Steel-fiber-reinforced concrete is mainly used nowadays for industrial floors or hall floors, foundation plates with low loads, basement walls, and basement floors. Since the publication in 2010 of the first guideline about steel-fiber-reinforced concrete by the German Committee for Reinforced Concrete (DAfStb), a structural engineer can use standards for the design of the steel fiber-reinforced concrete composite material, which makes the use of fiber-reinforced concrete increasingly popular in construction. This article explains the individual material parameters of steel-fiber-reinforced concrete and how to deal with these material parameters in the FEM program RFEM.
KB 001601 | Determining Material Properties of Steel-Fiber-Reinforced Concrete and Their Application in RFEM
Do you have individual column sections and angled wall geometries, and need punching shear design for them?
No problem. In RFEM 6, you can perform punching shear design not only for rectangular and circular sections, but for any cross-section shape.
For a response spectrum analysis of building models, you can display the sensitivity coefficients for the horizontal directions by story.
These key figures allow you to interpret the sensitivity to stability effects.
The modal relevance factor (MRF) can help you to assess to which extent specific elements participate in a specific mode shape. The calculation is based on the relative elastic deformation energy of each individual member.
The MRF can be used to distinguish between local and global mode shapes. If multiple individual members show significant MRF (for example, > 20%), the instability of the entire structure or a substructure is very likely. On the other hand, if the sum of all MRFs for an eigenmode is around 100%, a local stability phenomenon (for example, buckling of a single bar) can be expected.
Furthermore, the MRF can be used to determine critical loads and equivalent buckling lengths of certain members (for example, for stability design). Mode shapes for which a specific member has small MRF values (for example, < 20%) can be neglected in this context.
The MRF is displayed by mode shape in the result table under Stability Analysis → Results by Members → Effective Lengths and Critical Loads.
You can use the "Plate Cut" component to cut plates (for example, gusset plates, fin plates, and so on). There are various cutting methods available:
- Plane: The cut is performed on the closest surface to the reference plate.
- Surface: Only the intersecting parts of plates are cut.
- Bounding Box: The outermost dimension consisting of width and height is cut out of the plate as a rectangle.
- Convex Envelope: The outer hull of the cross-section is used for the plate cut. If there are fillets at the corner nodes of the cross-section, the cut is adapted to them.