if I use cm for length, what should I use for density?

[abaqusforum]

I don't have lots of experience in dynamic analysis. if I use cm for length in dynamic analysis, what should I use for mass? Youngs modulus is kgf/(cm^2)?
Thanks!

 

[IRstuff]

Why would it make any difference, other than the scale of the result? The only concern should be using consistent units throughout any analysis.

TTFN

FAQ731-376

 

[abaqusforum]

what's the density unit consistent with cm?

 

[abaqusforum]

I have a model generated by somebody else in cm. those density of steel is about 10^(-5). I want to convert to meters.

 

[hacksaw]

okay

density of steel is roughly 7.85(-3) kg/cm3 so in SI it is

7.85x(100 cm/1m)^3=7.85(+3) Kg/m3

whereas in the conv english units

steel density is 0.283 lbf/in3 but in
mass units it is 0.733(-5) lbm/in3 more or less

so it would appear that the originator of your model is using mixed units

 

[IRstuff]

Why can't you ask the perpetrator? You haven't exactly given a complete number, yet, you're expecting a cogent answer.

What is the exact number?

the density of low-carbon steel is:

7.87E-6 kg/cm^3
~ 10E-5 kg/cm^3

TTFN

FAQ731-376

 

[Twoballcane]

I think the first question is what units are "you" working in for your project? SI or English?

Tobalcane
"If you avoid failure, you also avoid success."

 

[Denial]

Whatever units you use, make sure that the formula F=ma applies.

 

[Twoballcane]

yup and in english F=(m/gc)a...

Tobalcane
"If you avoid failure, you also avoid success."

 

[abaqusforum]

Thanks Denial. The problem has been solved as you suggested!