A “Toolbox” for Forensic Engineers

Fluid Transport 203
Tenacity (%)
100
80
60
40
20
60°C
(N)
40°C
(N)
0 5 10 15 20 25 30 35
Time of Exposure (Weeks)
Figure 6.25 Loss of tenacity of Terylene PET fibers (T) and nylon 6,6 fibers (N)
on continuous exposure to 10% sulfuric acid at various temperatures. 2
Figure 6.26 ESEM image of the final cusp on the fracture surface, with inner
bore at the top of the picture. Crack growth direction is shown by arrows. Several
major and minor striations are shown by the numbers at right.
the surface (Figure 6.24). Further intermittent growth then occurred in a
series of steps until the final cusp was reached with the junction hanging by
a thread. Further details of the fracture surface came with ESEM inspection.
Much finer striations were seen between the large crack arrest lines in the
ESEM (Figure 6.26). They showed that crack growth had occurred more
slowly than expected, with the crack jumping intermittently under very slight
25°C
(N)
40°C (T)
60°C (T)