Engineering Science and Materials Commons^™

A Characteristics Finite Element Algorithm For Computational Open Channel Flow Analysis, Zachariah Chambers

Doctoral Dissertations

For the reliable determination of open channel flows, a minimally dissipative flux jacobian decomposition finite element algorithm is developed for the one- and two-dimensional inviscid open channel flow equation systems. The modifed form of the parent kinetic flux divergence is biased by the characteristic speeds, i.e. eigenvalues of the kinetic flux divergence jacobian, to induce along all wavelike propogation directions a dissipation level proportional to the propogation speeds of the solution to the hyperbolic problem statement.

The analysis rigorously investigates the inviscid open channel equation system via non-linear, wave-like solutions and reveals linear dependency issues for the momentum equations in …

Finite Element Analysis Of A Composite Cylindrical Shell With A Cutout Under A Fatigue Load, Joshua T. Boatwright

Theses and Dissertations

A higher-order shell theory is used to analyze compressive and tensile loads on a graphite/epoxy laminated cylinder containing a square cutout. The Hashin failure criterion is used to determine failure in the fiber, matrix, or lamination. Once failure occurs, the appropriate stiffness terms are reduced. This failure causes a redistribution of stress, leading to further failure. In order to account for the loss of residual strength due to cyclic loading, the stiffness matrix is further reduced at each new increment of load or displacement. The objective is not to determine the S-N curve for the material, but rather to determine …

Mechanics Of A Functionally-Graded Titanium Matrix Composite, G. Brandt Miller

Theses and Dissertations

Functionally-graded Titanium Matrix Composites, (F/G TMCs) combine the ideal properties of titanium matrix composites with the more practical machining qualities of monolithic (unreinforced) alloy. This material shows great promise in application to aerospace structural components - even in parts whose design requirements have defied the use of composite materials in the past. Successful implementation of such a material would lead to enhanced aircraft performance. However, the basic properties of a functionally-graded titanium matrix composite need to be investigated. The composite/alloy transition region, or joint area, may be less strong than its constituents and therefore determine the overall performance of the …

Evaluation Of Moisture Barriers For Fire Fighting Turnout Gear Assessment Of Product Failure And Test Method Development Predicting Failure Modes, Chastity Danielle Newsome

Theses and Dissertations--Retailing and Tourism Management

The purpose of this study was to investigate the failures seen in the moisture barrier of fire fighting turnout gear. Moisture barriers taken from garments in field were evaluated to establish a baseline for comparison. Moisture barriers were exposed as part of a three-piece ensemble and as a single layer moisture barrier to instrumental light exposure in a Carbon Arc Fade-ometer and natural sunlight exposure according to AATCC and ASTM test methods. After exposure, moisture barriers were visually examined using stereo and compound microscopes. A performance measurement was conducted on the exposed moisture barriers using a modified NFPA Hydrostatic Water …