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Analysis of Failed
Engineering Materials
Materials failure is the inability of a component or
assembly to function properly, which may result in
fracture. Common examples include the failure of
high load bearing components such as crane jibs,
crane joints and hoisting ropes (Photographs 1 and
2). The extent of the failure in each case can vary
both in type and magnitude.
The role of the materials analyst is to determine
how a material failed. Knowing how the material
failed will allow the analyst to determine the cause
and if it was related to a failure such as human
error, a design/manufacturing flaw or poor material
specifications. With this knowledge, the analyst is
able to assist in preventing similar events from
occurring.
Engineering failure occurs when the material is no
longer capable of carrying the load for which it was
designed. As the material is overloaded, cracks can
initiate and grow, eventually leading to failure,
possibly in a catastrophic manner.
The most common failure mechanisms are corrosion,
fatigue, ductile/brittle fracture, overload, hydrogen
embrittlement, creep and wear. Cracks propagate in
characteristic ways and as such can be used to
identify the failure mechanism. The origin of the
failure and the characteristic crack patterns can be
determined using a stereomicroscope (low
magnification) and/or a scanning electron
microscope (high magnification).
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Photograph 1 Collapsed jib of a tower crane
(image courtesy of Vertikal).
Photograph 2 Broken Reachstacker crane joint.
Fire and explosion investigation
Chemical and fuel cargo contamination
Self-heating and coal cargoes
Spoilage of bulk agricultural cargoes
Cargo liquefaction
Advice on dangerous cargoes
Post-incident desktop review and analysis
Assistance/attendance at ‘live’ incidents
Materials failure analysis
Corrosion and metallurgical analysis
Dr John Allum
+852 9094 7867
Nico Zurcher
+852 6209 5144
Dr Sophie Parsons
+852 9037 0526
Dr Josephine Long
+852 6287 6065
Iris Wong (Accounts)
+852 2548 0577
Analysis of a sample from a corrosion case under low magnification can indicate the extent of the
damage by determining the depth of the corrosion pit (Photograph 3). Metal fatigue failure
requires visual assessment to locate beach marks, and may often requires higher magnification
analysis to identify characteristic striations which lie between the beach marks (Photograph 4).
Mechanical tests and chemical analysis can also be carried out to investigate whether the failed
material met its original engineering specifications and if it conformed to its required grade.
Usually, the investigation process will include a site inspection, a review of relevant design,
maintenance and operation logs, witness interviews and a detailed examination of the failed
components. Putting all of this information together will help to establish the sequence of events
that led to the failure, thereby allowing the cause of the material failure to be determined.
Photograph 3 Corrosion pit in steel. Photograph 4 Fatigue striations, beach
marks, on steel fracture surface.
0.2 mm
Fire and explosion investigation
Chemical and fuel cargo contamination
Self-heating and coal cargoes
Spoilage of bulk agricultural cargoes
Cargo liquefaction
Advice on dangerous cargoes
Post-incident desktop review and analysis
Assistance/attendance at ‘live’ incidents
Materials failure analysis
Corrosion and metallurgical analysis
Dr John Allum
+852 9094 7867
Nico Zurcher
+852 6209 5144
Dr Sophie Parsons
+852 9037 0526
Dr Josephine Long
+44 792 048 6646
Yvonne Tung
+852 6287 6065
Hannaford Forensic Services has been conducting independent investigations for over 20 years
and employs a team of experienced and qualified scientists and engineers. Please contact a
member of the team to discuss the range of services that we can offer.
Emergency Contact: +852 2548 0577 (24 hours)
