Suspension Bridge - Cable

[MargotJulia]

I want to model my suspension bridge with a:
mid-span: 156 m
side-span: 52 m
sag: 10,9 m
pylonheight: 12 m

I have a problem with the input of the cable in SAP 2000

Material data:
full lock cable
weight: 83 000 N/m3
Modulus of elasticity: 160 000 N/mm²
Tensile strength: 1570 N/mm²
Yield strenght: 875 N/mm²

Cable section:
diameter: 70 mm

I made a cable between each hanger.
After every cable input, a window opens (=cable geometry) in which I didn't changed the settings.
Are the settings right or i have to change in the "cable geometry - window" something?

My problem is that when I let run the calculation and look at the deflection of the Dead Load, i get infinitely large deflections.

Another question is:
Where can I get the value of the cable-deflection?

I hope someone can help me with my problems!

 

[ishvaaag]

It may turn that your cable has not the necessary section and geometrical nonlinearities make that the analysis not converge to some finite value of deflection. Try a bigger section and see. Deflections can be read directly at the deformed shape pointing the node with the mouse, a box appears with the deflections. Post the zipped model and we can try your case.

 

[IJR]

just like ishvaaag said, post your zip file.

Another thing you can do is model the cable as frame elements with good meshing

Then define a load case consisting of all your loads

Define this case as a nonlinear case

The model will slow down due to iterative process involved, but you may get satisfactory results.

respects
ijr

 

[BridgeDOR]

Try with P-delta analysis.