Engineering Commons^™

Analyzing The Supply Chain Operation Of A Fast-Food Restaurant Using Simulation Modeling And Developing A Cost Estimation Optimization Model In The Disruption Period, Amit Kumar Saha

Open Access Theses & Dissertations

Supply chain operation performance is a much-discussed topic over the last decade which will lead to optimizing the resources required to provide the necessary level of customer service to a specific segment and improve customer service through increased product availability and reduced order cycle time. During disruption in supply chain, performance parameter changes, and the overall supply chain cost at each stage increases. External factors such as labor shortages, delayed and costly supplies, and decreased demand also contribute to this cost. This thesis work presents a research-focused analysis of a small pizza shop, under circumstances that include the loss of …

Thermal/Mechanical Analysis And Development Of A 2000 Lbf Liquid Oxygen/Liquid Methane Rocket Engine, Marissa Garcia

Open Access Theses & Dissertations

The Center for Space Exploration and Technology Research (cSETR) is developing three rocket engines: a 5 lbf reaction control engine, a 500 lbf engine, and a 2000 lbf engine. All these engines utilize a liquid oxygen and liquid methane propellant combination. The reason methane was selected for the fuel is because methane is easy to store, is self-pressurizing, and readily available. There is also the possibility of creating methane on planets such as Mars through an electrolysis process on the ice water found on Mars.

The 2000 lbf engine, or the CROME-X, is a modular, steady-state pintle injector engine. It …

Utilization Of Digital Image Correlation Technique In Asphalt Testing, Alejandra Escajeda

Open Access Theses & Dissertations

Over 90% of the roads in the United States are paved with hot mix asphalt (HMA). These asphalt pavements include many mix types, such as permeable friction course (PFC), stone mastic asphalt (SMA) and conventional dense graded mixes. The performance of the HMA is an important factor in pavement design programs used by many departments of transportation. The type of HMA selected not only influences the performance of the pavement structure, but also the pavement's life cycle cost. The performance life of an HMA mix is to be studied further with experimental data in order to contribute and expand on …

Sensitivity Analysis Of The Johnson-Cook Plasticity Model For Hypervelocity Impacts: A Hydro-Code Study, Carlos David Castellanos

Open Access Theses & Dissertations

Computer simulations have been in use for decades in the modeling of hypervelocity impacts and general large deformation problems. Several computer codes have been developed to simulate this type of problems under a variety of geometric configurations and for any number of materials. These codes make use of several constitutive material models to simulate the response of the material under a variety of thermo-mechanical conditions. The Johnson-Cook constitutive model is widely used in the simulation hypervelocity impacts for the simulation of crater formation and even perforation of target structures. This thesis presents the results of a sensitivity study of this …