S-FRAME curved member analysis

Andrew Thomson

I have a vertically curved member created by a number of joints. S-FRAME seems to be lacking the ability to consider all of the individual beams as on simply supported member (continuous across the joints) when you can't turn on physical member modelling and drag a member across all of the joints. Is there any functionality or work arounds within the software to run a proper analysis of the curved member? Thank you!

Screenshot of curved member.png

Andres Chavez

Hello Andrew,

 

Thank you for getting in touch. This is Andrés, from Altair's Technical Support, and I'll be glad to answer your question.

We appreciate the elaboration and sending the screenshot along. In this case, we must clarify that there is no direct way to do this, but we could suggest the following workaround:

You can draw your straight, physical member first and introduce the intermediate nodes:

Then, we can try increasing the model tolerance such that any deviation from the straight line will be within the specified tolerance, and adjust the locations of member joints afterward to form the curve:

Finally, after clicking on 'OK', S-FRAME will update the member with the new joint locations. It is important to clarify that even though the physical member will be drawn in a straight path in S-FRAME, the analytical nodes that comprise the physical member will fall at the specified locations:

When doing this, S-STEEL will treat the underlying analytical members as one physical member, but the design length would not be correct and would need to be modified using the unsupported length factors. You must be cautious, as the Model Tolerance will also affect other unrelated numerical error issues while 'supporting' this feature, so we'd recommend checking if undesired issues are generated after increasing the Model Tolerance. This can be done by simply converting the physical model to an analytical model and doing a visual inspection of this analytical model to check if it's correct, from an analytical point of view.

 

We hope you find this information helpful. Please let us know if there are any additional questions in this regard.

 

 

Kind regards,

 

Andrés Chávez Burgos

AEC Solutions Engineer