Digital Commons Network^™

Finite Element Studies In Metal Cutting, Suhail Ahmed

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

AdvantEdge is a finite element software package that integrates advanced dynamics, thermo-mechanically coupled finite element numerics and material modelling appropriate for machining processes. AdvantEdge allows users to specify the workpiece material, tool geometry and cutting conditions. It then provides accurate estimates of thermo-mechanical properties of machining processes such as cutting forces, chip morphology, machined surface residual stresses and temperature behavior of the tool and the workpiece. We will use AdvantEclge to investigate two areas of interest in metal cutting: process clamping via crushing of workpiece material and drilling of metal stacks.

Test Suite For Multiobjective Optimization And Results Using Normal Boundary Intersection (Nbi) In Design Explorer, Siva Kumar Natarajan

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Several methods have been developed to solve multiobjective optimization problems (MOP's). One of these, Normal Boundary Intersection (NBI), is a method developed by John Dennis and Indraneel Das. NBI is used at The Boeing Company as a tool to solve MOP's. This report presents a test suite of MOP's that I developed for Boeing during me internship in summer 2003.

The problems in the test suite were chosen to represent the different types of multiobjective optimization problems that could arise in practice and the complexities involved in solving them. These problems range from those that have nice convex Pareto surfaces …

Computer Simulation And Homogenization In Heating Design Optimization, Daniel K. Balls

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The ability to ensure uniformity of temperature within a given finite physical region is an essential element in the success of many scientific processes, especially those that involve extreme fluctuation in temperature. Such a process is performed in an instrument called the LightTyper developed by Idaho Technology, Inc. of Salt Lake City Utah. This paper details the development and results of a scheme intended to obtain a heating design that ensures a high degree of temperature uniformity within the Idaho Technology instrument. Due to the experiments performed during this project, we were able to answer many questions that concerned finding …

Identification Of Optimal Conditions For Dry Drilling (Analytical Approach To Prediction Of The Occurrence Of Bue), Prasad Gali

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lubrication is used during the drilling of aluminum to counter the formation of a built-up-edge (BUE), among other reasons. The elimination of the use of lubricants in drilling of aluminum is important because of the associated high costs of cleaning and disassembly involved in lubrication. The optimal conditions sought in this work include the elimination of the use of lubricants along with the possible attainment of a high material removal rate, which could help in reduction of cost and increase productivity at the same time. BUE has been found to be almost always present in the process of metal cutting …

Bootstrap Unit Root Tests For Heavy-Tailed Observations, Andrejus Parfionovas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We explore the application of the bootstrap unit root test to time series with heavy-tailed errors. The size and power of the tests are estimated for two different autoregressive models (AR(1)) using computer simulated data. Real-data examples are also presented. Two different bootstrap methods and the subsampling approach are compared. Conclusions on the optimal bootstrap parameters, the range of applicability, and the performance of the tests are made.

Predicting Mountain Pine Beetle Development With The Extended Von Foerster Model, Jeffrey Tullis Leek

Undergraduate Honors Capstone Projects

The mountain pine beetle (Dendroctonus ponderosae Hopkins) represents a significant threat to ponderosa pine and lodgepole pine stands in the western United States, and has the potential to threaten commercially valuable jack pine in both the United States and Canada. The success of the mountain pine beetle is based on synchronization of developmental events to time cold-hardened life stages for extreme winter temperatures and to facilitate mass attack and overwhelm the defenses of the host. This paper presents a solution methodology for an extended McKendrick - von Foerster model for the development of the mountain pine beetle in varying …