RISA 3D

[Budding_SE]

Does anyone know how to apply the Hot-Rolled" rules to the General Material in Risa 3D? This is for custom shapes that i cannot define in the "Hot Rolled" shapes.

 

[flight7]

I don't know the answer, but call RISA technical support. They can probably give you an immediate answer over the phone.

 

[KootK]

I doubt this is possible given how difficult it would be programmatically. You might have have to wait for AI to take over.

 

[Aesur]

I believe KootK is right here, this is also a reason there isn't a software that designs aluminum (other than the most basic shapes) due to their tendency to always be custom shapes.

 

[WinelandV]

I assume by "Hot-Rolled rules" you mean the capacity determinations and unity ratio checks. If your section doesn't fit into a standard shape, then you'll have to check it by hand, using some combination of first principles and engineering judgement. RISA's code check algorithms certainly don't have any hidden knowledge that isn't in the AISC 360 (or your country appropriate steel code).

RISA checks channel sections in flexure via the equations given in AISC 360 Chapter F for channel sections - the same way it handles WFs, flat plates, and tube sections. Suppose you're making a crane beam with a WF and a channel hat - RISA has no direct way of checking that section. You might be able to get an approximation by forcing RISA to check it as a wide flange with unequal flanges, but it would be just that - an approximation.





Please note that is a "v" (as in Violin) not a "y".

 

[MotorCity]

What DOES Risa account for when using built up shapes? Not much left to check if its not performing a unity check. Maybe its just accounting for the member stiffness in the model? Seems odd that Risa would allow you to create built up shapes, but then not be able to see if they work. If the checks can be made by hand, I would think Risa would be able to make the same checks.

 

[Aesur]

The built-up shapes in RISA are limited to Wide Flange shape with varying sizes for web and flanges, because of it being limited to the WF shape it's easier to program for such calculations. I am not sure what shape the OP has but am guessing it's a combination of multiple shapes and not a WF type built-up shape.

 

[MotorCity]

Aesur - using Risa Section, you can create and import any custom section into a model (not just wide flanges).

 

[driftLimiter]

The custom sections in Risa can accurately determine the member stiffness, and stresses at the elastic level. But as mentioned above, it cannot apply design rules to custom shapes because the shapes are truly custom, and there is ample opportunity to make a non-typical shape. If the shape matches a standard shape then you might be able to just use a custom section of that shape and get code checks. If the shape is not the same profile as something that is built into Risa then you are left on your own to evaluate the stress limits etc.