Composite bulkhead is produced by a fabrication concept utilizing vacuum and/or autoclave pressure to hold preformed welded sandwich elements in place during bonding and aging

Orr, J.

English

NASA Technical Reports Server

December 1966	 Brief 66-10582 
NASA TECH BRIEF 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Composite Bulkhead Fabrication Development 
The primary objective is to design, fabricate, and 
evaluate by empirical analysis a composite bulkhead 
produced by a fabrication concept utilizing vacuum 
and/or autoclave pressure to hold preformed welded 
sandwich elements in place during bonding and aging. 
Included is a minimum of design for a 105-inch 
diameter composite bulkhead for the purpose of 
approaching space flight type hardware upon which 
the principal objective (evaluation of dimensional 
behavior) can be accomplished. The bulkhead is de-
signed and fabricated from 2219 aluminum alloy 
skins chem-milled on one side only to a 0.060 inch 
thickness except in the weld land areas where they 
remain a nominal 0.090 inch thickness. The outer 
skin is assembled by welding eight stretch-formed 
and chemically-milled gore segments into a welded 
skin assembly slightly smaller than the concave bond-
ing and aging tool. 
Final form is fixed in the approved concave form-
ing and aging tool by age forming the outer skin 
under vacuum and 60 psig autoclave pressure at 
325°F for 16 hours. A honeycomb core of one-inch 
thickness heat resistant phenolic is bonded to the 
outer skin with adhesive film cured at 325 1 F for one 
hour at 30 psig autoclave pressure. The inner skin is
final formed against the core at 60 psig autoclave 
pressure for 16 hours at 325°F and then bonded to 
the core with adhesive for a one-hour cure period. 
Additional cure and aging time of 6 3/4 hours is 
applied to the inner skin and assembly, to approach 
the desired minimum inner skin aging time of 24 
hours, to provide maximum corrosion resistance to 
the alloy. Measurements of the welded skin assem-
blies are taken in the free state, under vacuum, after 
aging, and after bonding into an assembly, and are 
compared with the inside contour of the concave 
bonding and aging tool as the dimensional base. 
Note: 
Inquiries concerning this development may be di-
rected to:
Technology Utilization Officer 
Marshall Space Flight Center 
Huntsville, Alabama 35812 
Reference: B66-10582 
Patent status: 
No patent action is contemplated by NASA. 
Source: James Orr 
(M-FS- 1264) 
Category 05 
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=19660000580 2020-03-11T17:45:31+00:00Z


Composite bulkhead fabrication development

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