Study reveals composite combination evaluations for boron binder reinforcements for unidirectly reinforced boron/epoxy, glass binder reinforcements for unidirectionally reinforced boron/epoxy, and glass binder reinforcements for unidrectionally reinforced glass/epoxy

Dow, N. F.

Rosen, B. W.

English

NASA Technical Reports Server

August 1970
	 Brief 70-10205 
NASA TECH BRIEF H 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage commercial 
application. Tech Briefs are available on a subscription basis from the Clearinghouse for Federal Scientific and Technical 
Information, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Division, NASA, Code UT, Washington, D.C. 20546. 
Design and Evaluation of Three-Phase Fibrous Composite Structures 
An important objective in the study of the mechanics 
of composite structures is the determination of the 
relationship between the strength of a fibrous com-
posite and the mechanical properties and geometry 
of its constituents. A relationship of this type can be 
utilized in the definition of desirable improvements 
in constituent properties, as well as in the evaluation 
of the structural potential of various composite 
materials. 
In this study three possible composite combinations 
were evaluated: (1) boron binder reinforcement for 
unidirectionally reinforced boron/epoxy; (2) glass 
binder reinforcement for unidirectionally reinforced 
glass/epoxy; and (3) glass binder reinforcement for 
unidirectionally reinforced boron/epoxy. In the first 
two cases the total amount of reinforcing material 
in the composite was held constant, while in the last 
case the volume percentage of filament was held 
constant. 
Assuming nominal constituent properties, the 
potential magnitude of the increase in compressive 
strength was calculated. For properties similar to 
those of the boron/epoxy composites, a conversion 
of a small percentage of the axial filaments into trans-
verse filaments should raise the compressive strength 
from 392 ksi to 550 ksi; substantial gains were also 
expected for the glass plus boron/epoxy composite. 
Because of the gains found in the calculations for 
the unidirectional boron/epoxy composites, a series 
of these specimens, having various percentages of
chopped-glass filaments added to the binder, were 
fabricated. The test results, despite the large scatter, 
appeared to indicate a strengthening. The gross effects 
produced by the small amounts of binder reinforce-
ment demonstrate the critical role of the binder in 
the composite for the development of high compres-
sive stresses. This criticality is substantially greater 
for boron than for glass reinforcement. 
Note: 
The following documentation may be obtained 
from:
Clearinghouse for Federal Scientific 
and Technical Information 
Springfield, Virginia 22151 
Single document price $3.00 
(or microfiche $0.65) 
Reference: 
NA SA-CR-665 18 (N68-13962), Design 
Criteria and Concepts for Fibrous Com-
posite Structures 
Patent status: 
Inquiries about obtaining rights for the commercial 
use of this invention may be made to NASA, Code 
GP, Washington, D.C. 20546. 
Source: B. W. Rosen and N. F. Dow of 
General Electric Company 
under contract ti' 
NASA HeadquarteiJ' 
(HQN- 10267) 
Category 04 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned.rights.
https://ntrs.nasa.gov/search.jsp?R=19700000197 2020-03-17T00:13:22+00:00Z


Design and evaluation of three-phase fibrous composite structures

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server