Analysis of shell failure of a semi-trailer tanker used for hauling petroleum products

Abstract

Failures of heavy-duty vehicles during load hauling are major concern in
road transportation. This is due to the magnitudes of accidents that
sometimes result from the failures with loss of lives, destruction of goods
or spillage with treat to environment, and road blockages. The failures
are particularly detestable to the vehicle owners owing to the much loss
they can incur including litigations they can face and compensations they
can be obliged to make to affected innocent victims. In this paper, shell
failure analysis of a semi-trailer tanker owned by an oil marketing
company which resulted in much loss of its full-tank carried oil has been
investigated. The information provided can be useful for forestalling
recurrent failure problems with the company’s fleet of semi-trailers
which had caused the company substantial losses in its annals. The shell
was first examined visually to assess the nature and magnitude of the
failure and where it occurred. Maintenance records of the vehicle was
surveyed and collected samples from critical locations of the shell was
analyzed with respect to chemical composition, metallographic structure,
and corrosion behaviors. Visual inspections indicated that the shell failed
by small brittle crack perforation along the seam of a previous weld
repair. Surveys showed no clear standard maintenance records of the
semi-trailer. Chemical analysis showed steel material of different
composition at the failure location compared to the as-made shell carbon
steel. Metallographic analyses showed that the failure location was
heterogeneous compared to the as-made shell steel. Corrosion analyses
showed greater corrosion rates at the failure location which presumably
raised the location stresses amid dynamic effects from bad road
conditions and caused the shell to crack-perforate along the weld seam
of the location.