cranfield university mahadi abd murad an integrated structural ...

maximum local stress at discontinuity could be many times greater than the nominal
stress of the pipe. To evaluate the corrosion damage in the region of local wall thinning,
an SCF is needed as a function of defect geometry, pipe geometry and loading, as
reported by Kim and Son (2004). Hence, the values of the elastic stress concentration
factor for pipes with local wall thinning, subject to internal pressure and global bending,
using 3D elastic FEA (ABAQUS) have been established. The defect has been modelled
as a circular shape in both axial and circumferential directions inside the pipe.
De Carvalho (2005) also demonstrates in the same way as Kim and Son (2004)
but with a radial u-notch inside the pipe instead. However, they all refer to maximum
hoop stress at the notch root being determined by the finite element method. For the
nominal hoop stress, De Carvalho (2005) refers to it as being calculated at the same
point in the thickness and the expression which describes hoop stress acting in a
perfectly cylindrical region as;
Equation 2.1)
Where P is the internal pressure, , and r are the inside, outside and a given radius.
The schematic representation of the model is shown in Figure 2.18.
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