...
How
...
is
...
a
...
frame
...
assigned
...
a
...
sidesway-uninhibited
...
condition,
...
rather
...
than
...
sidesway-inhibited?
...
Extended
...
Question:
...
Further,
...
should
...
I
...
use
...
the
...
effective
...
length
...
factors
...
automatically
...
calculated
...
through
...
...
?
...
K
...
=
...
1.0
...
for
...
all
...
members
...
under
...
any
...
configuration,
...
which
...
does
...
not
...
seem
...
accurate.
...
Should
...
K
...
factors
...
be
...
input
...
manually?
...
Answer:
CSI Software implements a rigorous process to determine K factors. A full description is available in the CSI Steel Frame Design Manual (Help > Documentation > Design > Steel Frame Design > Design Algorithms > Element Unsupported Lengths > Effective Length Factor).
A notable point mentioned in this section (pages 11-14) is that K-factor calculations are based on the assumption of uninhibited sidesway. For other cases, K factors should be specified by the user. Users should always, however, use engineering judgment to evaluate the accuracy of K factors calculated by computational tools. Any discrepancy between the unbraced properties modeled and the actual design intention may lead to inappropriate design.
Automatically-generated K factors may be overwritten for individual members using the Overwrite option under Stress Check Information, as shown in Figure 1:
Figure 1 - Frame-property overwrite
See Also
- Sway and nonsway conditions article