Hello, I have a quote for a tied-universal expansion joint and I want to model it in Caesar II. I have an over all length, bellows material, and axial and lateral spring rates for the TUEJ as a whole. For my model, I have a TUEJ generated by the EJ modeler.

If I understand things correctly, the springs rates I get from the CAESAR II EJ modeler are for each, individual, bellows element and not the TUEJ as a whole.

Assuming I am right in thinking I need to, how can I convert the spring rates given in quote to something I can use in Caesar II?

Also, any other tips for designing/verifying expansions joints with CAESAR II would be appreciated.

Thank you!

Please ask vendor to provide Axial, Transverse and Torsional spring rates for each bellows along with detailed dimensions for the tied-universal expansion joint and accordingly, modify the default dimensions and spring rates from Caesar-II EJ modeler; so as to get similar overall lateral spring rate. To test this, prepare separate Caesar-II file for this EJ alone, keep one end anchored and apply some nominal lateral force say 1000N at the other end of EJ and check corresponding lateral deflections at free end in the output report. Overall Lateral stiffness = Lateral force / Lateral displacement.

There are different modelling methods for universal EJs, simple vs complex explained in CAESAR II Applications Guide.