Engineering Commons^™

Predicting The Seismic Behavior Of The Dywidag Ductile Connector (Ddc) Precast Concrete System, Elizabeth Mary Kenyon

Master's Theses

Structural engineering is heavily dependent on the use of computers. When creating a building model using structural analysis software, it is required that the designer have an understanding of the system behavior and the modeling program capabilities.

Some engineers in the Southern California region are taking steps towards incorporating the Dywidag ductile connector (DDC) and super hybrid systems into building practice due to the advantages found in these systems’ construction methods and seismic performance.

As the DDC and super hybrid systems reach industry, the design engineer will need to model these systems using structural analysis programs. This report describes two …

Parametric Optimization Design System For A Fluid Domain Assembly, Matthew Jackson Fisher

Theses and Dissertations

Automated solid modeling, integrated with computational fluid dynamics (CFD) and optimization of a 3D jet turbine engine has never been accomplished. This is due mainly to the computational power required, and the lack of associative parametric modeling tools and techniques necessary to adjust and optimize the design. As an example, the fluid domain of a simple household fan with three blades may contain 500,000 elements per blade passage. Therefore, a complete turbine engine that includes many stages, with sets of thirty or more blades each, will have hundreds of millions of elements. The fluid domains associated with each blade creates …

Replication Of Metal-Based Microscale Structures By Compression Molding: A Combined Experimental And Finite Element Analysis Study, Jing Jiang

LSU Doctoral Dissertations

Fabrication of microscale Ta mold inserts by micro-electrical-discharge-machining (ìEDM) is reported. Morphology, chemistry, and structure of the near-surface region of as-machined Ta blanks have been characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. A TaC surface layer forms on as-machined Ta surfaces. This altered surface layer was removed by electro-chemical-polishing. Further modification of Ta insert surfaces was accomplished by deposition of a conformal Ti-containing hydrogenated carbon coating. We demonstrate successful replication of high-aspect-ratio microscale structures (HARMS) in Al and Cu by compression molding with such surface-engineered Ta mold inserts. In addition, a hybrid microfabrication technique, combining …