Cable Layout Form
Defining Cable tension in the cable layout does not generate prestressing force. Cable layout is only used to determine the length of the cable that is added to the model. It is a drawing tool. It assumes fixed points of support and only gravity load acting. In the actual model, the supports may move, many different loads can be applied to the cable and the rest of the structure, and these loads may differ from one load case to another.
If the length of the cable is longer that the chord length (distance between the joints), it will have no initial tension in the model, no matter how it was drawn. If the cable is shorter that the chord length, then initial tension will be induced. The actual tension will depend upon support flexibility.
Aside from this effect, tension in the cable must be generated by applied loading. Tension can be generated by applying gravity load, by applying strain or temperature load, or by applying target force loading. When applying gravity, strain, or temperature load, the resulting tension will depend on the shape of the cable and the movement of the supports due to flexibility and other factors.
Only target force loading is capable of applying a specified tension in the cable, when possible, and this is an iterative process due to all of the factors mentioned above.
Notes
- accessible via Edit > Edit Line > Edit Cable Geometry
- relative length is length of the cable divided by the length of the cord connecting the beginning and end points