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This page is devoted to *frequently asked questions* (FAQ) related to [cables|kb:Cable].
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h5. How is initial cable length and geometry calculated when multiple point loads are applied? {open-question}

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h2. Should a load which represents initial cable conditions be applied before subsequent nonlinear analyses are run for additional external loads?

*Answer*: Yes, in most cases, it is a good practice to assign a load which represents initial cable conditions. This is done using the Cable Geometry menu. Initial cable tension is dependent upon initial geometry and applied loading. Given distributed loading on a single cable with fixed supports, the cable drawing tool can calculate this tension. Full analysis must be implemented for systems of cables, cables connected to flexible structures, and conditions where additional loads are applied. The best approach depends on what information is known and how the structure is to be built. If cable length is known, a simple nonlinear analysis procedure should be sufficient. Otherwise, initial-geometry iteration or target-force loading may be necessary.

Once the initial shape and tension of a cable is determined, further analysis is necessary when additional loading is applied. Nonlinear analysis is also recommended. Video 16 of the SAP2000 {new-tab-link:http://www.csiberkeley.com/sap2000/watch-and-learn#page=page-1}Watch & Learn{new-tab-link} video series provides excellent instruction on this topic.


h2. In normalconventional static -linear analysis, isdoes calculation theconsider cable stiffness considered in calculations or not?

[Nonlinear analysis DRAFT] is requirednecessary to getgenerate meaningful results withconcerning the cable elementbehavior. LinearUsers analysismay canperform belinear performedanalysis, butthough theycable shouldstiffness alwaysvalues useshould thebe stiffnesstaken from the end of a nonlinear static-analysis analysis[load case in which all|kb:Load case] where cables are loadedsubjected byto theirall selfloading weightconditions, or otherincluding self-weight, transverse, loadsetc. ForWhen casesa wherecable nowith transverse loadslack is presentnot onsubjected ato slackany cableform elements,of thetransverse program will internally assume loading, a verynegligible small self-weight loadis inimposed order to obtainenable athe unique shapeformulation. However, it is betterbest ifto you apply athis realisticself-weight load for this purpose manually such that it is of realistic magnitude.


h2. Why do I see are the cables of my model returning nonzero moment diagramvalues?
on
theObjects cablesintended into mybe model?cables would Yougenerate maybending beresponse modelingwhen the cablemodeled using straight frame objects. If thismoment isvalues theare casereturned, please uncheckusers should model cables as catenary elements by unchecking the "Model Cable Using Straight Frame Option"option on the "Cable Geometry" form to model the cable as a catenary menu.


h2. How can I displayis the wind loadingload applied to thecables cablesdisplayed?

Users Youmay aredisplay ablewind toload useusing the Display Display>Show> Show Load Assign>FrameAssign > Frame/Cable/Tendon menu command. To assign wind load to displaycable elements, the wind loading on the cables. Please note that to generate wind loading on cable elements; you should define the auto load pattern to use Exposure from Frame Object. auto load pattern should be defined using the Exposure from Frame Object option.

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*Question*: How is initial cable length and geometry calculated when multiple point loads are applied? {open-question}

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