Answer:
RFEM has an extensive material and cross-section library. It was deliberately avoided to implement the entire library as a Grasshopper component, since it would require a component with thousands of entries and a large amount of data.
You can create your own component with the required materials and cross-sections using a value list. To do this, copy the complete Dlubal material and cross-section names into a Value List.
You can then save it as a "User Object" and used it as a fixed component in Grasshopper.
The FAQ video shows an example of creating a material and a cross-section component for RFEM 6.
