As per TEMA Table D7M, the density of austenitic stainless steel (Type 3xx stainless steel) is 1.02 times that of carbon steel whereas ferritic/martensitic stainless steel (Type 4xx stainless steel) is 0.99 times that of carbon steel.

However, (if my memory serves me correctly) the density of austenitic stainless steel (like SA-240 304L) is considered as 7750 kg/m3 in PVElite which is LESS than the density of carbon steel considered as 7833 kg/m3. I am not sure about the latest build / versions of PVElite.

If we go by TEMA D7M, then the density of austenitic stainless steel works out to 1.02x7850= approx. 8000 kg/m3 (in lieu of 7750 kg/m3 considered by PVElite). The difference (though minor) would still influence the weight (and therby material tonnage/commercial impact) and seismic calculations of say an austnitic SS tower/column of considerable dimensions.

Am I missing on something?

Warm regards,

Jehan17718

The data in built (data base) of a software is not important.

More than that the actual thickness itself may vary from thickness shown in drawing or design report slightly. To cover such uncertainties, care is taken in detailed seismic analysis by broadening the floor response spectra by -15% to +15%.

Such an analysis is seldom done in conventional components (mostly in critical applications such as nuclear) and the conventional approach will not cover for variations in thickness/ density. Earlier days when factor of safety was more, we can argue that the uncertainties are covered by design factors. However, now design factors are reduced and I feel one should do sensitivity analysis by changing input by 5% or maximum10%.

You may find not sensitive in many cases

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R.SRINIVASAN
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Head, Design and Engineering
PED,ISGEC,
YAMUNANAGAR
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