Rubber Expansion Joints

How does one model rubber Expansion joints in CAESAR.
I have Axial, Lateral and Bending Stiffness available.
Thanks

That depends on what version of CAESAR II you have.

Version 4.40 and earlier
You must use a "zero length" element, which means you leave all three delta fields blank. Then, check the expansion joint checkbox. On the resulting auxiliary dialog, you must fill in ALL stiffnesses, including torsional. If you don't have a value for the torsional stiffness, ask the vendor. If this doesn't work, use a rigid stiffness (1E12) and then review the analysis output to ensure you don't have a large torsional moment acting on the joint.

Version 4.50 and later
You can use the "zero length" element method as described above, or use a finite length element. Again check the expansion joint checkbox, and on the resulting auxiliary dialog, fill in ALL stiffnesses, including torsional.

For additional information on expansion joint stiffnesses and their relationships, please see the article in the May 1993 issue of COADE's Mechanical Engineering News. If you don't have a hard copy of this issue, it can be found on this web site by following the link at the left.