decision coverage. Fault detection effectiveness is also studied using a formal framework, which is applied to identify the conditions for the detection of various fault classes. It is shown that the number of test cases in a test set that can detect all hypothesised faults in an implementation depends on the complexity of the specification. One of the main difficulties with the fault-based testing approach is due to the large number of possible elements in a fault domain or that can be generated on the basis of a test hypothesis. To overcome this problem, various conditions to establish fault hierarchies that help to identify stronger faults are described. Here, the objective is to establish the relationship between faults such that detection of one fault guarantees the detection of another. The analysis of fault hierarchies is also shown to be useful in validating the coupling hypothesis, which states that if a test technique can detect an implementation with one fault, it can also detect the presence of multiple faults. The results obtained from the empirical and formal analysis provide an insight into earlier contradictory results regarding the effectiveness of test criteria. The formal framework helps in the classification of specifications and implementations in order to evaluate the effort required for testing; and the concept of fault hierarchy is useful in reducing test effort.
22
Ko, Joon Soo. "Analysis of the dynamic stability derivatives for high angle of attack aircraft." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/52300.
Full textAbstract:
Modern, high performance aircraft are required to be able to fly and be controlled over a wide variety of flight conditions. In order to predict the aircraft behavior and control requirements over the entire flight regime it is necessary to have a proper aerodynamic model. Flight conditions at high angles of attack lead to separated flows making the aerodynamic model more difficult to obtain. In this research wind tunnel experiments are performed on an F-5 air-craft model at high angles of attack, with small oscillations about the body oriented roll axis. In addition the free stream environment can be configured in one of three ways: l) straight uniform flow, 2) curved flow to simulated a horizontal turn, and 3) rolling flow to simulated a roll motion about the relative Velocity vector.<br>Ph. D.
23
Koutris, Andreas. "Testing for Structural Change: Evaluation of the Current Methodologies, a Misspecification Testing Perspective and Applications." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/26716.
Full textAbstract:
The unit root revolution in time series modeling has created substantial interest in non- stationarity and its implications for empirical modeling. Beyond the original interest in trend vs. di¤erence non-stationarity, there has been renewed interest in testing and modeling structural breaks. The focus of my dissertation is on testing for departures from stationarity in a broader framework where unit root, mean trends and structural break non-stationarity constitute only a small subset of the possible forms of non-stationarity. In the fi¦rst chapter the most popular testing procedures for the assumption, in view of the fact that general forms of non-stationarity render each observation unique, I develop a testing procedure using a resampling scheme which is based on a Maximum Entropy replication algorithm. The proposed misspecification testing procedure relies on resampling techniques to enhance the informational content of the observed data in an attempt to capture heterogeneity 'locally' using rolling window estimators of the primary moments of the stochastic process. This provides an e¤ective way to enhance the sample information in order to assess the presence of departures from stationarity. Depending on the sample size, the method utilizes overlapping or non-overlapping window estimates. The e¤ectiveness of the testing procedure is assessed using extensive Monte Carlo simulations. The use of rolling non-overlapping windows improves the method by improving both the size and power of the test. In particular, the new test has empirical size very close to the nominal and very high power for a variety of departures from stationarity. The proposed procedure is then applied on seven macroeconomic series in the fourth chapter. Finally, the optimal choice of orthogonal polynomials, for hypothesis testing, is investigated in the last chapter.<br>Ph. D.
24
Woelfer, Karl Alan 1952. "A high speed network architecture for real time testing of an embedded computer system." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277189.
Full textAbstract:
The Embedded Computer System Support Improvement Program, or ESIP, was begun by the U.S. Air Force in 1983 to find new cost effective ways of integrating, testing and maintaining the computers embedded in military airborne, spaceborne, and ground electronic systems. A major initiative of this program is the Extendable Integration Support Environment (EISE). The EISE project involves design and development of a high speed network-based hardware and software integration and test environment. The ongoing work is being done jointly by U.S. Air Force civilian engineers at McClellan Air Force Base and TRW in Sacramento, California, in support of embedded avionics computers in the A-10 aircraft. The prototype design will be used to test and integrate various other aircraft and space systems. The author was the EISE project lead system engineer from July 1986 through January 1988.
25
Okafor, Chinedum Oluchukwu. "Formulation and stability testing of eye drop preparations containing phenylephrine hydrochloride." Thesis, Nelson Mandela Metropolitan University, 2012. http://hdl.handle.net/10948/d1020985.
Full textAbstract:
Phenylephrine hydrochloride is a potent adrenergic agent and β-receptor sympathomimetic drug, used in its optically active form (Pandey et al., 2003; Pandey et al., 2006). As an α1-adrenergic receptor agonist, phenylephrine hydrochloride is used ocularly as a decongestant for uveitis and as an agent to dilate the pupil (Lang, 1995). High intraocular doses have been reported to cause tachycardia, hypertension, and headache. These side effects are caused by large amounts of the drop draining into the nasal cavity. Eye drops that contain phenylephrine hydrochloride have proven to have low intra-ocular bioavailability because of a short contact time with the eyes which reduces the amount of drug reaching the site of action. Formulations of phenylephrine hydrochloride eye drops have varying shelf-lives of approximately two to four years. The aim of this study was to formulate and manufacture an eye drop product containing phenylephrine hydrochloride. Important characteristics that were targeted were increased ocular absorption by increasing the viscosity of the product and reduced degradation of phenylephrine hydrochloride. A variety of phenylephrine hydrochloride formulations were manufactured on a laboratory scale using hydroxypropyl methylcellulose (HPMC), glycerol, and sodium carboxy methylcellulose as viscosity modifying agents (VMA). The concentration of phenylephrine hydrochloride was ten percent. Ten millimeters of each formulation was made in triplicate. The quantity in each was evaluated using a previously validated high performance (pressure) liquid chromatography method. Physicochemical properties including pH and colour were also evaluated. Stability was assessed using real time and accelerated stability conditions in accordance with the International Conference on Harmonization (ICH) guidelines. Formulations containing hydroxypropyl methylcellulose (HPMC) as the viscosity modifying agents proved to be stable under all storage conditions when compared with formulations containing other viscosity modifying agents (VMA). However, sodium citrate dihydrate; sodium metabisulphite and EDTA also stabilized the formulations to a certain extent Changes in the appearance and colour of products containing glycerol under accelerated storage conditions were observed. The sodium carboxy methylcellulose (SCMC) containing formulation was found to be physically and chemically stable in two conditions, namely 30 °C/65 percent RH and 25 °C/60 percent RH. The formulations containing hydroxypropyl methylcellulose along with an antioxidant showed to be most stable as it remained aesthetically pleasing did not change colour and did not have a reduction in phenylephrine hydrochloride concentrations. This meant that phenylephrine hydrochloride did not degrade while the viscosity modifying agents remained stable. Rheological tests showed differences in the viscosities of the formulations as glycerol had increased in viscosity over time while HMPC and SCMC displayed relative similarities. The formulations were compared to a marketed eye drop containing polyvinyl alcohol as a VMA. After rheological analysis the formulation containing HPMC displayed better viscosity than the product with polyvinyl alcohol. The preservatives in the formulations were active against the microbial organisms use to challenged them.
26
Hekkala, Cathrine. "Outdoor Stability Testing of Printed Organic Solar Cells for Indoor Applications." Thesis, Karlstads universitet, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-78676.
Full textAbstract:
Renewable energy is required for a sustainable future and one way to meet this is with organic solar cells (OSCs). The OSC can be easily manufactured at a low cost, be lightweight and be used on flexible surfaces. If the efficiency in high illumination intensities and stability in harsh environments increase for OSCs, they can com- pete with the other technologies even in outdoor conditions. Another advantage of OSCs is their good performance under low-light and indoor conditions. This is utilized by Epishine, a Swedish company based in Linköping working with small, thin and flexible organic printed solar cells optimized for indoor applications. The goal of this thesis is to determine how Epishine’s solar cells for low-light indoor usage work in more challenging conditions and to identify which are the factors that are detrimental for the lifetime of the cells. The result showed that all modules had a similar initial electrical performance which indicates that the modules have high reproducibility and degradation in darkness is negligible (since the initial measurements were made at different times). The tests showed that the temperature affected the modules. The test in the oven showed a little less than half the degradation compared to tests under the solar simulator, although both tests were subjected to the same temperature. The hu- midity test and the test exposed to LED-light showed almost no degradation. For the levels exposed to the sun or simulated sunlight, the decrease of the short circuit current density shows a burn-in time, which is typical for organic solar cells. After the first couple of hours, the decrease slows down to a more linear behaviour. All modules that were exposed to bright light also showed some recovery effect for short circuit current density and efficiency after they have been kept in the dark. It would be interesting to investigate the behaviour of the modules after even more exposure and look into how the recovery effect works.
27
Clements, Jeremy Peter. "Design and development of pre-clinical hip stem stability testing methods." Thesis, University of Bath, 2006. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432404.
Full text
28
Recktenwald, Bryan David Ahmed Anwar. "Aerodynamic testing of a circular planform concept aircraft." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SUMMER/Aerospace_Engineering/Thesis/Recktenwald_Bryan_48.pdf.
Full text
29
Kannappan, Laxmikant Aerospace Civil & Mechanical Engineering Australian Defence Force Academy UNSW. "Damage detection in structures using natural frequency measurements." Awarded by:University of New South Wales - Australian Defence Force Academy. Aerospace, Civil & Mechanical Engineering, 2009. http://handle.unsw.edu.au/1959.4/44852.
Full textAbstract:
In the last two decades, the emphasis in aircraft maintenance has been on developing online structural health monitoring systems to replace conventional non destructive inspection techniques which require considerable down-time, human effort and cost. Vibration based damage detection is one of the most promising techniques for implementation in Structural Health Monitoring (SHM). In vibration based methods, the presence of damage is detected by monitoring changes in one of the dynamic parameters of the structure, resonant frequencies, modeshapes or damping characteristics. Compared to modeshape based methods, frequency based methods have the advantage that measurements need to be taken only at a single location. Previous developments on frequency based techniques have relied on Finite Element Model updating; analytical techniques have hitherto been restricted to beams due to the complexity in developing equations for cracked two dimensional structures. In this thesis the analytical approach using an energy formulation is extended to plates with through-thickness cracks, where modeshapes from either numerical modelling or experimental measurements can be employed to determine the energy of vibration. It is demonstrated that by using a hybrid approach, incorporating experimentally measured modeshapes along with measured changes in frequencies, the damage parameters can be estimated without resorting to theoretical modelling or numerical analysis. The inverse problem of finding the crack location, size and orientation from measured changes in frequencies is addressed using minimisation techniques. The forward problem and the inverse algorithm is first validated using numerical simulation and experimental testing of beams with edge cracks and centre cracks. The application of the methodology to the two dimensional case is then validated by numerical simulation and experimental modal analysis of plates with through thickness cracks. A statistical procedure is developed for determination of the 90/95 probability of crack detection and the minimum detectable crack size in both cases. It is demonstrated that the measurement of frequency changes can be successfully employed to detect and assess the location and size of cracks in beams and plates, using modeshapes from theory, Finite Element Analysis.
30
Eldred, Lloyd B. "Sensitivity analysis of the static aeroelastic response of a wing." Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/40147.
Full textAbstract:
A technique to obtain the sensitivity of the static aeroelastic response of a three dimensional wing model is designed and implemented. The formulation is quite general and accepts any aerodynamic and structural analysis capability. A program to combine the discipline level, or local, sensitivities into global sensitivity derivatives is developed. A variety of representations of the wing pressure field are developed and tested to determine the most accurate and efficient scheme for representing the field outside of the aerodynamic code. Chebyshev polynomials are used to globally fit the pressure field. This approach had some difficulties in representing local variations in the field, so a variety of local interpolation polynomial pressure representations are also implemented. These panel based representations use a constant pressure value~ a bilinearly interpolated value, or a biquadratic ally interpolated value. The interpolation polynomial approaches do an excellent job of reducing the numerical problems of the global approach for comparable computational effort. Regardless of the pressure representation used, sensitivity and response results with excellent accuracy have been produced for large integrated quantities such as wing tip deflection and trim angle of attack. The sensitivities of such things as individual generalized displacements have been found with fair accuracy. In general, accuracy is found to be proportional to the relative size of the derivatives to the quantity itself.<br>Ph. D.
31
Vasudevan, Gopal. "Fuel optimal rendezvous including a radial constraint." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/94484.
Full textAbstract:
Fuel-optimal rendezvous in orbit is examined using thrust-impulses and coasting arcs. Necessary conditions for the optimality of fuel-optimal rendezvous with and without radial constraints are derived. These conditions are then used to verify the optimality of trajectories obtained from a parameter-optimization technique.
For rendezvous problems with radial constraint, locally optimal trajectories include constrained arcs or touch-point arcs. Numerical procedures to compute the costates and the jumps in the costates at the touch point and at the entry point to the constraint arc are provided. Locally optimal solutions for non-optimal trajectories with a minimum radius-constraint are obtained using criteria due to Lion and Handelsmann.
Numerical solutions show that multiple-impulse trajectories almost always result in a lower cost function than the corresponding two impulse trajectories. It is also observed that trajectories comprised of only touch-point arcs can often be improved by using an additional impulse.<br>M. S.
32
Lam, Yee-man, and 林綺雯. "GIS in aircraft noise exposure assessment, Tsuen Wan district, Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B29961324.
Full text
33
Archibald, Timothy, Stacy Brown, and Alexei Gonzalez-Estrada. "Refrigerated Stability of Diluted Succinylcholine, Pancuronium, and Atracurium." Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/88.
Full textAbstract:
Refrigerated Stability of Diluted Succinylcholine, Pancuronium, and Atracurium.
T. Archibald1, S. Brown1, A. Gonzalez-Estrada2
1College of Pharmaceutical Sciences, Bill Gatton College of Pharmacy, East Tennessee State University, Johnson City, TN2Quillen College of Medicine, Allergy and Clinical Immunology, East Tennessee State University, Johnson City, TN
The purpose of this study is to investigate the stored stability of dilutions of neuromuscular blocking agents (NMBAs), namely succinylcholine, pancuronium, and atracurium, for skin prick/intradermal testing.
Concentrations of NMBAs were monitored by liquid chromatography-mass spectrometry (LC-MS/MS) for a period of 14 days. Dilutions of NMBAs were prepared in saline by factors of 10x, 100x, 1,000x, 10,000x, and 100,000x as sensitivity of the assay allowed. Each drug was prepared with an n = 5 for each dilution, using a different newly opened product for each series. Diluted drug products were stored in a laboratory refrigerator until sampling. On sampling days (day 0, 1, 2, 4, 7, and 14), one milliliter aliquots of each dilution were removed, filtered, and analyzed against freshly prepared set of reference dilutions.
The results are expressed as beyond use date (BUD), defined as recovery of drug versus the reference (90-110%). Based on the LC-MS/MS data, the BUD for succinylcholine diluted by 10x and 100x is 48 and 24 hours, respectively. The1000x dilution is also stable for 24 hours.Higher dilutions of succinylcholine (10,000x to100,000x) should be used immediately following preparation (within less than 24 hours), as the potency of these dilutions had decreased below 90% at the 24 hr sampling. .Pancuronium diluted by 10x and 100x, had a BUD of 48 hours, and the1,000x dilution was stable for 24 hours.As with the succinylcholine, the 10,000x and 100,000x dilutions expressed potency of <90% at 24 hours. .Atracurium diluted to 10x had a BUD of 96 hours, the100x dilution is stable for 24 hours yet higher dilutions (1,000x to 10,000x) do not persist beyond 24 hours. . The 100,000x dilution of atracurium was unknown, given than the signal intensity was too weak to monitor by our LC-MS/MS method.
With increasing dilution factors, the stability of these drugs in saline decreases, associated with an increasing deviation between samples and freshly prepared references. The most stable dilutions for each of the drugs tested were 10x and 100x. Stability of these drugs is likely compromised by hydrolysis of the ester bonds in the drug molecules.
34
Gillett, Susan Gille 1957. "AN EXAMINATION OF SEARCH ROUTINES USED IN SLOPE STABILITY ANALYSES." Thesis, The University of Arizona, 1987. http://hdl.handle.net/10150/276433.
Full textAbstract:
Slope stability analyses are commonly performed using computer programs hich perform safety factor calculations using limit equilibrium solutions and search for the critical, or most probable failure surface. These searches are always performed using "direct search" techniques, which are the simplest but least efficient optimization methods. In the future, more advanced optimization algorithms will be incorporated into existing slope stability programs, which will greatly increase the speed with which the search converges to the critical slip surface. The relative efficiency and reliability of these new search strategies must be established by comparative testing on a variety of slope problems. This paper presents a set of problems that will serve as a basis for future comparative testing of different optimization procedures. These problems span the range of slope problems encountered by geotechnical engineers. Baseline measures of efficiency are obtained using an existing slope stability program with grid and pattern search capabilities.
35
Dean, Brian J. "Aviation selection testing : the effect of minimum scores on minorities /." Thesis, access online version, 1996. http://handle.dtic.mil/100.2/ADA307314.
Full text
36
Patterson, Jay Reynolds Medhurst Martin J. "Testing foreign policy apologia a rhetorical analysis of the Hainan Incident /." Waco, Tex. : Baylor University, 2009. http://hdl.handle.net/2104/5333.
Full text
37
Gonzalez, Blohm Sabrina Alejandra. "Biomechanical Testing on Cadaveric Spines for Different Treatments that Affect Lumbar Stability." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4052.
Full textAbstract:
Stenosis is one of the most common causes for spinal surgery. Laminectomy decompression and fusion are surgical procedures prescribed for this condition. The intention of this work was to investigate the effects of a laminectomy decompression, followed by fusion, on a lumbar functional spinal unit (FSU) through in vitro dynamic (±8Nm at 0.125Hz) and quasi-static (±7.5Nm at 0.1Hz) biomechanical tests, for flexion, extension, bending and rotation motions.
Six FSUs where disarticulated from four human cadaveric lumbar spines (63 ± 12 years) and were tested under the following sequence: (1) intact, (2) laminectomy decompression, and (3) Pedicle Screw System (PSS), using a load-displacement controlled system. Dynamic neutral zone (NZ), dynamic neutral zone stiffness (NZS) and the range of motion (ROM) were the parameters evaluated.
Since only 6 FSUs from different spinal levels were used, any effect related to the spinal level could not be evaluated. This limitation enforced to consider normalized data (with respect to intact) as an alternative analysis, but large standard deviations after transforming the data forced us to contemplate this "a pilot study".
Dynamic testing revealed that there were no significant differences in the neutral zone magnitude for any motion after a laminectomy decompression, while its magnitude for flexion-extension was significantly affected by PSS treatment (p<0.004). The change in dynamic NZ (normalized data) was significantly different (p<0.03) after both treatments for flexion-extension motion. The reduction in stiffness (normalized data) for extension after a laminectomy, and the increase in stiffness (normalized data) for flexion and extension after PSS treatment, were both significant (p<0.03 and p<0.05, respectively). The ROM were not statistically significant for the three treatments, but normalized data showed significant differences (p<0.05) for all motions, except for right bending after laminectomy and right rotation after PSS.
Non-normalized data from quasi-static testing didn't show any statistically significant difference between the treatments for any motion. Normalized data suggested significant differences for the change in ROM for all motions at multiple load conditions, especially for flexion and extension.
This pilot study suggests there may be a considerable effect of a laminectomy on the stability of a lumbar FSU. Dynamic data suggested the changes in neutral zone stiffness triggered by a laminectomy procedure may be significant for extension. PSS treatment increased segment's NZ stiffness by more than double. The changes in ROM from quasi-static loading caused by a laminectomy decompression may be significant as well, especially for flexion (20%) and extension (greater than 10%).
It is suggested that further studies involving spine biomechanics should consider and report, but not be limited to the following variables: exposure time of the specimen to room temperature, preservation and testing conditions, ligaments and joints conditions, testing protocol, and loading history.
38
Martin, Colin Patrick. "A basis for dynamic stability testing of agricultural vehicles for hillside use." Thesis, University of Edinburgh, 1995. http://hdl.handle.net/1842/12584.
Full textAbstract:
Life, limb and money continues to be lost in agriculture world-wide as a result of vehicles overturning on sloping land. It appears that vehicle operators lack the information required to prevent this. Studies of overturning accidents on hillsides have suggested that overturning is often the result of dynamic vehicle behaviour and in particular the result of striking discrete terrain obstacles. Currently, the only standard measure of the stability of vehicles for hillside use is the static stability limit. Several researchers have studied the response of vehicles striking discrete obstacles and have computed reductions in safe slope with increases in speed or obstacle height. However, there are many variables influencing the vehicle response; and no 'dynamic stability' test has been proposed and adequately backed up with theoretical analysis. This thesis describes work to provide more insight into the complex problem of vehicle dynamic stability, leading to a proposal for a dynamic stability test. A DADS computer model has been developed and validated by comparison with a farm trailer constrained on a test rig, with test variables speed, slope, tyre pressure, moment of inertia, static wheel load, static stability limit and obstacle length. It was found in both empirical and simulated cases that the trailer response reached a maximum at a certain speed, dependent on the natural frequency of the system, and that the overturning slope was at a minimum at that speed. The completed model predicted the slope on which the trailer overturned to within 27% of the slope in 95% of cases. Attaining this level of accuracy involved a detailed study of tyre properties, especially radial stiffness. It was found, unexpectedly, that this decreased by around 50% during large amplitude dynamic compression such as occurs when striking an obstacle. The relationship between the proposed index and the vehicle parameters was studied and it was found that static wheel load and tyre stiffness affected it most significantly. The index appeared to increase with the square root of the tyre stiffness and decrease with the square root of the static wheel load. The index could be used in conjunction with the static stability limit to compute a slope below which it would be theoretically safer to use the more dynamically stable vehicle.
39
Kidd, David Alan 1956. "In situ testing of Gila Conglomerate with application to probabilistic slope stability." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277060.
Full textAbstract:
In this study the shear strength parameters for a consolidated, well-cemented boulder conglomerate at the Cyprus Miami Copper Mine are determined by a newly developed field test. The values obtained are used to investigate the probability of failure of pit slopes cut into the conglomerate. Any boulder conglomerate is impossible to test accurately with conventional laboratory techniques due to its large particle sizes and the destruction of cementation by conventional sampling methods. For these reasons a simple in situ test was developed which could be used in conjunction with laboratory techniques and analytical procedures to estimate the in situ strength properties of the Gila Conglomerate. The variability in the testing of the shear strength parameters of Gila Conglomerate make a probabilistic approach to design appropriate.
40
Harman, Alex Bruce Mechanical & Manufacturing Engineering Faculty of Engineering UNSW. "Optimisation and improvement of the design of scarf repairs to aircraft." Awarded by:University of New South Wales. School of Mechanical and Manufacturing Engineering, 2006. http://handle.unsw.edu.au/1959.4/26788.
Full textAbstract:
Flush repairs to military aircraft are expected to become more prevalent as more thick skin composites are used, particularly on the surface of the fuselage, wings and other external surfaces. The use of these repairs, whilst difficult to manufacture provide an aerodynamic, ???stealthy??? finish that is also more structurally efficient than overlap repairs. This research was undertaken to improve the design methodology of scarf repairs with reduced material removal and to investigate the damage tolerance of scarf repair to low velocity impact damage. Scarf repairs involve shallow bevel angles to ensure the shear stress in the adhesive does not exceed allowable strength. This is important when repairing structures that need to withstand hot and humid conditions, when the adhesive properties degrade. Therefore, considerable amounts of parent material must be machined away prior to repair. The tips of the repair patch and the parent laminate are very sharp, thus a scarf repair is susceptible to accidental damage. The original contributions include: ??? Developed analytic means of predicting the stresses within optimised scarf joints with dissimilar materials. New equations were developed and solved using numerical algorithms. ??? Verified using finite element modelling that a scarfed insert with dissimilar modulus subjected to uniaxial loading attracted the same amount of load as an insert without a scarf. As such, the simple analytic formula used to predict load attraction/diversion through a plate with an insert may be used to predict the load attraction/diversion into a scarf repair that contains a dissimilar adherend patch. ??? Developed a more efficient flush joint with a doubler insert placed near the mid line of the parent structure material. This joint configuration has a lower load eccentricity than external doubler joint. ??? Investigated the damage tolerance of scarf joints, with and without the external doubler. The results showed that scarf joints without external doublers exhibited a considerable strength reduction following low velocity impact. Based on the observations, the major damage mechanics in the scarf joint region following impact have been identified. These results demonstrated that it is important to incorporate damage tolerance in the design of scarf repairs.
41
Maki, Brian Edward. "A posture control model and balance test for the prediction of relative postural stability, with special consideration to the problem of falling in the elderly." Thesis, University of Strathclyde, 1987. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21488.
Full textAbstract:
A balance testing methodology was developed, based on a posture control model which defines relative stability by the degree to which a transient postural perturbation would cause the centre-of-pressure on the feet to approach the limits of the base-of-support. To minimize anticipatory adaptations and to ensure subject safety, the balance test used a small-amplitude continuous random or pseudorandom perturbation. The data were used to identify an input-output model, which was then used to predict large-amplitude transient response. The test perturbation was an anterior-posterior acceleration of a platform on which the subject stood. Pilot experiments were performed to determine appropriate perturbation parameters. Testing of sixty-four normal subjects demonstrated highly significant ageing-related decreases in predicted stability. No significant sex-related differences were found. Predicted stability increased when the subjects were blindfolded. In using the balance test to identify balance-impaired individuals, the blindfolded results and the eyes-open/blindfolded ratio provided higher success rates than the eyes-open results. Depending on the modelling method used, the balance test was able to identify up to three of five vestibular patients and five of five elderly fallers, at a false positive rate of 25% in the normal subjects. Correlations between the balance test results and measures of spontaneous postural sway were weak, except in the normal young adult subjects. Comparison with transient tests showed the balance test to yield reasonably accurate predictions of small-amplitude transient response, but to overestimate the large-amplitude response; however, the transient test results may have been confounded by adaptive effects. It was concluded that the balance test provides a sensitive functional measure of the changes in postural control that are known to occur in ageing. Although it shows promise as a tool for identifying balance impairments, larger numbers of balance-impaired subjects must be tested.
42
Abtahi, Ali A. "Aspect ratio effects on wings at low Reynolds numbers." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/52330.
Full textAbstract:
In this study the primary objective was to determine the effect of aspect ratio in particular and in general the effect of three dimensionality on the flow around wings at low Reynolds numbers. It was seen that the effects observed at high Reynolds number are also present in this Re range. There is the usual increase in lift slope and this increase can even be predicted with reasonable accuracy using Prandtl's lifting line theory. In addition to the change in lift slope the zero lift angle of attack was also influenced by the aspect ratio.
Through flow visualization it was ascertained that the wingtips have a rather restricted effect on the laminar separation bubble. The disappearance of the bubble extends only for a small distance inboard from the tips.
The size of the hysteresis loop and the Reynolds number at which hysteresis starts was found to be influenced by the aspect ratio.
The momentum deficit method was used to validate the data obtained by the strain gauge method and there was adequate agreement between the values found through the two methods.
From the measurements of pressure done around the airfoil contour one could determine both the location of the laminar separation bubble and the regions were flow is separated. The pressure taps themselves were found to influence measurements somewhat in certain regions of angle of attack and Reynolds number.
In the future it would be beneficial to continue strain gauge measurements on this airfoil with flaps and control surfaces to determine their effect on the formation of the laminar separation bubble. Also measurements on other shapes would give more insight into the phenomena occurring here. The effects of turbulence and noise will have to be investigated in detail to determine what performance to expect from an actual aircraft. Finally detailed measurements on boundary layer stability and its effect on the occurrence of reattachment should be studied in detail to gain insight into the reasons for the presence of a hysteresis loop in stall at these Reynolds numbers.<br>Ph. D.
43
Murch, Austin Matthew. "Aerodynamic Modeling of Post-Stall and Spin Dynamics of Large Transport Airplanes." Thesis, Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/18855.
Full textAbstract:
This work addressed aerodynamic modeling methods for prediction of post-stall flight dynamics of large transport aircraft. This was accomplished by applying historically successful modeling methods used on high-performance military aircraft to a transport configuration. The overall research approach involved integrating forced oscillation and rotary balance wind tunnel data into an aerodynamic model using several methods of blending these data. The complete aerodynamic model was integrated into a six degree-of-freedom simulation. Experimental data from free-spin wind tunnel testing was used to validate the aerodynamic modeling methods by comparing aerodynamic force and moment coefficients and also to validate the simulation performance by comparing spin mode characteristics and time histories. The aerodynamic model prediction of spin dynamics was generally very good using all of the blending methods studied. In addition, key spin mode characteristics were predicted with a high degree of accuracy. Overall, using the Hybrid Kalviste method of blending forced oscillation and rotary balance data produced the closest match to the free-spin data when comparing aerodynamic coefficients and spin mode characteristics. Several issues were encountered with the blending methods that were exacerbated by nonlinearities and asymmetries in the dynamic aerodynamic data. A new method of looking up dynamic aerodynamic data was proposed to address shortcomings in the blending methods and recommendations were provided on addressing issues with the dynamic aerodynamic data.
44
Scamps, Alexander. "Development of a Variable Stability Flight Simulation Facility Re-engineering of Flight Control Loading and Motion Systems." Thesis, The University of Sydney, 2003. http://hdl.handle.net/2123/567.
Full textAbstract:
A Variable Stability Flight Simulator is being developed in the School of Aerospace, Mechanical and Mechatronic Engineering at the University of Sydney, Australia. The device is being developed both as a teaching tool for use in flight mechanics courses in the department and as a research tool. It is reasonable to state that learning is enhanced through the experience of concepts outside of the classroom environment. It is intended that the device will be integrated into the department�s teaching program in aircraft flight mechanics. Initial studies centred around a PC based flight simulation developed at the Cranfield College of Aeronautics in the United Kingdom. This system utilises a distributed architecture with several computers connected via Ethernet. It also employs a Primary Image three channel visual system. The system has been further enhanced by the addition of a Link flight simulator provided by the Royal Australian Air Force (RAAF). The RAAF had been using the simulator as a training tool for some years until it had become surplus to requirements. Most of the work in the project has centred around re-engineering this simulator into a viable research/education tool. The Cranfield system has been incorporated into the Link simulator�s hardware to provide a fixed base simulation. The majority of the work described in this thesis revolved around the re-engineering of the flight control loading and motion systems. Previously these items were controlled by analogue circuitry with minimal digital interfaces to the main simulation software. The systems have been re-designed to replace much of the single model analogue circuitry with re-configurable digital control software. Doing so allows changes to be made to the systems in real time through a software interface. The software resides on a common computer that extensively interfaces with the rest of the simulation. To support the hardware involved and to provide for system operation and safety, an extensive Supervisory system has also been implemented. This system along with the motion and control loading software has been implemented in the Matlab / Real-Time Workshop environment. This gives the capability of making real-time changes to any part of the overall simulation. A variable stability module (vsm) is under development. The addition of this module will allow changes to be made to the simulation itself in real-time. The simulator is now functional with the motion and control loading systems operating as designed. Tuning of both systems has been done subjectively by the author. An initial objective analysis of the motion system has been undertaken in an attempt to verify the fidelity of the motion cues generated. A significant outcome of this project has been to create a safe, easily maintainable, re-configurable flight simulator from a large, complex, legacy system. The facility now forms a significant research and teaching tool in areas such as flight mechanics, propulsion, aircraft handling qualities and human factors.
45
Scamps, Alexander. "Development of a Variable Stability Flight Simulation Facility Re-engineering of Flight Control Loading and Motion Systems." University of Sydney. Aerospace, Mechanical, 2003. http://hdl.handle.net/2123/567.
Full textAbstract:
A Variable Stability Flight Simulator is being developed in the School of Aerospace, Mechanical and Mechatronic Engineering at the University of Sydney, Australia. The device is being developed both as a teaching tool for use in flight mechanics courses in the department and as a research tool. It is reasonable to state that learning is enhanced through the experience of concepts outside of the classroom environment. It is intended that the device will be integrated into the department�s teaching program in aircraft flight mechanics. Initial studies centred around a PC based flight simulation developed at the Cranfield College of Aeronautics in the United Kingdom. This system utilises a distributed architecture with several computers connected via Ethernet. It also employs a Primary Image three channel visual system. The system has been further enhanced by the addition of a Link flight simulator provided by the Royal Australian Air Force (RAAF). The RAAF had been using the simulator as a training tool for some years until it had become surplus to requirements. Most of the work in the project has centred around re-engineering this simulator into a viable research/education tool. The Cranfield system has been incorporated into the Link simulator�s hardware to provide a fixed base simulation. The majority of the work described in this thesis revolved around the re-engineering of the flight control loading and motion systems. Previously these items were controlled by analogue circuitry with minimal digital interfaces to the main simulation software. The systems have been re-designed to replace much of the single model analogue circuitry with re-configurable digital control software. Doing so allows changes to be made to the systems in real time through a software interface. The software resides on a common computer that extensively interfaces with the rest of the simulation. To support the hardware involved and to provide for system operation and safety, an extensive Supervisory system has also been implemented. This system along with the motion and control loading software has been implemented in the Matlab / Real-Time Workshop environment. This gives the capability of making real-time changes to any part of the overall simulation. A variable stability module (vsm) is under development. The addition of this module will allow changes to be made to the simulation itself in real-time. The simulator is now functional with the motion and control loading systems operating as designed. Tuning of both systems has been done subjectively by the author. An initial objective analysis of the motion system has been undertaken in an attempt to verify the fidelity of the motion cues generated. A significant outcome of this project has been to create a safe, easily maintainable, re-configurable flight simulator from a large, complex, legacy system. The facility now forms a significant research and teaching tool in areas such as flight mechanics, propulsion, aircraft handling qualities and human factors.
46
Msomi, Velaphi. "Modelling and testing smart aileron servo tabs : developing simulation tools for smart materials." Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2150.
Full textAbstract:
Thesis (DTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2015.<br>This dissertation addresses the development and the testing of a simulation tool to be used to predict the behaviour of smart material/structures. Along with the development of the simulation tool, a new form of the model describing the behaviour of shape-memory alloy was developed and implemented. The proposed model was developed based on the existing cosine model, conventionally used in literature, but it uses hyperbolic tangent functions. The hyperbolic tangent function was chosen so as to allow the simulation of any range of temperatures. Experiments were performed to obtain the parameters to be used in the simulation and to validate the numerical results. Two different simulations were performed: a one dimensional FEA analysis with a two dimensional orientation (NiTi SMA wire simulation) and a three dimensional FEA analysis (NiTi SMA plate) [Msomi and Oliver, 2015]. Alongside the FEA analysis, two experiments were performed with the purpose of obtaining the material parameters to be used in FEA analysis and to compare the FEA results to the experimental results.<br>Airbus Company
47
Niu, Kangmin. "Compressive behavior of sandwich panels and laminates with damage." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/12056.
Full text
48
Kumar, Dharmendra. "A COMPUTATIONALLY EFFICIENT METHOD OF ANALYZING THE PARAMETRIC SUBSTRUCTURES." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275395.
Full text
49
Aitcheson, Kent Robert. "Stability and control flight testing of a half-scale Pioneer remotely piloted vehicle." Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/28561.
Full text
50
Kahle, Nicole L. "The Effects of Core Stability Training on Balance Testing in Young, Healthy Adults." University of Toledo Honors Theses / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=uthonors1245863136.
Full text