Contact US

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

Inertia tensor of an assembly for dynamic analysis-Inconsistency from Solidworks

Inertia tensor of an assembly for dynamic analysis-Inconsistency from Solidworks

Inertia tensor of an assembly for dynamic analysis-Inconsistency from Solidworks

Hello for all.
When I calculate the mass property of an assembly, solidworks calculates inconsistent answers.
The assembly is composed by sub-assemblies and components.
The answer of the inertia tensor is inconsistent because of the following reasons:
1) The eigenvalues of the inertia tensor around the center of mass obtained from mathcad using the tensor supplied by solidworks are not equal of the principal moments of inertia given by solidworks;
2) The principal directions of the inertia tensor forms a rotation matrix (arranged by columns). The following mathmatical rule applies: RT*(inertia tensor)*R must result in a diagonal tensor, where RT is the transpose of the rotation matrix.The resulting diagonal corresponds to the principals moments of inertia. This rule fails when checked with the values supplied by solidworks;

I also performed the same checks with Pro-engineer and everything works according to the mathmatical rules in the same model.

Have anyone faced similar problems?

Many thanks in advance.

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