How to model guide bearing for bridge in SAP2000?

[jackyyau]

I am building a 3-D SAP2000 bridge model. The bridge has 2 guided bearings and 2 free bearings.
I tried to model the bearings by the following two ways:

1. CONSTRAINT - EQUAL (for joints at the same coordinates)
2. FRAME RELEASE (for end frame release)

However, both ways do not produce the anticipated results.

Please HELP!

 

[Dinosaur]

I recommend a bi-pod under the girder of two truss members. The girder will only be able to translate in a direction normal to the line of the bi-pod. As long as the displacements are small, the error will not be important. If you need stiffness, as in an elastomeric pad application, you will need to use another dummy element or a support spring constant. I don't know much about SAP. I have used only GTStrudle, ANSYS and STAAD. A bi-pod will produce a giuded bearing in any FE program. Good Luck