Ram Element V13.5 Bug

Thanaana - I am moving your query to the correct forum. Someone will respond shortly. There is no need to create multiple queries.

Regards,

Hi Duncan,

Thank you for your recommendation.

I'm a new customer of Bentley and new member of the communities also.

Actually, I'd like to create only one query but it seemed the first one was deleted due to my mistake, that's why I repeated the post again.

I met some problems about the product and I've no idea how to contract technical support directly.

Thank you,

Thanaanan

Hi Thanaanan, 

This is as good as place as any to request support. It can also be beneficial to other users when you post in forums as they may have similar queries.

You can get to your own Community quickly from the opening page



Click into the "Go to a topic or product community", select the Community that is most suitable, then click the "Go" button. 

You can also use the tools on the Community landing page to bookmark the page or set up email digests which will keep you informed of anything new.

Regards,

Your model has a custom shape in it called F 2000508, try editing that section using the check box for "Laterally restrained for torsion".  This forces the member forces to be in the local axes not the principal axis which might be triggering your symptom as the tapered members principal axis can change based on section depth. 

The other thing to try is running it with no offsets or cardinal point changes to see if the rigid links are somehow causing it. 

Dear Seth,

Firstly, thank you for your advices.

I try to investigate the symptom using a very simple model (see picture A). The result of Ram element are compared to STAAD Pro results.

The model is a wide flange with web-tapered column. No node offset, but the member is not aligned vertically, this is to make the exact column center of gravity alignment. 

I try to vary the bottom end depth of column from 200mm to 400mm (The top end is fixed). The results shown that, the moment distribution shape obtained from STAAD Pro is the same for all range of the bottom end depth and no out-of-plane bending occur (See picture C). In contrast, the results yielded by Ram element is different. The result of 300mm and 400mm bottom end depths are the same as STAAD Pro,  but the result of 200mm bottom end depth is strange. The moment distribution shape is different and out-of-plane bending occur (See picture B).

In my opinion, the problem may caused by Metrix stiffness or Transformation Matrix that the program (Ram Element) used for analysis.

I will inform you again If I know more.

Cheers,

Thanaanan

Picture (A)

I

Picture (B)

Picture (C)