As part of my master's thesis, I am dealing with the static recalculation of a historic vaulted bridge (Moabiter Bridge, Berlin) using RFEM 6.
For the modeling, I refer to a research report that describes a "simplified micromodel" as a 2D plate model.
My basic setup in RFEM 6 (2D, surface thickness 100 cm) is as follows:
-The individual masonry stones are drawn as 2D surfaces and defined as linear-elastic.
-The infill (triangular sections of rammed concrete) is also drawn as a linear-elastic 2D surface directly above the arch.
According to the research report, the following conditions must be met:
- The joints between the stones should be modeled as nonlinear contact elements.
- The material law requires:
- No tensile strength.
- Compressive strength of 15 MN/m². Upon reaching this value, the joint should behave ideally plastically (bilinear material law / hinge formation).
- Pure friction law with a friction coefficient of 0.8.
The interaction between the arch and the infill: Here, too, no rigid connection should exist. The contact area should be able to transfer compression and friction but must be able to detach under tensile stresses (e.g., when the arch deforms under traffic load).
My questions to you: How do I best and most numerically stably implement these two requirements (mortar joints and arch-concrete contact) in RFEM 6? Which functions (e.g., line releases, line hinges, or other contact elements) and which detailed settings would you recommend for this purpose?
