Linear And Non-Linear cable analysis (and output data)

[engABZ]

Hello
I want to use STAAD cable analysis to analyze a cable (pinned support at both ends) having udl all over the span (20-30)m.

I don't know the unstressed length (is it the length of cable before loads are applied?), so I think I can't do Non-linear analysis.

So in this case would be the linear analysis accurate enough?

For linear analysis, the output shows a list of iterative steps, and in each step it provide a (% of load), iterations ends with 100% use of load. Does this part of output has something that I should consider? (What is it telling me?)

Thanks in advance

 

[engABZ]

sorry, regarding what I mentioned of linear analysis, I meant using Initial tension parameter instead of Unstressed length (which still enables Non-linear analysis).

 

[JoshPlumSE]

Not sure doing cable analysis in STAAD is such a good idea. Has anyone else done this?

Has anyone verified the behavior of the STAAD cable element compared to hand-calc catenary cables or another respected program that does non-linear cables(SAP?).

If you were talking about using simple straight line guyed cables, that would be one thing. But, applying a transverse distributed load. That requires a bit more advanced behavior. I'd want to have a really good verification problem proving STAAD's capabilities in this arena before I would use it.

 

[engABZ]

Thanks JoshPlum
So you recommend using SAP in this case?
Have you used it before for similar situation?

 

[JoshPlumSE]

I have not used SAP for this. But, being a more bridge oriented program with a reputation for non-linear analysis I would feel more comfortable with it.

It's really just that cable elements loaded transversely are highly non-linear.

If you choose to use STAAD, I don't necessarily have a problem with that. But, given their historic weaknesses related to non-linear analysis I would look at those results a bit more closely. In fact, I'd start of by running some very detailed verification problems on these types of elements. Ones where I have a known solution that I can confirm against the program results.