As noted in the ISM Revit Plugin release notes, if you have installed Revit 2023 then the Analytical Model options may not be visible anywhere in the Revit interface. Without this interface the physical members from Revit will be exported to ISM with the Load Resistance property set to None. Most of the analytical products including Ram Elements and RAM Structural system filter out such objects and do not import them.
In order to reactivate the analytical model and define the necessary properties, follow these steps.
First go to File - Options - User Interface and turn on Structure Tab and Tools
Then we have the Analytical Automation button noted in the release notes:
Clicking it displays this window:
Select all members and then Run:
Then the analytical option is available and we are ready to set those members to a type:
After that we can send the ism and is sent as the type we selected. In this case Gravity:
And this is now successfully imported into RAM SS and Elements:
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