Doctoral Dissertations


John M. Barr


"Composites with excellent optical clarity have been fabricated by matching the refractive index of the glass fiber reinforcement to that of the polymer matrix. Refractive index mismatch, resulting from temperature changes, leads to degradation of optical clarity in fiber composites due to light impinging upon the fiber/matrix interface at oblique angles of incidence. The plane parallel surfaces of glass ribbon reinforcement minimize incidence at oblique angles, thereby reducing the sensitivity to refractive index mismatch. Optical data show that the use of ribbons in place of fibers increases the temperature range over which these composites retain good optical clarity by more than five times.

A Monte Carlo type simulation of optical transmission of fiber reinforced composites has been developed. Temperature dependent optical transmission of glass fiber and ribbon reinforced composites was measured using a He/Ne laser and a detection assembly with an acceptance angle of 0.15°. Good agreement was observed between the measured transmission data and the calculations from the computer model. The computer model was used to predict achievable optical transmission in hypothetical fiber and ribbon composites with varying dn/dT and glass content. Results indicate that ribbon reinforced composites have the potential for nearly temperature independent optical clarity.

Flexural strength of glass fiber and ribbon reinforced composites was calculated from 3-point bend data on specimens with a neat PMMA core and composite veneer on the surfaces. Veneer strength was 40 to 50% higher than that of neat PMMA. A hypothetical quasi-isotropic veneered composite was designed using lamination theory. For equivalent load bearing capacity beams, the mass of the composite is 16 and 70% less than neat PMMA and fused silica, respectively"--Abstract, page iv.


Day, D. E.

Committee Member(s)

Stoffer, James O.
Moore, Robert E., 1930-2003
Huebner, Wayne
Carroll, Douglas R.


Materials Science and Engineering

Degree Name

Ph. D. in Ceramic Engineering


The author greatly appreciates the support from the National Defense Science and Engineering Graduate Fellowship program and McDonnell Aircraft Company that made this graduate program possible.


University of Missouri--Rolla

Publication Date

Spring 1997

Journal article titles appearing in thesis/dissertation

  • Optical properties of BK10 glass fiber and ribbon reinforced poly(methyl methacrylate) composites
  • Modeling of the temperature dependent transmission of glass fiber and ribbon reinforced poly(methyl methacrylate) composites


xiv, 135 pages

Note about bibliography

Includes bibliographical references.


© 1997 John Matthew Barr, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type




Thesis Number

T 7301

Print OCLC #


Link to Catalog Record

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