LBM

[JReganNuTEC]

What is lbm? When I use the mass properties in Mechanical 6, the Mass is in lbm. What is lbm?

If I use Mechanical 4 with the same part it gives me the correct mass.

Thanks for your help
JJ

 

[FH]

Dear JReganNuTEC,
The lbm symbol is used for the "pounds" unit.
You can select another unit for mass properties in MDT6 in the AMMASSPROP command.

Farzad

 

[JReganNuTEC]

It's a standard "pound" ?
When I model a part that has a wieght of 4oz or 1/4lb, MDT6 gives me a mass of 3.6706lbm. In MDT4 I will get a mass of 4oz.

The model is a circle with a dia of 4.646" and a thickness of 0.390" I used a density of 15.4.

JJ

 

[JReganNuTEC]

FYI
The volume that MDT6 gives is correct so I am able to figure out the weight. density x volume = weight

Thanks JJ

 

[Adrian2]

Dear J Regan;

The lbm symbol stands for pounds mass, there is also lbf which is pounds force. The m is included to show you are talking about weight not force. In the metric system there are seperate units for mass (kilogram) and force (newton).

As you have discovered, having units with the same name for 2 different things is confusing. Dont you just love imperial measurement.

Regards Adrian