Global 3D calculation of the global model, where the slabs are modeled as a rigid plane (diaphragm) or as a bending plate
Local 2D calculation of the individual floors
After the calculation, the results of the columns and walls from the 3D calculation and the results of the slabs from the 2D calculation are combined in a single model. This means that there is no need to switch between the 3D model and the individual 2D models of the slabs. The user only works with one model, saves valuable time, and avoids possible errors in the manual data exchange between the 3D model and the individual 2D ceiling models.
The vertical surfaces in the model can be divided into shear walls and opening lintels. The program automatically generates internal result members from these wall objects, so they can be designed as members according to any standard in the Concrete Design add-on.
In the Timber Design add-on for RFEM, you can design members as well as surfaces according to Eurocode 5, SIA 265 (Swiss standard), CSA O86 (Canadian standard), or ANSI/AWC NDS (American standard); for example, cross-laminated timber, glued-laminated timber, softwood, mass timber, and so on.
Have you activated the Building Model add-on? Very good! This allows you to display the center of rigidity in tabular and graphical form. Use it for your dynamic analysis, for example.
Compared to the RF‑/STEEL add-on module (RFEM 5 / RSTAB 8), the following new features have been added to the Stress-Strain Analysis add-on for RFEM 6 / RSTAB 9:
Treatment of members, surfaces, solids, welds (line welded joints between two and three surfaces with subsequent stress design)
Output of stresses, stress ratios, stress ranges, and strains
Limit stress depending on the assigned material or a user-defined input
Individual specification of the results to be calculated through freely assignable setting types
Non-modal result details with prepared formula display and additional result display on the cross-section level of members
After you have completed the design, the program takes care of clearly arranged results. Thus, the program shows you the resulting maximum stresses and stress ratios sorted by section, member/surface, solid, member set, x-location, and so on. In addition to the tabular result values, the add-on shows you the corresponding cross-section graphic with stress points, stress diagram, and values as well. You can relate the design ratio to any kind of stress type. The current location is highlighted in the RFEM/RSTAB model.
In addition to the tabular evaluation, the program offers you even more. You can also graphically check the stresses and design ratios on the RFEM/RSTAB model. It is possible for you to adjust the colors and values individually.
The display of result diagrams of a member or set of members enables you a targeted evaluation. For each design location, you can open the respective dialog box to check the design-relevant section properties and stress components of any stress point. Finally, you have the option of printing the corresponding graphic, including all design details.
For timber surfaces with the "Constant" thickness type, the crack factor kcr and thus the negative influence of cracks on the shear capacity is taken into account.
As you probably know, the design checks for the selected members are carried out, taking into account the defined charring time. All necessary reduction factors and coefficients are stored accordingly in the program and are taken into account when determining the load-bearing capacity. That saves you a lot of work.
The effective lengths for the equivalent member design are taken directly from the strength entries. You do not have to enter them again.
After completing the design, the program presents the fire resistance design checks clearly and with all result details. This allows you to follow the results completely transparently. The results also contain all the required parameters, so you can determine the component temperature at the design time.
In addition to all these features, the program allows you to integrate all result tables and graphics, including the ultimate and serviceability limit state results,into the global printout report of RFEM/RSTAB as a part of the steel design results.
In RFEM and RSTAB, you can design members with the "Laminated Veneer Lumber" material type. The following manufacturers are available:
Pollmeier (Baubuche)
Metsä (Kerto LVL)
STEICO
Stora Enso
In the ultimate configuration, you can consider strength coefficients for increasing the strengths. The coefficients reducing the strengths are automatically taken into account regardless of this. Try it now!
You can graphically evaluate result sections for the timber surface design. This can be done in the RFEM graphic as well as in the result history window. The sections can be placed at any location in order to evaluate the design results in detail.
Design of tension, compression, bending, shear, torsion, and combined internal forces
Consideration of a notch
Design of compression perpendicular to the grain on the end and intermediate supports with (EC 5) and without reinforcement elements (fully threaded screws)
Optional shear force reduction at the support
Design of curved and tapered members
Consideration of higher strengths for similar components that are close together (factor ksys according to EN 1995‑1‑1, 6.6(1)‑(3))
Option to increase shear resistance for softwood timber according to DIN EN 1995‑1‑1:NA NDP to 6.1.7(2)
Stability analyses for flexural buckling, torsional buckling, and flexural-torsional buckling under compression
Import of the effective lengths from the calculation using the Structure Stability add-on
Graphical input and check of the defined nodal supports and effective lengths for stability analysis
Determination of the equivalent member lengths for tapered members
Consideration of the lateral-torsional bracing position
Lateral-torsional buckling analysis of the structural components subjected to moment loading
Depending on the standard, a choice between user-defined input of Mcr, analytical method from the standard, and use of internal eigenvalue solver
Consideration of a shear panel and a rotational restraint when using the eigenvalue solver
Graphical display of a mode shape if the eigenvalue solver was used
Stability analysis of structural components with the combined compression and bending stress, depending on the design standard
Comprehensible calculation of all necessary coefficients, such as the factors for considering moment distribution or interaction factors
Alternative consideration of all effects for the stability analysis when determining internal forces in RFEM/RSTAB (second-order analysis, imperfections, stiffness reduction, possibly in combination with the Torsional Warping (7 DOF) add-on)
Your options in timber design are diverse. You can consider cut-to-grain angles, transverse tension stresses, and volume-dependent radii of curvature for tapered and curved members. To design the area of the grain cut, the strength is adjusted accordingly in the case of bending tension or bending pressure. In order to also allow you to perform a stability analysis with the equivalent member method, the height to determine the effective and lateral-torsional buckling lengths is set at a distance of 0.65 × h to the actual design point.
A library for cross-laminated timber panels is implemented in RFEM, from which you can import the manufacturer's layer structures (for example, Binderholz, KLH, Piveteaubois, Södra, Züblin Timber, Schilliger, Stora Enso). In addition to the layer thicknesses and materials, there is also the information about stiffness reductions and the narrow side bonding.
Compared to the RF‑/TIMBER Pro add-on module (RFEM 5 / RSTAB 8), the following new features have been added to the Timber Design add-on for RFEM 6 / RSTAB 9:
In addition to Eurocode 5, other international standards are integrated (SIA 265, ANSI/AWC NDS, CSA O86, GB 50005)
Design of compression perpendicular to grain (support pressure)
Implementation of eigenvalue solver for determining the critical moment for lateral-torsional buckling (EC 5 only)
Definition of different effective lengths for design at normal temperature and fire resistance design
Evaluation of stresses via unit stresses (FEA)
Optimized stability analyses for tapered members
Unification of the materials for all national annexes (only one "EN" standard is now available in the material library for a better overview)
Display of cross-section weakenings directly in the rendering
Output of the used design check formulas (including a reference to the used equation from the standard)
Here you have a free choice. You can perform the support pressure design at any point for the loading in the y- and z-directions of a cross-section. You are free to differentiate between inner and outer supports. A factor kc,90 for the pressure perpendicular to the grain can be user-defined (for example, 1.75 for glued-laminated timber). If allowed, the support length is increased automatically according to the standard specifications. This allows you to achieve a more efficient design with minimum effort.
Using the "Load Transfer Only" story type, you can consider slabs without stiffness effects in and out of the plane in the Building Model add-on. This element type collects the loads on the slab and transfers them to the supporting elements of a 3D model. Thus, you can simulate secondary components, such as grillage and similar load distribution elements, without any further effect in the 3D model.
RFEM/RSTAB also provides a range of functions for the case of a fire. The program allows for the automatic generation of load and result combinations for the accidental design situation of fire design. The members to be designed with the corresponding internal forces are imported directly from RFEM/RSTAB. Also, all information about the material and cross-section is stored. You don't need to do anything else.
You only define the parameters relevant for the fire resistance design by assigning a fire resistance configuration to the members and surfaces to be designed. Moreover, you can also make further detailed settings, such as the definition of the fire exposure on one side up to all sides.