Why is an opening not taken into account when determining the punching load due to shear forces in the critical perimeter?


When determining the punching load from shear forces in the critical perimeter, a continuous perimeter is applied.

If an intermittent perimeter was to be used when determining the punching load, the load component (along the intermittent length) might not be considered. This would be the case, for example, if you have only defined the opening in RF‑PUNCH Pro, but not in the RFEM model. In the RFEM model, the shear force would be generated by using the continuous cross-section. If the component were neglected, there would be too small punching load determined.

Therefore, the intermittent control perimeter is always applied in RF‑PUNCH Pro when determining the punching load from the shear forces within the critical perimeter.

During the design (on the resistance side), the opening is considered again and the perimeter section is reduced accordingly.


Perimeter Opening Punching load Wall corner Wall end Punching Intermittent



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RFEM Main Program
RFEM 5.xx

Main Program

Structural engineering software for finite element analysis (FEA) of planar and spatial structural systems consisting of plates, walls, shells, members (beams), solids and contact elements

Price of First License
3,540.00 USD
RFEM Concrete Structures
RF-PUNCH Pro 5.xx

Add-on Module

Punching shear design of foundations and slabs with nodal and line supports

Price of First License
760.00 USD