Robot Structural Analysis Forum
Welcome to Autodesk’s Robot Structural Analysis Forums. Share your knowledge, ask questions, and explore popular Robot Structural Analysis topics.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Footfall analysis result could not show RMS acceleration map?

9 REPLIES 9
SOLVED
Reply
Message 1 of 10
URSmodeller
1807 Views, 9 Replies

Footfall analysis result could not show RMS acceleration map?

Hi,

 

please refer to attachement.

 

I have complete footfall analysis, it appears only overall accelerations are avalaible in map, but RMS values.

 

Please can you advice?

 

Many thanks.

9 REPLIES 9
Message 2 of 10
Pawel.Pulak
in reply to: URSmodeller

Can you attach the model - saved without results and compressed to ZIP to reduce the size.

 

Regards,


Pawel Pulak
Technical Account Specialist
Message 3 of 10
Pawel.Pulak
in reply to: Pawel.Pulak

Hi,

attaching your file seems not necessary. I have checked it and Mean aRMS is not calculated for the following provisions:

"Concrete Centre (2006) slabs" and "AISC DG11 (2003) floors" because it is not required by them. See the attached screen captures. It is calculated for the other ones.

See also:

http://docs.autodesk.com/RSA/2012/ENU/filesROBOT/GUID-3AD2F89E-BA01-415F-80C5-C83E3902A47-733.htm

 

---------------------------------------------
If this post answer your question please click "Accept as Solution". It will help everyone to find answer more quickly!

 

Regards,


Pawel Pulak
Technical Account Specialist
Message 4 of 10
URSmodeller
in reply to: Pawel.Pulak

Ok, thanks lot.

 

If robot can also give RMS acceleration map before it be converted in to response factor would be handy.

Message 5 of 10
Pawel.Pulak
in reply to: URSmodeller

RMS acceleration map is displayed for SCI P354 provisions because it is used there (see the attached screen capture). Would you like something more?

 

Regards,


Pawel Pulak
Technical Account Specialist
Message 6 of 10
URSmodeller
in reply to: Pawel.Pulak

Hi Pawel ,

 

Thanks for your help.

 

One last question, for the concrete centre method, is overall maximum acceleration is sum of peak values from each harmonic or square-root sum of square?

 

Thanks.

 

 

 

 

Message 7 of 10
Pawel.Pulak
in reply to: URSmodeller

As written in the help topic mentioned by me before (http://docs.autodesk.com/RSA/2012/ENU/filesROBOT/GUID-3AD2F89E-BA01-415F-80C5-C83E3902A47-733.htm) it is calculated as the square root of the sum of squares):

 

 

The response factor for the harmonic component h:

Calculate the overall response factor for the resonant response analysis as a square root of the sum of squares of 4 response factors for the harmonic components.

 

Regards,


Pawel Pulak
Technical Account Specialist
Message 8 of 10
URSmodeller
in reply to: Pawel.Pulak

Hi Pawel,

 

Thanks your swift response.

 

My question is about "overall max a" not response factors. For clarification, please refer to attached pics and extract from your help doc. below.

 

"You can select the following maps in the dialog:

·      maximum response factors (for the resonant and transient response analyses)

·      mean velocities (RMS, RMQ)

·      acceleration (overall maximum, mean aRMS).

The mean acceleration value aRMS (Root Mean Square) is:"

 

Cheers.

 

Message 9 of 10
Pawel.Pulak
in reply to: URSmodeller

Hello,

for "overall max a" it is the same - it is calculated as SRSS combination of accelerations of harmonics.

See the attached screen capture confirming it - especially the table below footfall analysis diagrams.

sqrt(4.7*4.7+2.8*2.8+0.7*0.7+10.9*10.9)= 12.2 mm/s2

 

Regards,


Pawel Pulak
Technical Account Specialist
Message 10 of 10
URSmodeller
in reply to: Pawel.Pulak

Hi Pawel,

 

Excellent, many thank you for the help.

 

 

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Autodesk Design & Make Report