High temperature pressure sensing is desirable for a broad range of applications related to re-entry of space vehicles and control of
combustion processes; however, limited materials can sustain temperatures above 1000C while under time-varying pressure. A sapphire based
optical pressure transducer has been proposed for measuring pressure at temperatures approaching 1600C. Manufacturing such sensors has
focused on picosecond laser machining. Current research has produced models which can predict ablation depth for longer (ns) pulses and
shorter (fs) pulses but there is an underwhelming amount of research focusing on predicting and understanding the mechanics of picosecond
pulses. This is partially because of transitions in the mode of ablation processes associated with photothermal versus photochemical
behavior. We put forth a general model for laser ablation using Maxwell's equations and a sharp interface equation and compare different
constitutive laws which couple the two equations together. The proposed modeling results are compared to laser machining experimental data on
sapphire from the literature to illustrate key material parameter uncertainty and sensitivity to the laser machining process. Bayesian
uncertainty quantification is used to help validate the approximations within the constitutive equations. / A Thesis submitted to the Department of Mechanical Engineering in partial fulfillment of the requirements
for the degree of Master of Science. / Summer Semester 2016. / July 8, 2016. / dielectrics, laser ablation, picosecond, sapphire, uncetainty quantificion / Includes bibliographical references. / William S. Oates, Professor Directing Thesis; Shangchao Lin, Committee Member; Wei Guo, Committee
Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_605033 |
| Contributors | Woerner, Peter Christopher (author), Oates, William (professor directing thesis), Lin, Shangchao (committee member), Guo, Wei (committee member), Florida State University (degree granting institution), College of Engineering (degree granting college), Department of Mechanical Engineering (degree granting departmentdgg) |
| Publisher | Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text, master thesis |
| Format | 1 online resource (52 pages), computer, application/pdf |
Page generated in 0.0024 seconds