×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Rubber FEA

Rubber FEA

Rubber FEA

(OP)
Two questions about archived thread727-53543:

1.  GSC ended the thread by saying, "Setting linear or piecewise linear elastic properties with poisson ratio > 0.495 could give fairly good results at small deformations only."  I would think that using a Poisson's ratio >= 0.49, even for small strains, leads to serious numerical errors (www.mscsoftware.com-assets-103_elast_paper.pdf, p. 42).  Has anyone besides GSC obtained reasonable FEA results for nearly incompressible materials by using a Poisson's ratio and bulk modulus (instead of Young's modulus) from small-strain linear elasticity theory?

2.  Earlier in the thread (5 jun 03) jgough said, "In this case his uniaxial tension test should suffice to provide a value for C10.  Theoretically it shouldn't matter what deformation mode he uses (as long as his material is isotropic, which it should be)...."  Since rubber's stress-strain curve is very different for compression than tension, why shouldn't the deformation mode of the uniaxial test matter when determining constants for a hyperelastic material model?

RE: Rubber FEA

EcoMan;

Re. 1: I would suggest using bulk modulus and young's modulus.
Re. 2: I couldn't agree more with your question, and think that jgough was seriously oversimplifying things...

Ron

RE: Rubber FEA

(OP)
RvL04,

FEA without material nonlinearity (and anisotropy) requires a single modulus--not bulk modulus AND Young's modulus.

I didn't mean to imply that jgough was oversimplifying things.  I'm just trying to understand.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources