×
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

Can ABAQUS do base excitation vibration?

Can ABAQUS do base excitation vibration?

Can ABAQUS do base excitation vibration?

(OP)
Hello All,

Has anyone here experience using ABAQUS to solve base excitation analysis? I'd like to use PSD data as the input excitation to smaller structures on engines which I usually model as a base excitation (i.e. vibration comes through the structure constraints). Can ABAQUS do this? If so what are the basic setup steps?

TIA,

George

RE: Can ABAQUS do base excitation vibration?

Yes, ABAQUS can do this quite well. Use 2 steps.
Step 1 - a normal modes analysis.
Step 2 -
*psd-definition,name=base,type=base,g=9.807
*step
*random response
*modal damping,structural
*base motion,dof=?,lcase=?
*correlation,psd=base,type=uncorrelated

The above keywords should be all you require.

Incidentally you can take this a step further and use the psd stresses obtained to estimate a fatigue life for the loading cycle input as the psd curve.(using method defined by Bishop+Sherrat. Dirlik then produced an equation which estimates the probability density of rainflow ranges from the psd response. From this curve the fraction of the total test period at a specific stress range can be estimated, and combining this with Miners rule the damage and hence life can be calculated using an S-N curve derived from material constants.) This sounds horrendous but the maths is simple and well within spreadsheet capability.

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