ssc-367 - Ship Structure Committee

MODELING ERROR (Xme)
: Typically defined as the ratio of actual
behavior of the structure to the one predicted
by the model. It is often used to assess the
accuracy of excitational loads, motions, and
stresses.
MODELING UNCERTAINTY
NARROW-BAND LOADING
: The random component of the modeling error,
x, and defined by its coefficient of
v%iation, (C.O.V.)X .
me
: The stress cycles are readily identifiable,
making the choice of counting method of stress
cycles immaterial.
NOMINAL STRESS
: The nominal stress is the stress obtained by
dividing the member generalized forces (forces
and moments) by member section properties
(cross-sectionalarea and section modulus).
OPEX
: Operating expenditures due to maintenance,
inspection, repairs as well as cost of fuel,
variables,personnel,etc. during the life of a
structure.
PLASMA DRESSING
: Application of plasma arc welding technique to
remelt the weld toe (similarto TIG dressing)
POST WELD HEAT TREATMENT
(PWHT)
: A procedure of heating a welded joint to
relieve residual fabrication stresses.
Typically, the joint is heated to 1076 1150°F
(580-620”C), held at that temperaturefor about
an hour for each one inch (2.5 rein/mm)
thickness, and cooled in air.
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