ssc-367 - Ship Structure Committee

ages. The designer has no control over the environment, but other
factors can be addressed to enhance fatigue quality.
The factors that affect fatigue quality can be reviewed in four
groups. It appears reasonable to assume that each of these four
groups contributes equally to fatigue failure:
●
●
●
●
Design
Fabrication
Maintenance
Operational Loads
The fatigue life of a vessel is similarly affected by the activities
undertakenduringdesign,fabrication,maintenancework and severity
of operational loads. Skaar (Reference9.1) reports that a survey
to assess the approximate importance of design, fabrication,
maintenance and operations indicated that each contributes about
equally to overall quality.
9.2
BASIC FATIGUE AVOIDANCE STRATEGIES
9.2.1 Basic Premises
Review of fatigue failures shows that while relatively few failures
threaten structural integrity, repairs are costly and the cost of
continuous inspection and maintenance is appreciable. A survey of
design configurations and structural details shows that designers
who have access to operational feedback on inspection, repair and
maintenance, generally develop more reliable designs. To ensure a
functional,high-qualitystructure(i.e.,with structural integrity)
that is cost-effective, both capital expenditures (CAPEX) and
operating expenditures (OPEX) should be addressed simultaneously.
The review of marine structures indicate several design
philosophies:
9-2