Acceleration Loadings

[Mark1arm]

Hi,

A customer has asked us to consider loadings of 4g in the X,Y & Z direction of a vessel supported on saddles.

Can anyone point me in the right direction with such a problem. Is this something that could be analysed by FEA or, am I over complicating the problem? Is this seismic/harmonic?

Thanks.

 

[XL83NL]

Isnt this pretty straightforward, F = m times g, added as load in Newtons? If Im not mistaken, seismic loads in piping stress analysis, when expressed in g's, are considered (quasi-)static loads. So that'd mean you can add (assuming SI units) approx 40 times the mass, as extra force in all 3 directions, in units Newtons. Not sure, maybe Im completely off, but this came to mind first.

 

[Mark1arm]

Thanks, I'm not too sure to be honest the specification was pretty vague, simply asking to consider the mentioned loads. Our primary PV Engineer left us a couple of weeks ago so we are trying to figure out what we need to consider and how we go about applying such loads.

Obviously familiar with F=mg but where and how do we integrate this into the design, just fishing for ideas to see if we need to farm the design out or if we can do it in house.

 

[XL83NL]

Farming out is better when such questions are asked

 

[NRP99]

Mark1arm

You can consider this acceleration load analogous to transportation load case and can evaluate the vessel. Refer book- Pressure vessel design manual by D Moss.

If you are interested in the saddle to vessel stresses, above book procedure provide the stresses in saddles and vessel saddle junctions.

If interested in overall vessel stress levels, you need to do FE analysis of vessels for 4g acceleration load.