P Delta Method |
Select one of the following options:
Setting | Description |
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Large and Small Delta
|
Select this option to include both P- large and small
Delta effects (recommended), sometimes referred to as P-δ & P-Δ.
Both the large & small P-Delta effects are included in calculating
the end forces, (5 to 10 iterations will usually be sufficient).
|
Large Delta only |
Only include the "PlargeDelta" effects (P-Δ only). STAAD.Pro performs a first order linear analysis
and obtains a set of joint forces, from members/plates based on the large
P-Delta effect, which are then added to the original load vector. A
second analysis is then performed on this updated load vector. |
Stress Stiffening (KG)
|
P-Delta analysis including stress stiffening effect of the KG matrix. With this option the global stiffness is adjusted with every iteration.
A regular STAAD.Pro P-Delta Analysis performs a first order linear analysis and obtains a set of joint forces from member/plates based on the large P-Delta effect. These forces are added to the original load vector. A second analysis is then performed on this updated load vector (5 to 10 iterations will usually be sufficient).
In the new P-Delta KG Analysis, that is, with the Kg option selected, the effect of the axial stress after the first analysis is used to modify the stiffness of the member/plates. A second analysis is then performed using the original load vector. Large & small P-Delta effects are always included (1 or 2 iterations will usually be sufficient).
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Number of Iterations (n)
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Specify the number of iterations to be performed. If specified, the program will perform the specified number of iterations whether or not the solution converges. |
Print Option |
Standard STAAD.Pro analysis print options:
Setting | Description |
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No Print
|
No analysis results will be printed to the output
file.
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Load Data
|
Prints all the load data.
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Statics Check
|
Provides a summation of the applied loads and support
reactions as well as a summation of moments of the loads and reactions taken
around the origin.
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Statics Load
|
Prints everything that
Statics Check does, plus a summation of all
internal and external forces at each joint. This option potentially generates a
large volume of output.
Note: Since
PRINT STATIC LOAD generates voluminous output, the
printing of summation of internal and external forces at each joint is done for
structures which have less than 1,000 joints. If the structure has 1,000 joints
or more, this printing will be skipped.
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Mode Shapes
|
Prints mode shape values at the joints for all
calculated mode shapes.
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Both
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This option is equivalent to the
Load Data plus
Statics Check options.
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All
|
This option is equivalent to the
Load Data plus
Statics Check.
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