Load Take Downs
Load Take Downs
(OP)
How do you guys like to do your load take downs?
Do you use FEM software, equivalent frame models or just do it by hand using tributary areas ?
I have been doing it by hand but i'm considering using SAFE. Just stripping down the architectuals and importing the floor plans in an assigning the relevant propeties.
Do you use FEM software, equivalent frame models or just do it by hand using tributary areas ?
I have been doing it by hand but i'm considering using SAFE. Just stripping down the architectuals and importing the floor plans in an assigning the relevant propeties.






RE: Load Take Downs
If there are transfer members or large variations in framing stiffness, the FEM takedown will often be very wrong, especially for transfer members where it will put too much load in non-transferred columns and not enough in transferred columns. This leading to under-design of tranbsfer beams.
RE: Load Take Downs
Mike McCann
MMC Engineering
RE: Load Take Downs
RE: Load Take Downs
RE: Load Take Downs
This allows for very basic checking of the model, making sure the model is basically correct, prior to a more in depth look at the members and stability.
RE: Load Take Downs
RE: Load Take Downs
RE: Load Take Downs
I agree with rapts comment, sometimes you need to take worst case scenario in some areas.
RE: Load Take Downs
RE: Load Take Downs
We have a spreadsheet setup for Load Take Down but, We would like to compare the results of FEM load reaction by hand. Using customized spreadsheet may be a great time-saver.
CAUTION: you may not get a proper load reaction from FEM anaysis unless the floor is 'properly meshed'
RE: Load Take Downs
As I said above, there is no problem with this except cases where there are transfers. Then the real situation is somewhere between tributary areas and FEM, but FEM definitely underestimates the reactions in the transferring columns unless you allow fully for construction sequence in all cases and stressing sequence if prestressed!
RE: Load Take Downs
Never, but never question engineer's judgement
RE: Load Take Downs