RF-/LIMITS Version 5/8

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RF-/LIMITS Version 5/8

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2.1 General Data

In module window 1.1 General Data, select the load cases and combinations whose results you want to compare with the limit states. Then, you decide if you want to perform the limit check according to a standard. The European standard EN 1995-1-1 [1], the German standard DIN 1052:2008 [2] as well as DSTV DIN EN 1993-1-8 [3] including different national application documents are available.

Figure 2.2 Module window 1.1 General Data
Standard / National Annex
Figure 2.3 Selection of standard and National Annex

The partial safety factor as well as the modification factor for the chosen material are defined automatically with the selection of the national application documents of the European countries.

Use the [Edit] button to open a dialog box where you can check and, if necessary, adjust the parameters of the selected standard or National Annex (see Image 2.4).

You can also use the [Nat. Annex] button to open the Material Factors dialog box.

Figure 2.4 Dialog box Material Factors

If None is set, you can only activate a user-defined partial safety factor γM in this dialog box.

Factor Category

This dialog section offers various timber materials for selection. The entries in the list differ according to the selected standard and annex.

Use the button [Include unassigned] to also display categories which are not used.

Partial Safety Factor / Modification Factor

The two dialog sections show the partial safety and modification factors of the service classes which apply to the selected material and the corresponding design situations.

For example, there is no service class 3 possible for oriented strand boards (OSB): The column is grayed out in this case.

Create Design Value

The strengths that are contrasted with the stresses are reduced by default as follows, depending on the class (LDC) defined in module window 1.3 Load Duration Class:


Equation 2.1 Creation of design value by editing a limit (reduction of strength)

Use the options to decide if the strengths are raised to a design level (Editing a limit, see Equation 2.1) or if the actions are increased. If the design value is increased by editing a force, Equation 2.1 is inverted:


Equation 2.2 Creation of design value by editing a force (increase of action)

If you want to define the factors and coefficients by user-defined specifications, you have to create a standard first by clicking the button. Then, you can set the parameters individually for that standard.

Existing Load Cases and Combinations

This column lists all load cases, load combinations, and result combinations that have been created in RFEM or RSTAB.

To transfer selected entries to the [Selected for Design] list on the right, click the button. Alternatively, you can double-click the entries. To transfer the entire list to the right, use the button.

As common for Windows applications, selecting several load cases is possible by clicking them one by one while holding down the [Ctrl] key. Thus, you can transfer several load cases at the same time.

If a load case's number is marked in red, you cannot design it: It indicates a load case without load data, or a load case that contains imperfections. A warning appears if you try to transfer it.

Below the list, several filter options are available. They help you assign the entries sorted by load case, load combination, or action category. The buttons have the following functions:

Table 2.1 Buttons in module window 1.1 General Data

Selects all load cases in the list

Inverts selection of load cases

Selected for Limit Checks

The column on the right lists the load cases as well as the load and result combinations that have been selected for the design. To remove selected items from the list, click or double-click the entries. To empty the entire list, click .

You can assign the load cases as well as the load and result combinations to the following design situations:

  • Persistent and Transient
  • Accidental

This classification controls the partial factors γM that are included in the determination of the resistances (see Equation 2.1).

To change the design situation, use the list which you can access by clicking the button at the end of the text box.

For a multiple selection, press the [Ctrl] key and click the corresponding entries. Thus, you can change several entries at once.

[1] Eurocode 5: Design of timber structures - Part 1-1: General - Common rules and rules for buildings; EN 1995-1-1:2010-12
[2] DIN 1052:2008-12: Design of timber structures - General rules and rules for buildings. Beuth Verlag GmbH, Berlin, 2008.
[3] EN 1993-1-8 (2005): Eurocode 3: Design of steel structures - Part 1-8: Design of joints [Authority: The European Union Per Regulation 305/2011, Directive 98/34/EC, Directive 2004/18/EC]