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Perform Cable Analysis tab

Used to assign the commands required to perform a non-linear cable analysis on the model. This requires the presence of non-linear cables in the structure.

Note: Refer to TR.37.3 Nonlinear Cable Analysis for additional information.

Refer to G.8.2 Cable Members for an explanation of non-linear cable input options.

SettingDescription
Advanced Cable Analysis group

The options in this group are used to specify the advanced cable analysis feature and options specific to that analysis type.

SettingDescription
Advanced Cable Analysis

Set this option to specify an advanced cable analysis. Refer to G.17.2.8 Advanced Nonlinear Cable Analysis for details on the Advanced Cable analysis.

Note: Use of the Advanced Cable analysis feature requires the Advanced Analysis License. This option is the default if you have the license.
Use Modified Newton-Raphson Set this option to use the modified Newton-Raphson method, which can reduce computation effort in compared to the full Newton-Raphson method (at the expense of more iterations).
Use Geometric Matrix (Kg) Set this option to specify the use of geometric stiffness.
Cable Analysis Parameters group
SettingDescription
Steps Specify the number of load steps. The applied loads will be applied gradually in this many steps. Each step will be iterated to convergence. Should be in the range 5 to 145, with 145 as the recommended number.
Eq-Iterations Maximum number of iterations permitted in each load step. Should be in the range of 10 to 500, with 300 as the recommended number.
Eq-tolerance The convergence tolerance for the above iterations.
Sag Minimum Cables (not trusses) may sag when tension is low. This is accounted for by reducing the E value. Sag minimum may be between 1.0 (no sag E reduction) and 0.0 (full sag E reduction). As soon as Sag Minimum becomes less than 0.95 the possibility exists that a converged solution will not be achieved without increasing the steps to 145 or the pretension loads. The Eq-Iterations may need to be 300 or more. The Eq-tolerance may need to be greater or smaller.
Stability Stiffness Specify a stiffness matrix value that is added to the global matrix at each translational direction for joints connected to cables and nonlinear trusses for the first number of Load Steps. The amount added linearly decreases with each of the Load Steps. If a Stability Stiffness value is specified, it should be within the range of 0.0 to 1000.0. This parameter alters the stiffness of the structure.
Load Steps The number of load steps over which the Stability Stiffness is gradually applied. Default is one step.
KSMALL A stiffness matrix value that is added to the global matrix at each translational direction for joints connected to cables and nonlinear trusses for every load step. The range for KSMALL is between 0.0 and 1.0, with a default of 0.0. This parameter alters the stiffness of the structure.
Print Option Standard STAAD.Pro analysis print options:
SettingDescription
No Print No analysis results will be printed to the output file.
Load Data Prints all the load data.
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.
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.
Mode Shapes Prints mode shape values at the joints for all calculated mode shapes.
Both This option is equivalent to the Load Data plus Statics Check options.
All This option is equivalent to the Load Data plus Statics Check.