Laser
EMBEDDED SENSORS IN LAYERED MANUFACTURING
A DISSERTATION SUBMITTED TO THE DEPARTMENT OF MECHANICAL ENGINEERING AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
Xiaochun Li June 2001
© Copyright by Xiaochun Li 2001
All Rights Reserved
ii
I certify that I have read this dissertation and that in my opinion it is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy.
Fritz Prinz (Principal Adviser)
I certify that I have read this dissertation and that in my opinion it is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy.
Thomas W. Kenny
I certify that I have read this dissertation and that in my opinion it is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy
Drew V. Nelson
Approved for the University Committee on Graduate Studies:
iii
Abstract
Layered Manufacturing can be applied to build "smart" parts with sensors, integrated circuits, and actuators placed within the component. Embedded sensors can be used to gain data for validating or improving designs during the prototype stage or to obtain information on the performance and structural integrity of components in service. Techniques for embedding fiber optic sensors in metals, polymers, and ceramics have been investigated. Embedding optical fibers into metals is especially challenging because engineering alloys tend to exhibit high melting temperatures. In the present research an embedding sequence was developed capable of embedding fiber sensors into parts made of metal alloys with high melting temperatures. Fiber Bragg Grating (FBG) sensors were selected as the most promising sensor candidate. The embedded FBG sensors were characterized for temperature and strain measurements. The embedded FBG sensors in nickel and stainless steel provided high sensitivity, good accuracy, and
A DISSERTATION SUBMITTED TO THE DEPARTMENT OF MECHANICAL ENGINEERING AND THE COMMITTEE ON GRADUATE STUDIES OF STANFORD UNIVERSITY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
Xiaochun Li June 2001
© Copyright by Xiaochun Li 2001
All Rights Reserved
ii
I certify that I have read this dissertation and that in my opinion it is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy.
Fritz Prinz (Principal Adviser)
I certify that I have read this dissertation and that in my opinion it is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy.
Thomas W. Kenny
I certify that I have read this dissertation and that in my opinion it is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy
Drew V. Nelson
Approved for the University Committee on Graduate Studies:
iii
Abstract
Layered Manufacturing can be applied to build "smart" parts with sensors, integrated circuits, and actuators placed within the component. Embedded sensors can be used to gain data for validating or improving designs during the prototype stage or to obtain information on the performance and structural integrity of components in service. Techniques for embedding fiber optic sensors in metals, polymers, and ceramics have been investigated. Embedding optical fibers into metals is especially challenging because engineering alloys tend to exhibit high melting temperatures. In the present research an embedding sequence was developed capable of embedding fiber sensors into parts made of metal alloys with high melting temperatures. Fiber Bragg Grating (FBG) sensors were selected as the most promising sensor candidate. The embedded FBG sensors were characterized for temperature and strain measurements. The embedded FBG sensors in nickel and stainless steel provided high sensitivity, good accuracy, and