Equipment Effect in Structural Modle

[dozer]

I'm checking a structural model where the seismic loads were input by hand rather than using the load generation capabilities of the program. This is a structure which supports several pieces of equipment. The horizontal load on each piece of equipment was calculated based on the section of code entitled "Design of Parts and Components" and this was applied in the overall model.

I thought this section was for the design of the equipment itself and the anchorage of that equipment. I would have treated the equipment as extra mass on that floor so it would be part of the weight considered when doing the vertical distribution of the horizontal forces.

Which is correct? FYI, this particular case is using Australian Standard 1170.4-2007 but I have the same fundamental question when using a equivalent static analysis in any code that I am familiar with.

 

[MiketheEngineer]

If it is solidly bolted to the floor - I agree with you.

I do not know the AU code but in the US - there are different requirements.

"Hanging" equipment has much higher forces and I believe that is to justify the methods of attachment - primarily.

 

[aggman]

I always look at it as an additional mass. The parts and components would be for the machine attachment, at least that's what we do.