a wrong unit system used in verification test 201? 1

[tsukuba]

Hi,
VM201 is the Verification Test of Rubber Cylinder Pressed Between Two Plates.
I noticed the VM201 used a strange unit system where length unit is m, force unit is N but Young's modulus unit is MPa.

/VERIFY,VM201
...
R = 0.2 ! RADIUS OF CYLINDER
!!no unit is given in its list, but meter unit is used in the description of this verification example.
...
MP,EX,1,2.82 ! YOUNG'S MODULUS [MPA]
MP,NUXY,1,0.49967 ! POISSON'S RATIO

Is there anything wrong with the unit system used in VM201?

Thanks,

Tsukuba

 

[Drej]

No, there is nothing wrong. The stresses will be in MPa, the units of force are Newtons. This is a displacement controlled analysis, if it was force controlled, you could use any particular order of modulus (2.82 or 2.82E9 etc.) and get the same stress (but the displacement would change).

 

[tsukuba]

Thanks Drej,

I am sorry I cannot get what you said. I think the key point is the displacement controlled analysis. I want to know why the units of force are Newtons in a displacement controlled analysis if the stresses are in MPa.

In fact, I think the units of force are MegNewtons, because meters, MegNewtons and MPa are consistent unit system. If the force are in Newtons, then the lengths should be in millimeters.