TM 1-1500-204-23-11
different than similar joints in metal structure. Local
regions of high stress concentrations occur which
require special attention. Composite joints are also
more sensitive to edge distance and hole spacing,
Failure to properly cure adhesive in accor-
and have different considerations in fastener selec-
dance with the speciied cure cycle will result in
tion and galvanic corrosion than similar metal joints.
reduced repair strength may not be detectable
Mechanically fastened joints are often preferred over
by visual or nondestructive inspection. This
bonded joints, since mechanically fastened joints can
may result in loss of structural integrity.
be disassembled and the structural integrity can be
more easily guaranteed. Three commonly used bolted
(15) Remove any residual adhesive on the adhe-
repair joints are shown in igure 7-18. For all compos-
sive comb by wiping with clean, dry wiping
ite bolted joints, consult the system speciic technical
cloth. Apply solvent to another clean, dry
manual or engineering for additional guidance. Engi-
wiping cloth. Wipe the adhesive comb clean.
neering guidance for bolted joints can also be found
Allow to air dry for 30 minutes. Ensure adhe-
in Chapter 11, Structural Behavior of Bolted Joints
sive comb is free of adhesive residue.
of CMH-17, Volume 3, Materials Usage, Design and
Analysis.
7-7. MECHANICALLY FASTENED JOINTS. Mecha-
nically fastened joints in composites are signiicantly
7-33