(1)The effects upon the operation of the sensitive equipment
within the chamber, and
(2) The effects upon relatively flexible piping or other
connections between various components of the chamber.
d.
Fatigue Strength. Evaluate the fatigue strength if stress
reversals or large changes in stress magnitude occur frequently due to the
operation of the chamber components or its auxiliary support equipment.
3.
DESIGN PARAMETERS PECULIAR TO EACH MATERIAL.
a.
Structural Steel. When the facility is designed of structural
steel, consider the following parameters as they relate to the response of
the structure, and its effects upon the chamber and its supporting equipment.
(1) Joint slippage in bolted connections should be avoided by
conservative design and the use of high strength bolting designed for
friction type connections.
(2) The use of high strength steels should be studied in regard to
their total deflection and rigidity before being incorporated into the final
design. Deflection is directly proportional to the bending stress so the use
of high strength steel results in correspondingly higher strains being
induced into the chamber and its components.
(3) Depending on the area climatology, and the design and use of
the facility, the thermal effects upon the framing should be evaluated.
Detrimental movements may result from thermal expansion and contraction of
the chamber components and the steel framing itself.
(4) The corrosion of the structural steel may be a problem in
coastal regions where the steel framing is subjected to salt air environment
or in areas with high industrial air pollution incorporating corrosive
agents.
b.
Reinforced Concrete. When the facility is designed of reinforced
concrete, consider the following parameters as they relate to the response of
the structure and its effects upon the chamber and its supporting equipment.
(1) In addition to normal initial deflection under application of
load, reinforced concrete will continue to deform or creep for several months
or even years after the load has been applied. This time dependent movement
must be taken into account in the design of the structure in much the same
manner as that used for considering the differential settlement in the
foundations.
(2) Reinforced concrete will shrink as the concrete dries, either
naturally or at an accelerated rate due to a heated environment in which it
is enclosed. Shrinkage warping is a movement similar to load deflection and
is a potential source of strain upon the chamber or its components.
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