Elastic foundation coefficients are calculated according to the non-linear iterative method. The module determines elastic foundation coefficients for each individual element. They are dependent on the deformation.
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.
The design of cold-formed steel members according to the AISI S100-16 / CSA S136-16 is available in RFEM 6. Design can be accessed by selecting “AISC 360” or “CSA S16” as the standard in the Steel Design Add-on. “AISI S100” or “CSA S136” is then automatically selected for the cold-formed design.
RFEM applies the Direct Strength Method (DSM) to calculate the elastic buckling load of the member. The Direct Strength Method offers two types of solutions, numerical (Finite Strip Method) and analytical (Specification). The FSM signature curve and buckling shapes can be viewed under Sections.
The calculated stresses and settlements are displayed in result windows. In addition, it is possible to evaluate the results graphically. The graphic displays the position and the layer arrangement of the soil samples to clarify the results.
The final result window shows the elastic foundation coefficients. Graphical evaluation is possible as well.
Optional consideration of stiffening elements for transversal tension
Two design types available for stiffening elements concerning transversal tension:
Constructive if required
Full absorption of tension stresses perpendicular to grain
Calculation of required number of stiffening elements for transversal tension and graphical representation of the arrangement in the beam
Simple geometry input with illustrative graphics
Convenient generation of snow loads according to EN 1991-1-3 or DIN 1055:2005, Part 5
Automatic determination of wind loads according to EN 1991-1-4 or DIN 1055:2005, Part 4
User-defined load cases and load applications
Automatic generation of all possible load combinations
Connection to MS Excel and access via COM interface
Material library for both standards
For design according to EC 5 (EN 1995), the following National Annexes are available:
DIN EN 1995-1-1/NA:2013-08 (Germany)
NBN EN 1995-1-1/ANB:2012-07 (Belgium)
DK EN 1995-1-1/NA:2011-12 (Denmark)
SFS EN 1995-1-1/NA:2007-11 (Finland)
NF EN 1995-1-1/NA:2010-05 (France)
UNI EN 1995-1-1/NA:2010-09 (Italy)
NEN EN 1995-1-1/NB:2007-11 (Netherlands)
ÖNORM B 1995-1-1:2015-06 (Austria)
PN EN 1995-1-1/NA:2010-09 (Poland)
SS EN 1995-1-1 (Sweden)
STN EN 1995-1-1/NA:2008-12 (Slovakia)
SIST EN 1995-1-1/A101:2006-03 (Slovenia)
CSN EN 1995-1-1:2007-09 (Czech Republic)
BS EN 1995-1-1/NA:2009-10 (the United Kingdom)
Extensive library of permanent loads
Allocation of a structure to service class, and specification of service class categories
Determination of design ratios, support forces, and deformations
Info icon indicating successful or failed design
Color reference scales in result tables
Direct data export to MS Excel
DXF interface for preparation production documents in CAD
Program languages: English, German, Czech, Italian, Spanish, French, Portuguese, Polish, Chinese, Dutch, and Russian
Verifiable printout report, including all required designs. Printout report available in many output languages; for example, English, German, French, Italian, Spanish, Russian, Czech, Polish, Portuguese, Chinese, and Dutch.
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!
In the RF-LAMINATE add-on module for RFEM, the design of torsional shear stresses in the superposition of net and gross cross-section values is possible. The design is performed separately in the x- and y-directions. The loads on the intersection points of cross-laminated timber panels are checked.
There are various options available for modeling a roof. Graphical representations facilitate the geometry input. Modifications are updated automatically.
In addition, it is possible to consider cross‑section weakening on supports. Optionally, you can define if the design of support pressure on the rafter side should be performed.
Permanent loads (for example, roof structure) can be entered using the comprehensive and extensible material library. Loads due to cantilevers and collars/ties can be entered separately. Generators integrated in RX-TIMBER Purlin allow for convenient generation of various wind and snow load cases. You can manually add any concentrated and distributed loads.
Load cases are displayed graphically and superimposed in automatically generated load combinations according to EC 5. For stability and serviceability limit state designs, you can change the data manually, for example, for example, for cantilevers (roof overhang), it is necessary to ignore the SLS.
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.
Did you use the eigenvalue solver of the add-on to determine the critical load factor within the stability analysis? In this case, you can then display the governing mode shape of the object to be designed as a result.
The Aluminum Design add-on provides you with further options. Here you can also design general cross-sections that are not predefined in the cross-section library. For example, create a cross-section in the RSECTION program and then import it into RFEM/RSTAB. Depending on the design standard used, you can select from various design formats. This includes, for example, the equivalent stress analysis.
With a license for RSECTION and Effective Sections, you can also perform the design checks while taking into account the effective cross-section properties according to EN 1993‑1‑5.
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 (see the Product Feature)
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 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.
The definition of soil layers is performed in a clearly arranged input window. An extensible library facilitates the selection of soil properties.
The elasticity can be defined either by the stiffness modulus or the modulus of elasticity and the Poisson's ratio. It is possible to define any number of soil layers. You can assign the layers to the building graphically or by entering the relevant coordinates.
After the calculation, the RF‑/JOINTS Timber - Steel to Timber add‑on module lists joint stiffnesses of all individual members, among other things. The following design results are displayed:
Check of minimum spacing
Load-carrying capacity of single fastener
Steel plates (bearing resistance and stress according to EC 3 and AISC)
Stress analysis with reduced timber cross‑section
Block shear failure
Total load carrying-capacity (including stiffness determination, transversal tension design according to EC 5, and others)
Graphical and numerical results of stresses and stress ratios fully integrated in RFEM
Flexible design with different layer compositions
High efficiency due to few entries required
Flexibility due to detailed setting options for basis and extent of calculations
A local overall stiffness matrix of the surface in RFEM is generated on the basis of the selected material model and the layers contained. The following material models are available:
Orthotropic
Isotropic
User-defined
Hybrid (for combinations of material models)
Option to save frequently used layer structures in a database
Determination of basic, shear, and equivalent stresses
In addition to the basic stresses, the required stresses according to DIN EN 1995-1-1 and the interaction of those stresses are available as results.
Stress analysis for structural surfaces including simple or complex shapes
Equivalent stresses calculated according to different approaches:
Shape modification hypothesis (von Mises)
Shear stress hypothesis (Tresca)
Normal stress hypothesis (Rankine)
Principal strain hypothesis (Bach)
Calculation of transversal shear stresses according to Mindlin or Kirchhoff, or user-defined specifications
Serviceability limit state design by checking surface displacements
User-defined specifications of limit deflections
Possibility to consider layer coupling
Detailed results of individual stress components and ratios in tables and graphics
Results of stresses for each layer in the model
Parts list of designed surfaces
Possible coupling of layers entirely without shear
After the calculation, the results of performed designs, including all required intermediate values, are displayed in clearly arranged result tables sorted by various criteria. Since the program displays the intermediate values in detail, the transparency of all designs is ensured. It is possible to display the distribution of internal forces for each x-location of the beam in a separate graphical window. Here, both the deformations and the individual internal forces can be displayed.
Designs with design details and selected result diagrams can be added in the printout report, providing clearly arranged documentation. The printout report can include graphics, descriptions, drawings, and more. Moreover, it is possible to select which calculation data will be covered in the printout.
It is necessary to select load cases, load combinations, and result combinations for the ultimate and the serviceability limit state design. After selecting the surfaces to be designed, you can define the relevant material model.
The structure of layers forming the basis for the stiffness calculation can vary. You can adjust the parameters defined by the selected material model according to your individual needs. The 3*3 matrix of the layers is modifiable as well. In this way completely free selection when generating the stiffnesses is provided.
The limit stresses of each layer are defined by the selected material. These values can be customized as well.
There are various options available for frame modeling. Graphical representations facilitate the geometry input. Modifications are updated automatically. Basic dimensions as well as geometrical data are entered in tables. During the input, the program checks the conditions required for the beam creation (for example, lamellas forming a curve) according to the defined standard. The most important geometry parameters are updated and displayed.
The relevant timber grade of the material can be selected from the material library. All material grades for glulam, hardwood, poplar and softwood timber specified in EN 1995-1-1 are available. Furthermore, it is possible to generate a strength class with user-defined material properties in order to extend the library. Permanent loads (for example, roof structure) can also be entered using the comprehensive and extensible material library.
Generators integrated in RX-TIMBER Purlin allow for convenient generation of various wind and snow load cases. By clicking the information buttons, the map of wind and snow zones for the relevant country is displayed. The corresponding zone can be selected with a double-click. Load cases can be checked graphically. However, you can enter load specifications manually as well. According to the generated loads, the program automatically creates combinations for the ultimate and serviceability limit states as well as for fire resistance design in the background. The generated combinations can be considered or adjusted by user-defined specifications.
Stability analyses for flexural buckling, torsional buckling, and flexural-torsional buckling under compression
Lateral-torsional buckling analysis of the structural components subjected to moment loading
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
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 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)
There are various options available for beam modeling. A roof type determines the exact purlin location for wind and snow generation.
Two beam types are available: continuous beam and purlin. If you select the continuous beam, it is possible to define several hinge conditions of the beam. If you select the purlin, it is not possible to modify hinge conditions. In this case, the calculation considers a double cross-section in the coupling zone. In addition, several coupling elements are available in the purlin settings:
Nails (prebored/not prebored)
Ring and plate connectors and bolts
Screw connection with fastening system WT from SFS intec
User-defined specification using characteristic strength
The relevant timber grade of the material can be selected from the material library. All material grades for glulam, hardwood and softwood timber specified in EC 5 are available. Furthermore, you have the option to generate a strength class with user-defined material properties and thus extend the library.A comprehensive and extensible material library can also be used for entering permanent loads (for example, roof structure).
Generators integrated in RX-TIMBER Purlin allow for convenient generation of various wind and snow load cases. By clicking the information buttons, the map of wind and snow zones for the relevant country is displayed. The corresponding zone can be selected with a double-click. Load cases can be checked graphically.
However, you can enter load specifications manually as well. According to the generated loads, the program automatically creates combinations for the ultimate and serviceability limit states as well as for fire resistance design in the background.
After the calculation, the maximum stresses, stress ratios, and displacements are displayed by load case, surface, or grid points. The design ratio can be related to any kind of stress type. The current location is highlighted by color in the RFEM model.
In addition to the result evaluation in tables, it is possible to display the stresses and stress ratios graphically in the RFEM work window. For this, you can adjust the colors and values assigned in the panel.
After the calculation, the results of performed designs, including all required intermediate values, are displayed in clearly arranged result tables sorted by various criteria. Since the program displays the intermediate values in detail, the transparency of all designs is ensured. It is possible to display the distribution of internal forces for each x-location of the beam in a separate graphical window. Here, both the deformations and the individual internal forces can be displayed.
Designs with design details and selected result diagrams can be added in the printout report, providing clearly arranged documentation. The printout report can include graphics, descriptions, drawings, and more. Moreover, it is possible to select which calculation data will be covered in the printout.
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.
First, it is necessary to select the joint type, design standard, and steel plate and dowel material. For design according to EN 1995-1-1, you can select the SFS intec dowel system WS‑T. In this case, the corresponding material is preset in accordance with the technical approval of the manufacturer.
The connected members are imported from the RFEM/RSTAB model. The add-on module automatically checks if all geometry conditions are fulfilled. Alternatively, you can define the connection manually.
The loading is also imported from RFEM/RSTAB or, in the case of manual joint definition, loads are entered. The Geometry window includes steel plate dimensions and fastener layouts.