Design of Timber Materials

When designing several members in one design case, it is sometimes difficult to recognize the governing design checks. To improve the overview and to display the relevant design checks in a compact way, you can use the filter options under the result tables. These are included in all design modules of steel, aluminum, and timber structures in RFEM and RSTAB.

With the RF-/TIMBER Pro add-on module, you can perform the vibration design known from DIN 1052 for the design according to EN 1995-1-1. In this design, the deflection under permanent and quasi-permanent action at the ideal one‑span beam may not exceed the limit value (6 mm according to DIN 1052). If you consider the relation between the natural frequency and the deflection for a hinged single-span beam subjected to a constant distributed load, the 6 mm limit value results in a minimum natural frequency of about 7.2 Hz.

In the course of a reasonable pre-dimensioning of cross-sections, you can optimize the cross-sections of the corresponding section series in the RF‑/TIMBER Pro add-on module.

After the calculation, the module displays results in clearly arranged result tables. Each intermediate value is listed, making the design checks transparent. The results are sorted by load case, cross-section, set of members, and members.

If the analysis fails, the affected cross-sections can be modified in an optimization process. It is also possible to transfer the optimized cross-sections to RFEM/RSTAB for a new calculation.

The design ratio is represented with different colors in the RFEM/RSTAB model. This way, you can quickly recognize critical or oversized areas of the cross-section. Furthermore, result diagrams displayed on the member or set of members ensure targeted evaluation.

In addition to the input and result data, including design details displayed in tables, you can add all graphics into the printout report. This way, comprehensible and clearly arranged documentation is guaranteed.

The design analyzes tension and compression along the grain, bending, bending and tension or compression, and shear due to shear force with and without torsion. Designs proceed at the level of design stress values.

The design of structural components at risk of buckling or lateral buckling is performed according to the Equivalent Member Method and considers the systematic axial compression, bending with and without compression force as well as bending and tension. The deflection of inner spans and cantilevers is determined in characteristic and quasi-permanent design situations.

Separate design cases allow for a flexible and stability analysis of members, sets of members, and loads. In the case of tapered members, the cut-to-grain angle is considered in the bending tension and bending compression area. If there is a ridge defined, the module performs the ridge design additionally.

After opening the add-on module, it is necessary to select the members/sets of members, load cases, load or result combinations for the ultimate limit state, serviceability limit state, and fire resistance design. The materials from RFEM/RSTAB are preset and can be adjusted in RF-/TIMBER Pro. Material properties listed in the respective standard are included in the material library.

After the cross-section check, the module determines the load duration classes (LDC) and the service classes (SECL). It is possible to assign them to the selected load cases and members.

Combined cross-sections may consist of various materials. The RF-/TIMBER Pro add-on module performs designs considering the shifted neutral axis (in the case of semi-rigid cross-sections). The deformation analysis requires the reference lengths of the relevant members and sets of members. Furthermore, you can define a specific direction of deflection, precamber and the beam type.