Footfall analysis

[Anonymous]

Hi All 

Im fairly new to Robot. i have just designed a simple office floor plan, to run for footfall analysis. 

According t SCI for composite floors.

Could anyone please guide on the basics as to how to obtain the mode shapes and modal mass and frequency and R response factor for the floor.

thanks

[Artur.Kosakowski]

Hi @Anonymous

I'd suggest watching the recording of the 12th Robot webinar available from:

https://forums.autodesk.com/t5/robot-structural-analysis-forum/robot-structural-analysis-webinars/td...

If I managed to answer your question(s) press the Accept as Solution button please. This will help other users to find solution(s) much faster. Thank you.

[mustafahesenow · Accepted solution]

1

[Anonymous]

Hi Artur, thank you for the reply. i have had a look through the video earlier but still had a few questions. 

is dead load (self weight) and live load included in footfall. as SCI suggests 10% of the imposed load needs to be converted as permanent dead load. amd this seemed very confusing to do on Robot.

Reagrds

ibrahim. 

[Anonymous]

Hi Mustafah. i really appreciate the post. fantastic

it made it clear in terms of the loads involved. however you have put a coefficient of 0.1 for both DL and LL

in SCI only 10% of the imposed is  considered for footfall how does this work? 

Further on to this, i would like to compare my results with the Simplified method set out by SCI. this means the modal anaylsis has to be run. when i finished modal analysis the first mode shape gave me the fundamental frequency for the primary mode. i would like to know what the secondary mode could be as there are over 20 mode shapes and frequencies involved.

im sorry if my questions are unclear.

Ibrahim 

[Artur.Kosakowski · Accepted solution]

HI @Anonymous

is dead load (self weight) and live load included in footfall. as SCI suggests 10% of the imposed load needs to be converted as permanent dead load.

By default the footfall analysis uses the self-weight of the structure. You can include all other masses as selected load(s) to mass conversion with e.g. 1 factor for deal load cases (mind not to convert self-weight one as you double it unless you marked the disregard density check box in the parameters of the modal analysis cares) and e.g. 0.1 for live (imposed) ones.

If one or more of these posts answered your question, please click Accept as Solution on the posts that helped you so others in the community can find them easily.

[m_sheinin]

@Artur.Kosakowski  

I did watch webinar but I still have few question so the correct procedure is : 

1. Model you floor. 
2. Convert Live and addition dead loads to mass using factor. 
3. Create new analysis type (footfall).  When using this approach self weigh of the floor is included.

Thanks, 

Mike