Autodesk Robot Structural Analysis

[#1]

Hi,

I am trying to design a concrete block foundation for a 60m high chimney. from the supplier I have the values of the vertical force and bending moment from the wind.

I am designing the block in RSA as a volume structure model, my question is, if the forces can be applied in a node in the centre of the block, will this be a good solution?? in case not, please any idea in this concern???

Thanks

[#2 · Accepted solution]

No as you cannot apply bending moment in this way (nodes of solids have only 3 d.o.fs). I'd rather apply the load to a node being slightly above the foundation and connect this node with nodes defined on a circle that stands for the chimney perimeter using rigid links or fake rigid bars.

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.

[#3]

Thank you

[#4]

Hi,

what is the option in mesh generation for the nodes to interact???

Thanks in advance!

[#5]

What was the way you created the solid? the vertical extrusion of a circle?

[#6]

as an object

[#7]

Try the way shown on the attached pictures.

[#8]

Thanks, in this case it works,

volume modeling is for stresses and displacement results, in order to obtain moments , membrane forces and reinforcement design, the block must be designed as a plate? or it can be done in the volumetric option of RSA?

I tryed to model the block as a plate, placing rigid links and the soil effect is modeled as a area spring (winkler method), in this case there is ERROR - forbiden use of compatible node or a support in slave node of the rigid link. Any idea in this regard??Maybe the use of stiff bars??

Thanks in advance

[#9]

---

volume modeling is for stresses and displacement results, in order to obtain moments , membrane forces and reinforcement design, the block must be designed as a plate?

Correct. These kinds of results are available for panels only.

I tryed to model the block as a plate, placing rigid links and the soil effect is modeled as a area spring (winkler method), in this case there is ERROR - forbiden use of compatible node or a support in slave node of the rigid link. Any idea in this regard??Maybe the use of stiff bars??

Either stiff bars or Rlinks.

---

[#10]

maybe this is the answer to my previous answer, the block thicknes design option, in this case, includes also the option of parameters of foundation elasticity. and there can be added the values for modulus of subgrade reaction Kz in KN/m3.