Civil Engineering Reference
In-Depth Information
Small CA
Med. CA
Large CA
Fig. 9.4
Enhanced asperity specimens [
6
]. The profiles for the enhanced asperities were cut using
an EDM. There are three types of enhanced asperities (small, medium, and large contact area)
Fig. 9.5
Determination
of apparent contact area
for enhanced asperity
specimens [
6
]. This scheme
accompanies the equation
to determine the apparent
contact area of enhanced
asperity specimens
where
D
is the outer diameter of the specimen,
L
1
is the length of the first cut,
L
2
is the length of the second cut,
L
3
is the length of the third cut,
L
4
is the length of
the fourth cut, and
w
is the width of each cut.
Table
9.2
shows the designations (surface ground, Large CA, Med CA, and
Small CA) and the corresponding contact areas.
9.1.3 Post-forming EAF Roughness Examination
In this subsection, post-formed surface roughness values were determined for
4.76-mm-diameter specimens formed using conventional compression and EAF
tests (at current densities of 20 and 30 A/mm
2
). The same measuring strategy
as discussed in the previous subsection was used. The total displacement stroke
