Opposite Constraints in Sap2000 1

[Shell76]

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.

 

[masomenos]

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

 

[Shell76]

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.