Question: How to modify the relaxation curve to CEB-FIP 90?

Answer: At Analyzer \ Properties \ Time Functions, modify the currently assigned C&S, Rel. Variables.

The time dependency of specific material properties can be considered in the OpenBridge Designer analysis. In RM Bridge, these time dependencies are defined by sets of variables. The default database has variables for creep, shrinkage, and relaxation definitions prepared for each property group. For example, by country, and by each considered Code the property group will contain one set of time-dependent functions. At RM Bridge \ Analyzer \ Properties \ Time Functions, a plot of the Creep & Shrinkage variation, elasticity modulus for any defined concrete element, and relaxation for pre-stressed steel can also be viewed here. The other option, C+S calculation, activates internal formulas for concrete creep, shrinkage, and steel relaxation.

      

As highlighted in red in the second and third screenshots above, in case the project requires assigning different time-dependent material properties to a material, the user can either:

1. Double-click over the definition in the Top table and directly select the variables from the drop-down menu of variables.
2. Click on Modify at the Top table, and in the Group Material, assign each variable from the drop-down menu.

Hint: If the material has not yet been imported into the current project database, an alert will appear, as shown in the third picture above. To previously import the default material properties, check the step-by-step instructions at the link below:

https://bentleysystems.service-now.com/community?id=kb_article_view&sysparm_article=KB0039453

Note: If the curve does not exist, does not plot, or is incorrect, there are four possibilities and their corrections: