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!

*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

Direct frequency response analysis

Direct frequency response analysis

Direct frequency response analysis

Dear Users,

I have to do a response analysis of a certain construction (NX Siemens, Nastran solver 108, Direct frequency response analysis)

How do you define such excitation:
Excitation: 9.81 m/s² ≈1 g
Frequency Range: 10…..500 Hz
Sine-Sweep: 0.5 octave / min

Regards, Peter

RE: Direct frequency response analysis

I don't know if it is your question, but there can be subleties involved when we try to give a math expression for a swept sin. In particular, see this thread: thread384-29248: Swept sine spectrum puzzler

The easy bottom line to that wandering thread - try plotting your proposed analytical expression (like op of linked thread did) to see if the apparent frequency matches what you intended or a factor of 2 different.

(2B)+(2B)' ?

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! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close