In the case of a nonlinear calculation for the serviceability limit state designs, I get implausibly large values for the crack width and deformation in the RF‑CONCRETE modules (see Figure 01). What is the cause and how can I fix the problem?

Please note that in the case of a nonlinear calculation, the reinforcement is not increased automatically. The nonlinear calculation is based on the reinforcement already provided. This provided reinforcement can result from the ultimate limit state designs or from the defined basic reinforcement, for example. The reinforcement applied to the SLS designs can be displayed graphically (see Figure 02).

Problem Cause:

If there is no reinforcement resulting from the ULS or the basic reinforcement in any areas, the serviceability limit state design is carried out without the applied reinforcement, which may cause very high results, for example, of a crack width.

Problem Solution:

You should ensure that there is the reinforcement available in each area of the structure. This can be done by applying the basic reinforcement (see Figure 03).