Degree Type


Date of Award


Degree Name

Master of Science


Materials Science and Engineering

First Advisor

Dale E. Chimenti

Second Advisor

R. Bruce Thompson


Over the past quarter century, substantial advances have been made in the aerospace applications of composites. The designs of modern aircraft, particularly military fighter aircraft, demand high-strength, high-stiffness, low-weight materials. While multiphase composite materials of various kinds have been used for centuries, the development in the last 40 years of high-stiffness continuous fibers, either of graphite or glass, has changed the picture for aerospace materials. Coupled with reliable interfacial chemistry at the fiber-matrix interface and advanced epoxies and thermoplastics, composite laminates began appearing in high-performance aircraft around 1970. The boron-epoxy speed brake on the McDonnell-Douglas F-15A was one of the first such applications. With better control of the graphitizing process, high-stiffness, micron-sized carbon fibers began making their appearance composite form. These fibrous composite laminates have fulfilled the demand for ever stiffer and lighter materials, but not without some disadvantages. Fiber-epoxy laminates have a well-known sensitivity to impact damage and degradation due to environmental factors, such as ultraviolet light and moisture. Additionally, the cost of producing and maintaining fiber-epoxy laminates is very high. In order for combat aircraft to meet their performance objectives, these limitations must be accommodated. Military transport and commercial aircraft, however, are much more cost-sensitive and must be economically maintainable.



Digital Repository @ Iowa State University,

Copyright Owner

Arnold H. Kettenacker



Date Available


File Format


File Size

104 pages

Included in

Metallurgy Commons