JPE - Sept09 - cover2-4.pmd - Pipes & Pipelines International ...

156
Results
J-based limit loads -
dependence on applied load
Analyses using the above stress-strain model enabled the Jintegral
to be calculated as a function of the applied load
along the crack front. The highest J values, which generally
occurred at the middle of the crack front adjacent to the
smaller of the two ligaments (below and above the flaw),
were adopted.
The Journal of Pipeline Engineering
Pipe dimension
s,
mm
Flaw
dimension
s,
mm
Outside
diameter
Wall
thickne
ss
Height Length
Ligame
nt
to
ID
Ligame
nt
OD
E1BH3L50L1. 5M0
400 20 3 50 1. 5 15.
5
E1BH3L50L3M0400 20 3 50 3 14
E1BH3L50L14M0400 20 3 50 14 3
E1BH3L50L6M0400 20 3 50 6 11
E1BH3L50L9M0400 20 3 50 9 8
E1BH6L50L3M0400 20 6 50 3 11
E1BH6L50L11M0400 20 6 50 11 3
E1BH9L50L3M0400 20 9 50 3 8
E1BH6L50L6M0400 20 6 50 6 8
E1BH6L50L1. 5M0
400 20 6 50 1. 5 12.
5
E1BH3L25L3M0400 20 3 25 3 14
E1BH3L100L3M0400 20 3 100 3 14
E1BH3L200L3M0400 20 3 200 3 14
E1BH3L250L3M0400 20 3 250 3 14
Sample issue
E1BH6L25L3M0400 20 6 25 3 11
E1BH6L100L3M0400 20 6 100 3 11
E1BH3L25L6M0400 20 3 25 6 11
Table 1. Dimensions of pipe and flaw considered in finite-element analysis models (series E1).
The J results were used to estimate the following J-based
limit loads according to the approach described earlier:
• M J2B E – consistent with Equn 2, representing the
material-specific FAD of BS 7910 (Level 2B/3B)
and R6 (Option 2) with J e estimated using the elastic
pipe bending stress according to Equn 5.
• M J2B EP – consistent with Equn 2, representing the
material-specific FAD of BS 7910 (Level 2B/3B)
and R6 (Option 2) with J e estimated using the
elastic-plastic pipe bending stress in Equn 6.
to