×
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

How to handle components that dont play any role in structural behaviour?

How to handle components that dont play any role in structural behaviour?

How to handle components that dont play any role in structural behaviour?

(OP)
Hey guys,

I have the structural part of my model already finished, however that is not enough because I need to include all the other components that will influence the dynamics of the whole model. I want to have the influence, for example, of the weight and inertia of my motor, however I dont want to have a solid instance cause my model is already huge and I'm trying to reduced the number of DOF as much as possible.
So I wonder what the alternative is. I am afraid that with discrete rigid elements the whole structure becomes stiffer than it really is.

So my main question resumes to this: I want to include the inertias and weights of the components and I dont know how should I connect them to the main structure, without influencing the strcuture stiffness.
(I hope I was clear enough)

I'm little confused with this, so If someone could give me some ideas I'd appreciate.

Thanks in advance,
PTsal

RE: How to handle components that dont play any role in structural behaviour?

Add point mass & inertia, and couple them with your existing parts.

interaction->special->inertia

RE: How to handle components that dont play any role in structural behaviour?

(OP)
I already thought of doing it that way, however I don't think that is the right way to do it.

For example, if I have four support points for the point mass & inertia and if I couple the point to those 4 points, it is as if I have a rigid connection between the four support points, and I dont want that.

Do you know any alternative to that?

RE: How to handle components that dont play any role in structural behaviour?

Use connectors to connect the mass, and give them an elastic behavior (with possible damping). Alternatively, you could use substructuring to represent your engine by one 'mega-element', see e.g. 3.2.2 Substructure analysis of a pick-up truck model. I've only used it in static sims, but manual says you can use in dynamic also.

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