Cables and modal analysis

[Anonymous]

Good afternoon,

I have the following doubts regarding how to work with cables and accomplish modal analysis:

1) CABLES

1.1. When I launch the calculations in the "Steel/aluminium design" module, Robot does not verify the cables. So,

can the ULS and SLS of the cables be verified using Robot? or the programme just allows us to define them and obtain the internal forces which we should later check on our own?

1.2. What should I do in order to define an appropriate material for the cable elements? the programme only lets me choose from a given lists of materials, so should I change the default properties of "STEEL" to have the properties that I need to use?

2) MODAL ANALYSIS

2.1.In order to determine the natural frequencies of any structure, is it necessary to generate additional nodes on every single member so as for the ressults to be more accurate or can the programme do it on itself? I ask this because I have modelled a simple cantilever beam and if I don´t create intermediate nodes the obtained results are not correct at all.

2.2. Is there any way of visualising the modal shapes?

I look forward to your reply.

[Artur.Kosakowski · Accepted solution]

1) CABLES

1.1. When I launch the calculations in the "Steel/aluminium design" module, Robot does not verify the cables. So,

can the ULS and SLS of the cables be verified using Robot? or the programme just allows us to define them and obtain the internal forces which we should later check on our own?

The Steel Design module is not intended for cables. 

1.2. What should I do in order to define an appropriate material for the cable elements? the programme only lets me choose from a given lists of materials, so should I change the default properties of "STEEL" to have the properties that I need to use?

You can create a new material in Job Preferences and use it for a new cable.

2) MODAL ANALYSIS

2.1.In order to determine the natural frequencies of any structure, is it necessary to generate additional nodes on every single member so as for the ressults to be more accurate or can the programme do it on itself?

I ask this because I have modelled a simple cantilever beam and if I don´t create intermediate nodes the obtained results are not correct at all.

You have to generate them manually. You can also set the mass matrix as consistent.

2.2. Is there any way of visualising the modal shapes?

As deformation diagrams. 

---

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.