...
How
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can
...
I
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reduce
...
analysis
...
run
...
time?
...
ANSWER:
...
Apart
...
from
...
revising
...
the
...
model,
...
which
...
is
...
usually
...
best,
...
run
...
time
...
may
...
be
...
reduced
...
by
...
implementing
...
the
...
suggestions
...
which
...
follow:
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- Trim
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- earthquake
...
- records
...
- – Strong
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- shaking
...
- typically
...
- occurs
...
- over
...
- only
...
- a
...
- portion
...
- of
...
- the
...
- earthquake
...
- record.
...
- Maximum
...
- response
...
- should
...
- occur
...
- during
...
- or
...
- shortly
...
- after
...
- this
...
- period.
...
- It
...
- may
...
- be
...
- appropriate
...
- to
...
- trim
...
- the
...
- earthquake
...
- record
...
- to
...
- consider
...
- only
...
- the
...
- portion
...
- ranging
...
- from
...
- just
...
- before
...
- the
...
- onset
...
- of
...
- strong
...
- shaking
...
- to
...
- a
...
- few
...
- seconds
...
- past
...
- its
...
- decline.
...
- Increase
...
- the
...
- Overshoot
...
- Factor
...
- – When
...
- you
...
- set
...
- up
...
- an
...
- Analysis
...
- Series,
...
- it
...
- may
...
- be
...
- reasonable
...
- to
...
- use
...
- a
...
- larger
...
- Event
...
- Overshoot
...
- Factor,
...
- perhaps
...
- 5%.
...
- The
...
- default
...
- is
...
- 1%,
...
- which
...
- may
...
- be
...
- tight,
...
- especially
...
- for
...
- a
...
- large
...
- structure.
...
- This
...
- increase
...
- tends
...
- to
...
- reduce
...
- the
...
- number
...
- of
...
...
- events,
...
- thereby
...
- reducing
...
- the
...
- number
...
- of
...
- times
...
- the
...
- stiffness
...
- matrix
...
- is
...
- re-factorized.
...
- When
...
- setting
...
- a
...
- higher
...
- Overshoot
...
- Factor,
...
- be
...
- sure
...
- to
...
- check
...
- the
...
- energy
...
- balance
...
- at
...
- the
...
- end
...
- of
...
- each
...
- Echo***.txt
...
- file.
...
- Energy
...
- unbalances
...
- below
...
- approximately
...
- 5%
...
- should
...
- be
...
- acceptable,
...
- whereas
...
- larger
...
- unbalances
...
- may
...
- indicate
...
...
...
- in
...
- the
...
- analysis.
...
- Save
...
- fewer
...
- results
...
- – You
...
- may
...
- be
...
- able
...
- to
...
- save
...
- results
...
- every
...
- 2
...
- or
...
- 3
...
- steps,
...
- rather
...
- than
...
- at
...
- each
...
- step.
...
...
- plots
...
- will
...
- subsequently
...
- be
...
- more
...
- jagged,
...
- though
...
- demand/capacity
...
- ratios
...
- and
...
- usage
...
- ratios
...
- are
...
- always
...
- calculated
...
- for
...
- every
...
- step.
...
- Follow
...
- Capacity
...
- Design
...
- – Follow Capacity Design principles such that significant inelastic behavior is only present in some components and regions of the structure, rather than the entire structure. In doing so, it may be reasonable to model and design the remaining components to remain essentially elastic. This can substantially simplify the analysis model and reduce analysis time.