Matching Items (198)
Description
This study focuses on implementing probabilistic nature of material properties (Kevlar® 49) to the existing deterministic finite element analysis (FEA) of fabric based engine containment system through Monte Carlo simulations (MCS) and implementation of probabilistic analysis in engineering designs through Reliability Based Design Optimization (RBDO). First, the emphasis is on experimental data analysis focusing on probabilistic distribution models which characterize the randomness associated with the experimental data. The material properties of Kevlar® 49 are modeled using experimental data analysis and implemented along with an existing spiral modeling scheme (SMS) and user defined constitutive model (UMAT) for fabric based engine containment simulations in LS-DYNA. MCS of the model are performed to observe the failure pattern and exit velocities of the models. Then the solutions are compared with NASA experimental tests and deterministic results. MCS with probabilistic material data give a good prospective on results rather than a single deterministic simulation results. The next part of research is to implement the probabilistic material properties in engineering designs. The main aim of structural design is to obtain optimal solutions. In any case, in a deterministic optimization problem even though the structures are cost effective, it becomes highly unreliable if the uncertainty that may be associated with the system (material properties, loading etc.) is not represented or considered in the solution process. Reliable and optimal solution can be obtained by performing reliability optimization along with the deterministic optimization, which is RBDO. In RBDO problem formulation, in addition to structural performance constraints, reliability constraints are also considered. This part of research starts with introduction to reliability analysis such as first order reliability analysis, second order reliability analysis followed by simulation technique that are performed to obtain probability of failure and reliability of structures. Next, decoupled RBDO procedure is proposed with a new reliability analysis formulation with sensitivity analysis, which is performed to remove the highly reliable constraints in the RBDO, thereby reducing the computational time and function evaluations. Followed by implementation of the reliability analysis concepts and RBDO in finite element 2D truss problems and a planar beam problem are presented and discussed.
ContributorsDeivanayagam, Arumugam (Author) / Rajan, Subramaniam D. (Thesis advisor) / Mobasher, Barzin (Committee member) / Neithalath, Narayanan (Committee member) / Arizona State University (Publisher)
Created2012
Description
Concrete design has recently seen a shift in focus from prescriptive specifications to performance based specifications with increasing demands for sustainable products. Fiber reinforced composites (FRC) provides unique properties to a material that is very weak under tensile loads. The addition of fibers to a concrete mix provides additional ductility and reduces the propagation of cracks in the concrete structure. It is the fibers that bridge the crack and dissipate the incurred strain energy in the form of a fiber-pullout mechanism. The addition of fibers plays an important role in tunnel lining systems and in reducing shrinkage cracking in high performance concretes. The interest in most design situations is the load where cracking first takes place. Typically the post crack response will exhibit either a load bearing increase as deflection continues, or a load bearing decrease as deflection continues. These behaviors are referred to as strain hardening and strain softening respectively. A strain softening or hardening response is used to model the behavior of different types of fiber reinforced concrete and simulate the experimental flexural response. Closed form equations for moment-curvature response of rectangular beams under four and three point loading in conjunction with crack localization rules are utilized. As a result, the stress distribution that considers a shifting neutral axis can be simulated which provides a more accurate representation of the residual strength of the fiber cement composites. The use of typical residual strength parameters by standards organizations ASTM, JCI and RILEM are examined to be incorrect in their linear elastic assumption of FRC behavior. Finite element models were implemented to study the effects and simulate the load defection response of fiber reinforced shotcrete round discrete panels (RDP's) tested in accordance with ASTM C-1550. The back-calculated material properties from the flexural tests were used as a basis for the FEM material models. Further development of FEM beams were also used to provide additional comparisons in residual strengths of early age samples. A correlation between the RDP and flexural beam test was generated based a relationship between normalized toughness with respect to the newly generated crack surfaces. A set of design equations are proposed using a residual strength correction factor generated by the model and produce the design moment based on specified concrete slab geometry.
ContributorsBarsby, Christopher (Author) / Mobasher, Barzin (Thesis advisor) / Rajan, Subramaniam D. (Committee member) / Neithalath, Narayanan (Committee member) / Arizona State University (Publisher)
Created2011
Description
Profound alterations to instruments that take place over short periods of time are fascinating, and the changes undergone by the guitar during the late eighteenth century make for an intriguing transition in the instrument's history. The guitar that existed before 1750 is most commonly referred to as the 'Baroque guitar' and is vastly different from the guitar of today. It was considerably smaller than the guitars that followed, pitched higher, and used primarily for accompaniment through chord strumming. From roughly 1750 to 1800 the guitar underwent a transformation that eventually led to the design and performance practices that have continued through to this day; larger, with lower-pitched courses (and sometimes single stringing), and used increasingly more in punteado (plucked) style. By defining the instrument as it existed prior to 1750, and the changes that it underwent after 1750, we can ensure that the instrument discussed is the one that has directly led to the instrument we use today. Because instrument design and performance practice inevitably influence each other, a thorough examination of ornamentation practices from 1750-1800 can lead to a greater understanding of the instrument as it changed, and the instrument it eventually turned into. Since the early nineteenth century was one of the more productive time periods for the guitar, having a better understanding of the ornamentation performance practices that preceded it may provide insight to how the players and composers of this fertile time (Sor, Aguado, Giuliani, etc.) approached their instrument. Although there was not much music printed or copied for guitar during the latter half of the eighteenth century, a substantial number of guitars were built, along with instruction manuals featuring the guitar. Instruction manuals were examined, along with works for solo guitar and guitar in ensemble with other instruments, to explore ornamentation practices from 1750-1800. Through examination of the guitar instruction manuals of the late eighteenth century, an increased understanding is gained regarding the techniques that eventually became cornerstones of nineteenth-century guitar performance practice.
ContributorsCopeland, Jeffrey S. (Jeffrey Scott), 1953- (Author) / Koonce, Frank (Thesis advisor) / Aspnes, Lynne (Committee member) / Feisst, Sabine (Committee member) / Jiang, Danwen (Committee member) / Landschoot, Thomas (Committee member) / Arizona State University (Publisher)
Created2012
Description
The solo repertoire from the Light Music Era serves as an important link between the Classical and Jazz soloist traditions. These characteristics are best highlighted through an analysis of three solo transcriptions: Felix Arndt's Nola as performed by Al Gallodoro, Rudy Wiedoeft's Valse Vanité, as performed by Freddy Gardener, and Jimmy Dorsey's Oodles of Noodles, as performed by Al Gallodoro. The transcriptions, done by the author, are taken from primary source recordings, and the ensuing analysis serves to show the saxophone soloists of the Light Music Era as an amalgamation of classical and jazz saxophone. Many of the works performed during the Light Music Era are extant only in recorded form. Even so, these performances possess great historical significance within the context of the state of the saxophone as an important solo instrument in the wider musical landscape. The saxophone solos from the Light Music Era distinguish themselves through the use of formal development and embellishment of standard "song forms" (such as ABA, and AABA), and the use of improvisational techniques that are common to early Jazz; however, the analysis shows that the improvisational techniques were distinctly different than a Jazz solo improvisation in nature. Although it has many characteristics in common with both "Classical Music" (this is used as a generic term to refer to the music of the Western European common practice period that is not Pop music or Jazz) and Jazz, the original research shows that the saxophone solo music from the Light Music Era is a distinctly original genre due to the amalgamation of seemingly disparate elements.
ContributorsPuccio, Dan (Author) / Mcallister, Timothy P (Thesis advisor) / Feisst, Sabine (Committee member) / Kocour, Michael (Committee member) / Pilafian, J. Samuel (Committee member) / Spring, Robert (Committee member) / Arizona State University (Publisher)
Created2012
Description
Ultra-concealable multi-threat body armor used by law-enforcement is a multi-purpose armor that protects against attacks from knife, spikes, and small caliber rounds. The design of this type of armor involves fiber-resin composite materials that are flexible, light, are not unduly affected by environmental conditions, and perform as required. The National Institute of Justice (NIJ) characterizes this type of armor as low-level protection armor. NIJ also specifies the geometry of the knife and spike as well as the strike energy levels required for this level of protection. The biggest challenges are to design a thin, lightweight and ultra-concealable armor that can be worn under street clothes. In this study, several fundamental tasks involved in the design of such armor are addressed. First, the roles of design of experiments and regression analysis in experimental testing and finite element analysis are presented. Second, off-the-shelf materials available from international material manufacturers are characterized via laboratory experiments. Third, the calibration process required for a constitutive model is explained through the use of experimental data and computer software. Various material models in LS-DYNA for use in the finite element model are discussed. Numerical results are generated via finite element simulations and are compared against experimental data thus establishing the foundation for optimizing the design.
ContributorsVokshi, Erblina (Author) / Rajan, Subramaniam D. (Thesis advisor) / Neithalath, Narayanan (Committee member) / Mobasher, Barzin (Committee member) / Arizona State University (Publisher)
Created2012
Description
The current method of measuring thermal conductivity requires flat plates. For most common civil engineering materials, creating or extracting such samples is difficult. A prototype thermal conductivity experiment had been developed at Arizona State University (ASU) to test cylindrical specimens but proved difficult for repeated testing. In this study, enhancements to both testing methods were made. Additionally, test results of cylindrical testing were correlated with the results from identical materials tested by the Guarded Hot&ndashPlate; method, which uses flat plate specimens. In validating the enhancements made to the Guarded Hot&ndashPlate; and Cylindrical Specimen methods, 23 tests were ran on five different materials. The percent difference shown for the Guarded Hot&ndashPlate; method was less than 1%. This gives strong evidence that the enhanced Guarded Hot-Plate apparatus in itself is now more accurate for measuring thermal conductivity. The correlation between the thermal conductivity values of the Guarded Hot&ndashPlate; to those of the enhanced Cylindrical Specimen method was excellent. The conventional concrete mixture, due to much higher thermal conductivity values compared to the other mixtures, yielded a P&ndashvalue; of 0.600 which provided confidence in the performance of the enhanced Cylindrical Specimen Apparatus. Several recommendations were made for the future implementation of both test methods. The work in this study fulfills the research community and industry desire for a more streamlined, cost effective, and inexpensive means to determine the thermal conductivity of various civil engineering materials.
ContributorsMorris, Derek (Author) / Kaloush, Kamil (Thesis advisor) / Mobasher, Barzin (Committee member) / Phelan, Patrick E (Committee member) / Arizona State University (Publisher)
Created2011
Description
Since the early 1990's, researchers have been looking at intersections between education and music. After a highly popular study correlating listening to Mozart to temporary increases in spatial reasoning, many other researchers tried to find a link between different musical genres and learning outcomes. Using three musical treatments (Pop, classical, silence), this study had subjects (N=34) complete a reading-based task whereupon they were tested on their comprehension. Using a suite of sensors, data was collected to analyze the participants' emotions and affect while they read from an educational psychology textbook. The present study has two major focuses: They detail whether (1) changes in musical condition affect learning outcomes and (2) whether changes in musical condition affect emotional outcomes. The popular conception that listening to classical music makes you smarter was proven false long ago, but there may actually be some merit to using music to assist one in studying. While there were no significant changes in test scores depending on musical condition; frustration levels were significantly lower for those who listened to classical instead of pop music.
ContributorsPaley, Benjamin Henry (Author) / Atkinson, Robert (Thesis director) / Feisst, Sabine (Committee member) / Barrett, The Honors College (Contributor) / School of Music (Contributor) / T. Denny Sanford School of Social and Family Dynamics (Contributor)
Created2015-05
Description
Calcium hydroxide carbonation processes were studied to investigate the potential for abiotic soil improvement. Different mixtures of common soil constituents such as sand, clay, and granite were mixed with a calcium hydroxide slurry and carbonated at approximately 860 psi. While the carbonation was successful and calcite formation was strong on sample exteriors, a 4 mm passivating boundary layer effect was observed, impeding the carbonation process at the center. XRD analysis was used to characterize the extent of carbonation, indicating extremely poor carbonation and therefore CO2 penetration inside the visible boundary. The depth of the passivating layer was found to be independent of both time and choice of aggregate. Less than adequate strength was developed in carbonated trials due to formation of small, weakly-connected crystals, shown with SEM analysis. Additional research, especially in situ analysis with thermogravimetric analysis would be useful to determine the causation of poor carbonation performance. This technology has great potential to substitute for certain Portland cement applications if these issues can be addressed.
ContributorsHermens, Stephen Edward (Author) / Bearat, Hamdallah (Thesis director) / Dai, Lenore (Committee member) / Mobasher, Barzin (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor)
Created2015-05
Description
Biofeedback music is the integration of physiological signals with audible sound for aesthetic considerations, which an individual’s mental status corresponds to musical output. This project looks into how sounds can be drawn from the meditative and attentive states of the brain using the MindWave Mobile EEG biosensor from NeuroSky. With the MindWave and an Arduino microcontroller processor, sonic output is attained by inputting the data collected by the MindWave, and in real time, outputting code that deciphers it into user constructed sound output. The input is scaled from values 0 to 100, measuring the ‘attentive’ state of the mind by observing alpha waves, and distributing this information to the microcontroller. The output of sound comes from sourcing this into the Musical Instrument Shield and varying the musical tonality with different chords and delay of the notes. The manipulation of alpha states highlights the control or lack thereof for the performer and touches on the question of how much control over the output there really is, much like the experimentalist Alvin Lucier displayed with his concepts in brainwave music.
ContributorsQuach, Andrew Duc (Author) / Helms Tillery, Stephen (Thesis director) / Feisst, Sabine (Committee member) / Barrett, The Honors College (Contributor) / Herberger Institute for Design and the Arts (Contributor) / Harrington Bioengineering Program (Contributor)
Created2014-05
Description
Labyrinths is my Capstone/Honors Creative Project, blending my proclivity for music composition and the inspiring stories of Jorge Luis Borges. Originally, the project was outlined as a collection of five to eight songs named for and based on stories in Borges' collection Labyrinths, to be written, recorded, and performed by me. Over time other aspects were included, making me a director of a large-scale creative project which now included three other musicians and two artists. In this paper, I give a brief overview of Borges' life and the context surrounding his collection Labyrinths, an in-depth description of the project as a whole, liner notes for each song, credits, and three appendices. The liner notes are broken into four sections: a summary of the story, an analysis of the story and my interpretation of it (including my musical ideas for the resulting song), an effects list, and performance notes which include the text I read from each story in the performance and recordings. The first appendix is a collection of the sheet music scores for each song and the text document I used for the performance readings. The second appendix shows the art I was given permission to use, and how I modified them for my thesis. The third appendix contains my primary sources, secondary sources/suggested readings, and suggested websites and videos. Attached are the recordings of each song I made in Logic Pro 9, a video of the live performance, and an unedited audio recording of the same performance.
ContributorsVidean, Matthew Cutter (Author) / Stauffer, Sandra (Thesis director) / Feisst, Sabine (Committee member) / Downey, Ryan (Committee member) / Barrett, The Honors College (Contributor) / Herberger Institute for Design and the Arts (Contributor) / School of International Letters and Cultures (Contributor)
Created2014-12