yeild strength for ABS

Hi everyone,

does anyone know the value for the yeild strength of ABS as it would be used
in SW? I can get a value from MatWeb, but I get pretty confused trying to
associate this with the values used be SW and Cosmos Express - any help
would be much appreciated!

Thanks

Lee

 

Young's modulus / 43 ... it's my bydefault value!

 

Lee,

The critical question is, what are you trying to model? If you are designing
a one-time snap and it doesn't matter if the part yields slightly you will
use a different value than if you are designing a part that is expected to
flex thousands of times. Is it a momentary stress or is it a constant load
on a part expected to be in service for 10 years? Is it an impact load? Is
the part stressed at room temperature or at some high or low temperature? Is
it a tensile stress, a compressive stress, a flexural stress? How is the
part manufactured? If it is injection molded, is there a knit line in a
highly stressed area? Which grade of ABS? What are the consequences of a
failure? The answers to the above question would probably change the value I
would use for my failure criteria by a factor of 10 or more.


Jerry Steiger
Tripod Data Systems
"take the garbage out, dear"

 

Cosmos Xpress is pretty weak at analyzing plastics. The assumptions
that it uses are:

1. Linear elastic behavior. This means it has the same modulus
regardless of strain.

2. Isotropic. This means it has the same properties in every
direction.

3. Not viscoelastic. It doesn't flow and gets its stress strain
properties from elasticitiy not entropy.

4. Not temperature dependent.

Plastics don't really meet these criteria except under a very narrow
range of circumstances.

In addition to some kind of modulus or stress strain curve you would
need the poisson's ratio for ABS.

 

in article 40f300a6$, Lee Bazalgette at