×
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

Modulus of Elasticity

Modulus of Elasticity

Modulus of Elasticity

(OP)
Hi,

Two Questions;

I am preparing to do a FEA model to determine the properties of a structure in vibration (natural freq, mode shapes etc).

Q.1 Should I specify the young's modulus of the material as that of the material under static conditions OR as that under dynamic conditions?? If you could point me in the direction of any literature I would greatly appreciate it.

Q.2 Say I am modelling an RC slab using 2-d elements. I am then applying material properties to these elements. As I have a composite material (concrete and embedded steel), how is this reflected in the Youngs Moduls which I specify for the planar element. Again if you could point me in the direction of any literature it would be a great help.


Best Regards,

Flipper.  

RE: Modulus of Elasticity

1 dynamic

2 any decent structures texbook. basically work out the equivalent bending stiffness for a uniform material with the same average density. Do that by working out the neutral axis of the original section and plotting the strain through it.

3 I suggest you get the results checked very carefully. Dynamic analysis is easier in some ways than statics, but the questions you are asking seem rather fundamental.

Cheers

Greg Locock

I rarely exceed 1.79 x 10^12 furlongs per fortnight

RE: Modulus of Elasticity

Use E valuse as 5000sqrt(fck) MPa.
It is OK if you will ignore steel.

RE: Modulus of Elasticity

The previous poster structurallyyours will need to provide a great deal of justification for his comments.

Cheers

Greg Locock

I rarely exceed 1.79 x 10^12 furlongs per fortnight

RE: Modulus of Elasticity

You can get some guidance in ACI 349. Similar value of Young's modulus for reinforced concrete is specified in ASCE 4-98 for use in seismic analysis. There are also some guidelines there on whether you need to consider cracked or uncracked sections which affect member's stiffnes.

RE: Modulus of Elasticity

In part your answer depends on the completeness finite element model being used.



 

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