×
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

What modulus to use - TANGENT OR SEECANT modulus ?

What modulus to use - TANGENT OR SEECANT modulus ?

What modulus to use - TANGENT OR SEECANT modulus ?

(OP)
Is there any guidelines on when the tangent and when the secant modulus should be used in modeling ?  I am modeling fabric material so the behavior is non-linear but several people at my office think tangent modulus should be used whereas others think secant modulus should be used in modeling behavior.

I searched the web and nothing provides direction on what is more suitable for FEA non-linear fabric material behavior.

Thanks for any input.

Regards -
  

RE: What modulus to use - TANGENT OR SEECANT modulus ?

What type of analysis are you running (stress, vibration, bucking, ...), and what type of results do you want to obtain (stress, displacement, modes, ....)?

Is this bare fabric? composite?

RE: What modulus to use - TANGENT OR SEECANT modulus ?

(OP)
I am running a static stress analysis interested in stresses with a side interest in displacements.  The element is membrane type - i.e. no bending stress.  Material is  not modeled as a composite - it is modeled as an Orthotropic type.

RE: What modulus to use - TANGENT OR SEECANT modulus ?

I don't think you should use either "modulus". For a nonlinear analysis you should input the stress-strain curve for the material.  If you want to predict failure you will need to select a failure criteria and input the appropriate material strength parameters.

RE: What modulus to use - TANGENT OR SEECANT modulus ?

I am agree with SWComposites, I think you should use a combination of elastic and plastic material properties.

Regards,

Mohammad Shahbazi
www.OmranAfzar.com

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