×
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

Time lag in micromechanical viscoelastic model

Time lag in micromechanical viscoelastic model

Time lag in micromechanical viscoelastic model

(OP)
Hi,

I have been trying to develop a micromechanical model for a composite material (asphalt concrete) in ABAQUS. There are two layers in my model, stone (elastic) and asphalt-mastic (viscoelastic). For the viscoelastic model I used Prony series, below are my laboratory determined coefficients for gi, ki and tau, respectively: Temperature model parameters are , C1 C2 ref. temp = 40C
51.60 524.32

0.680145196    0.680145196    0.006491248
0.140528279    0.140528279    0.006490248
0.128376203    0.128376203    0.077028183
0.027891741    0.027891741    1.101221013
0.005270496    0.005270496    0.2

THE PROBLEM IS when I run the model for my composite material, I do not get any time lag between stress and strain although there must be some according to our lab test results related to the viscoelastic behavior of asphalt-mastic. Does anybody have an idea why I dont get time lag? I am checking the time lag by plotting Displacement vs. Total force (load is applied by using a displacement boundary condition since the test I am trying to simulate is strain controlled)

I look forward to hearing from you guys!!!

Thanks

Tony

RE: Time lag in micromechanical viscoelastic model

Make sure the analysis type is VISCO not STATIC.

Nagi Elabbasi
www.veryst.com

RE: Time lag in micromechanical viscoelastic model

(OP)
Hi Ellabbasi,

I used VISCO.

RE: Time lag in micromechanical viscoelastic model

How does the applied displacement vary with time? If it is applied too fast or too slow (what constitutes fast and slow depends on your viscoelastic constants) then there would be no significant viscoelastic effects and therefore no time lag.

Nagi Elabbasi
www.veryst.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