ProENGINEER enables its users to create new materials and set multiple properties for them, for example like density, Poisson's ratio, and hardness. But some of these properties are fairly obscure, such as mechanisms damping, tensile strength, coefficient of thermal expansion, and numerous other values. Tier units are also strange, mechanism's damping is expressed in sec/in? Doesn't that sound like the inverse of velocity? And is lbm/(in sec^2) really a measurement of pressure? How is it related to kPa or psi? If anyone can help me with a website with all these values, or can even slightly explain what exactly all this means, I'd greatly appreciate it. Thank you!!
lbm is not a unit of force, which you need for pressure. it looks weird because it's translated from mass to force. Example in metric:
Newton is (kilogram * meter) / second square. So to express unit of pressure with unit of mass you would have (Kg*m/sec^2)/mm^2
Meter / milimeter square would reduce to a numerical factor 10^6 / mm, so you end up with (Kg*/sec^2)/mm which equals to Kg/mm*sec^2, disregarding the numerical factor of 10^6.
This is the reason some of these units look weird.
BTW, when creating new materials, you do not have to insert values you don't need. Sometimes I only use density field, but mostly density, poisson's ratio, modulus of elasticity and tensile.
Hope this helped.
Dampening unit of sec / in would be an inverse of velocity.
lbm/(in*sec^2) is derived from lbm * acceleration of gravity / surface area . Units are: lbm * (in/sec^2) / in^2 which is equal to lbm*in / in^2 * sec^2.
in / in^2 = 1/in so we get lbm/(in*sec^2)
P.S. You can make it easier on yourself by changing units in drop down box, it will allow you to input these values in any unit you like.