×
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

Opposite Constraints in Sap2000

Opposite Constraints in Sap2000

Opposite Constraints in Sap2000

(OP)
I am trying to model a symmetic structure, I know how to model the equal and in the same direction DOF but what about the opposite one. For example if XZ is my plane of symmetry, I would need the Uy(displacement in the y direction ) to be opposite, how can I define that.
Thanks in advance for your help, it is a great forum by the way.

RE: Opposite Constraints in Sap2000

If I understand your request, you want to use constraints to connect together different portions of your model in order to take advantage of symmetry without having to model the entire structure, right? Could you please post an .sdb file or a drawing of what you have, and what you are trying to do? It would make it easier to envision your request for information

RE: Opposite Constraints in Sap2000

(OP)
Thanks masomenos for your reply, it is really appreciated,
What I am asking about is a part of the sap help menue about symmetric structure, the paragraph under symmetry about a plane is read :
"For a structure that is symmetric about a plane, symmetric loading causes symmetric displacements as follows:

Forces and displacements parallel to the plane of symmetry are equal.

Forces and displacements normal to the plane of symmetry are opposite.

Moments and rotations parallel to the plane of symmetry are opposite.

Moments and rotations normal to the plane of symmetry are equal.

Consider the example of a structure that is symmetric with respect to a plane normal to the X axis and subjected to symmetric loading. One Equal Constraint and one Opposite Constraint must be defined for each pair of joints that is symmetrically located with respect to the plane. The degrees of freedom that would be specified for the Equal Constraints are UY, UZ, and RX, and for the Opposite Constraint, degrees of freedom UX, RY, and RZ. The constraint types would be switched to model the symmetric case.

Any joints on the plane of symmetry should not be constrained, but instead have their UX, RY, and RZ degrees of freedom restrained."
My question is how I can deined the opposite constraint, there is just equal constraint in sap that define equal and in the same direction DOF.
Hopefully that give you more information to answer my question.

 

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