Pipeline and piping have been widely used for decades in the transportation of enormous kinds
of fluids in diverse industries (e.g. oil and gas, chemical and power industries). During the
construction phase of these pipelines, different sizes of pipes (ranging from 2" to 48" or more),
elbows and piping are welded to meet the required design criteria and mechanical properties.
With these in mind, a lot of factors must meticulously be considered to ensure that the finished
weld is suitable for use in all ramifications. This is done in accordance to set down codes and
standards to avoid the possibility of failure. Even though there has been destructive analysis
carried out on the welded joint to ascertain the required minimum mechanical properties, however
scanty numerical and non-destructive analyses are usually performed in line with the established
standards. Therefore, this paper focused on the numerical (modal analysis using ANSYS R15.0
explicit dynamic modeler) and non-destructive (TOFD: time of flight diffraction) analysis on a 4”
butt welded pipe.
The result from the numerical analysis clearly showed the effects of the discontinuities on the
welded joint where discontinuities exist as equally confirmed by the non-destructive inspection.
These parts exhibited higher stress concentration as compared to other parts that do not have
any form of discontinuities and this relates to the fact that the presence of these discontinuities
will accelerate the failure of the welded joint even though the applied stress at those points is
much lower than the yield strength of the material.