Self weight moment - Pretensioned Beam

[Anonymous]

I am using Autodesk SBD 2019 (Version 19.1.958.0) and am having issues with the pretensioned beam with a varying cross section. Previous versions of SBD use to calculate the self weight moment taking into account the varying cross section but this version calculates the self weight moment based purely on the section being analysed. For example for a certain position along the beam where the cross section changes the self weight moment is different depending on the section which is immediately either side of this point. The self weight moment instead at each point with differing sections either side should be equal. This results in weird transfer stress diagrams, inaccuracies in calculating elastic shortening losses and transfer deflections. 

[dave_geeves]

Hi,

I wasn't aware of any problems in the calculation of self weight moments for this type of beam but I would be happy to take a look if you could zip up your data file and attach it to a reply to this post. 

Thanks

Dave Geeves

[Anonymous]

Hi Dave

We have just updated to ASBD 2019 and previous to this update the software always calculated the correct self weight moment for a beam with a varying cross section (I have been using SAM/ASBD for over 12 years). My colleague brought this to my attention yesterday so I created a quick beam module to check if I was getting the same error which I was. I'll send through the beam module I created in a subsequent post.

[dave_geeves]

Hi,

Thanks for the additional information.  I did try creating a test beam myself and I can confirm that my initial findings is that I also find a problem with the calculation of self weight moments for some situation where there is a varying cross section. This was done using 2019 version, but I now need to run some checks with previous versions as , like you, I thought that this situation had always yielded the correct results before.  I'll keep you posted.

Regards

Dave Geeves

[dave_geeves]

Hi Brendan,

I have built the same beam in 2018 and it works fine.  It seems there is a problem with the 2019 version, so I'm afraid the workaround is to go back to the 2018 version.

I know that the developers read these posts so hopefully it will be rectified in an update at some time.

Regards

Dave Geeves

[karoly_tarcsi · Accepted solution]

Hi Brendan,

Thanks for your post. Sorry for the late response, I failed to notice this one earlier...

Correction will be included in the earliest possible major release of the software.

Btw, thanks for your insightful comments/posts. May I ask the name of your organization?

Regards,

Karoly Tarcsi

Software Development

[karoly_tarcsi]

Hi Dave,

Thanks for your comments/posts. ASBD community really appreciates your expertise and contribution.

Best regards,

Karoly Tarcsi

Software Development

[Anonymous]

Thanks Karoly

No worries, I work for an organisation in Australia called Aurecon.

https://www.aurecongroup.com

Regards

Brendan