In RFEM, the oriented strand board (OSB) material is available for the USA and Canada. The material parameters are taken from the "Panel Design Specification manual".
Using the "Beam Panel" thickness type, you can model timber panel elements in 3D space. You just specify the surface geometry and the timber panel elements are generated using an internal member-surface construct, including the simulation of the connection flexibility.
A "beam panel" provides you with the following advantages:
- Single-sided and double-sided sheathing is possible
- Automatic calculation of a semi-rigid coupling
- Boarded sheathing
- Stapled sheathing
- User-defined sheathing
- Representation as a complete geometric 3D object (frame, crosstie, column, sheeting, staples), including eccentricity
- Considering openings via surface cells
- Design of the structural elements utilizing the Timber Design add-on
- Independent of material (for example, drywall with cold-formed sections and gypsum fibreboards as the sheathing)
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.
Go to Explanatory VideoThe object types listed below can be graphically assigned to the elements of the structure modeled in the program.
- Nodal supports
- Member shear panels
- Local reductions of member cross-sections
- Member transverse stiffeners
- Member longitudinal welds
- Effective lengths
- Boundary conditions
- Line supports
- Loads
- Member support
- Punching reinforcements
- Mesh refinements
- Surface reinforcements
- Surface results adjustments
- Surface support
- Service classes
- Imperfections
For stress-strain analyses, it is possible to define gray zones for nonrelevant value ranges in the result panel.
- The results of the connection design can be entered in the printout report
- When creating a new printout report, select the items added from the Steel Joints Add-on
- Use the tool 'Print Graphics to Printout Report' to insert graphics with the results of the connection, including the control panel, into the report
- Printout report contains the specifications of the connection components, design parameters, results and graphics
- 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)
- Calculation of stationary incompressible turbulent wind flow using the SimpleFOAM solver from the OpenFOAM® software package
- Numerical scheme according to the first and second order
- Turbulence models RAS k-ω and RAS k-ε
- Consideration of surface roughness depending on model zones
- Model design via VTP, STL, OBJ, and IFC files
- Operation via bidirectional interface of RFEM or RSTAB for importing model geometries with standard-based wind loads and exporting wind load cases with probe-based printout report tables
- Intuitive model changes via drag & drop and graphical adjustment assistance
- Generation of a shrink-wrap mesh envelope around the model geometry
- Consideration of environmental objects (buildings, terrain, and so on)
- Height-dependent description of the wind load (wind speed and turbulence intensity)
- Automatic meshing depending on a selected depth of detail
- Consideration of layer meshes near the model surfaces
- Parallelized calculation with optimal utilization of all processor cores of a computer
- Graphical output of the surface results on the model surfaces (surface pressure, Cp coefficients)
- Graphical output of the flow field and vector results (pressure field, velocity field, turbulence – k-ω field, and turbulence – k-ε field, velocity vectors) on Clipper/Slicer planes
- Display of 3D wind flow via animated streamline graphics
- Definition of point and line probes
- Multilingual user interface (German, English, Czech, Spanish, French, Italian, Polish, Portuguese, Russian, and Chinese)
- Calculations of several models in one batch process
- Generator for creating rotated models to simulate different wind directions
- Optional interruption and continuation of the calculation
- Individual color panel per result graphic
- Display of diagrams with separate output of results on both sides of a surface
- Output of the dimensionless wall distance y+ in the mesh inspector details for the simplified model mesh
- Determination of the shear stress on the model surface from the flow around the model
- Calculation with an alternative convergence criterion (you can select between the residual types pressure or flow resistance in the simulation parameters)
Also, on the rendered model, you see your results in a clear color display. This allows you to precisely recognize the deformation or internal forces of a member, for example. If you want to set the colors and value ranges, you can do so in the control panel.
Effective Sections is an extension of the section properties program RSECTION. Compared to the RF‑/STEEL Cold-Formed Sections add-on module for RFEM 5 / RSTAB 8, the following new features have been added to Effective Sections:
- Consideration of the effects of distortional buckling of sections via eigenvalue method
- Definition of stiffeners and buckling panels no longer necessary
- Graphical display of unit stresses
- Optional manual definition of stress points
Compared to the RF‑/ALUMINUM add-on module (RFEM 5 / RSTAB 8), the following new features have been added to the Aluminum Design add-on for RFEM 6 / RSTAB 9:
- In addition to Eurocode 9, the US standard ADM 2020 is integrated.
- Consideration of the stabilizing effect of purlins and sheets by rotational restraints and shear panels
- Graphical display of the results in the gross section
- Output of the used design check formulas (including a reference to the used equation from the standard)
- 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
- 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)
- 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)
Also on the rendered model, you see your results in a clear color display. Thus, you can exactly recognize the rotation of a member or the stress distribution in a surface, for example. If you want to set the colors and value ranges, you can easily do so in the control panel.
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.
In SHAPE-THIN 8, the effective cross-section of stiffened buckling panels can be calculated according to EN 1993-1-5, Cl. 4.5.
The critical buckling stress is calculated according to EN 1993-1-5, Annex A.1 for buckling panels with at least 3 longitudinal stiffeners, or according to EN 1993-1-5, Annex A.2 for buckling panels with one or two stiffeners in the compression zone. The design for torsional buckling safety is also performed.
- Import of materials, cross-sections, and internal forces from RFEM/RSTAB
- Steel design of thin‑walled cross‑sections according to EN 1993‑1‑1:2005 and EN 1993‑1‑5:2006
- Automatic classification of cross-sections according to EN 1993-1-1:2005 + AC:2009, Cl. 5.5.2, and EN 1993-1-5:2006, Cl. 4.4 (cross-section class 4), with optional determination of effective widths according to Annex E for stresses under fy
- Integration of parameters for the following National Annexes:
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DIN EN 1993-1-1/NA:2015-08 (Germany)
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ÖNORM B 1993-1-1:2007-02 (Austria)
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NBN EN 1993-1-1/ANB:2010-12 (Belgium)
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BDS EN 1993-1-1/NA:2008 (Bulgaria)
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DS/EN 1993-1-1 DK NA:2015 (Denmark)
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SFS EN 1993-1-1/NA:2005 (Finland)
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NF EN 1993-1-1/NA:2007-05 (France)
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ELOT EN 1993-1-1 (Greece)
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UNI EN 1993-1-1/NA:2008 (Italy)
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LST EN 1993-1-1/NA:2009-04 (Lithuania)
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UNI EN 1993-1-1/NA:2011-02 (Italy)
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MS EN 1993-1-1/NA:2010 (Malaysia)
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NEN EN 1993-1-1/NA:2011-12 (Netherlands)
- NS EN 1993-1-1/NA:2008-02 (Norway)
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PN EN 1993-1-1/NA:2006-06 (Poland)
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NP EN 1993-1-1/NA:2010-03 (Portugal)
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SR EN 1993-1-1/NB:2008-04 (Romania)
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SS EN 1993-1-1/NA:2011-04 (Sweden)
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SS EN 1993-1-1/NA:2010 (Singapore)
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STN EN 1993-1-1/NA:2007-12 (Slovakia)
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SIST EN 1993-1-1/A101:2006-03 (Slovenia)
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UNE EN 1993-1-1/NA:2013-02 (Spain)
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CSN EN 1993-1-1/NA:2007-05 (Czech Republic)
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BS EN 1993-1-1/NA:2008-12 (the United Kingdom)
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CYS EN 1993-1-1/NA:2009-03 (Cyprus)
- In addition to the National Annexes (NA) listed above, you can also define a specific NA, applying user‑defined limit values and parameters.
- Automatic calculation of all required factors for the design value of flexural buckling resistance Nb,Rd
- Automatic determination of the ideal elastic critical moment Mcr for each member or set of members on every x-location according to the Eigenvalue Method or by comparing moment diagrams. You only have to define the lateral intermediate supports.
- Design of tapered members, unsymmetric sections or sets of members according to the General Method as described in EN 1993-1-1, Cl. 6.3.4
- In the case of the General Method according to Cl. 6.3.4, optional application of "European lateral-torsional buckling curve" according to Naumes, Strohmann, Ungermann, Sedlacek (Stahlbau 77 [2008], pp. 748‑761)
- Rotational restraints can be taken into account (trapezoidal sheeting and purlins)
- Optional consideration of shear panels (for example, trapezoidal sheeting and bracing)
- RF-/STEEL Warping Torsion module extension (license required) for stability analysis according to the second-order analysis as stress analysis including consideration of the 7th degree of freedom (warping)
- Module extension RF-/STEEL Plasticity (license required) for plastic analysis of cross‑sections according to Partial Internal Forces Method (PIFM) and Simplex Method for general cross‑sections (in connection with the RF‑/STEEL Warping Torsion module extension, it is possible to perform the plastic design according to the second‑order analysis)
- Module extension RF-/STEEL Cold-Formed Sections (license required) for ultimate and serviceability limit state designs for cold-formed steel members according to the EN 1993-1-3 and EN 1993-1-5 standards
- ULS design: Selection of fundamental or accidental design situations for each load case, load combination, or result combination
- SLS design: Selection of characteristic, frequent, or quasi-permanent design situations for each load case, load combination, or result combination
- Tension analysis with definable net cross-section areas for member start and end
- Weld designs of welded cross-sections
- Optional calculation of warp spring for nodal support on sets of members
- Graphic of design ratios on cross-section and in RFEM/RSTAB model
- Determination of governing internal forces
- Filter options for graphical results in RFEM/RSTAB
- Representation of design ratios and cross‑section classes in the rendered view
- Color scales in result windows
- Automatic cross-section optimization
- Transfer of optimized cross-sections to RFEM/RSTAB
- Parts lists and quantity surveying
- Direct data export to MS Excel
- Verifiable printout report
- Possibility to include the temperature curve in the report
- Modeling of the cross-section via elements, sections, arcs, and point elements
- Expansible library of material properties, yield strengths, and limit stresses
- Section properties of open, closed, or non-connected cross-sections
- Ideal section properties of cross-sections consisting of different materials
- Determination of weld stresses in fillet welds
- Stress analysis including design of primary and secondary torsion
- Check of c/t-ratios
- Effective cross-sections according to
- EN 1993-1-5 (including stiffened buckling panels according to Section 4.5)
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EN 1993-1-3
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EN 1999-1-1
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to DIN 18800-2
- Classification according to
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EN 1993-1-1
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EN 1999-1-1
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- Interface with MS Excel to import and export tables
- Printout report
SHAPE-THIN calculates all relevant cross‑section properties, including plastic limit internal forces. Overlapping areas are set close to reality. If cross-sections consist of different materials, SHAPE‑THIN determines the effective cross‑section properties with respect to the reference material.
In addition to the elastic stress analysis, you can perform the plastic design including interaction of internal forces for any cross‑section shape. The plastic interaction design is carried out according to the Simplex Method. You can select the yield hypothesis according to Tresca or von Mises.
SHAPE-THIN performs a cross-section classification according to EN 1993-1-1 and EN 1999-1-1. For steel cross-sections of cross-section class 4, the program determines effective widths for unstiffened or stiffened buckling panels according to EN 1993-1-1 and EN 1993-1-5. For aluminum cross-sections of cross-section class 4, the program calculates effective thicknesses according to EN 1999-1-1.
Optionally, SHAPE‑THIN checks the limit c/t-values in compliance with the design methods el‑el, el‑pl, or pl‑pl according to DIN 18800. The c/t-zones of elements connected in the same direction are recognized automatically.
RF-/STEEL EC3 automatically imports the cross-sections defined in RFEM/RSTAB. It is possible to design all thin-walled cross-sections. The program automatically selects the most efficient method according to standards.
The ultimate limit state design takes into account several loads and you can select the interaction designs available in the standard.
The classification of designed cross-sections into Classes 1 to 4 is an essential part of the analysis according to Eurocode 3. This way, you can check the limitation of the design and rotational capacity by means of the local buckling of cross-section parts. RF-/STEEL EC3 determines the c/t-ratios of the cross-section parts subjected to compression stress and performs the classification automatically.
For the stability analysis, you can specify for each member or set of members whether flexural buckling occurs in the y- and/or the z-direction. You can also define additional lateral restraints in order to represent the model close to reality. The slenderness ratio and elastic critical load are determined automatically on the basis of the boundary conditions of RF-/STEEL EC3. The elastic critical moment for lateral-torsional buckling required for the lateral-torsional buckling analysis can be determined automatically or specified manually. The load application point of transverse loads, which has an influence on the torsional resistance, can also be taken into account via the setting in the details. In addition, you can take into account rotational restraints (for example trapezoidal sheeting and purlins) and shear panels (for example trapeziodal sheeting and bracing).
In modern construction, where cross-sections are increasingly slender, the serviceability limit state is an important factor in structural analysis. RF-/STEEL EC3 assigns load cases, load combinations, and result combinations to different design situations. The respective limit deformations are preset in the National Annex and can be adjusted, if necessary. In addition, it is possible to define reference lengths and precambers for the design.
The results on a rendered model are represented by a number of colors in order to easily detect deformations such as member rotation. You can freely define the colors and the range of values in the control panel. Deformations, surface stresses, and internal forces can be animated and saved as a video file.
The results on a rendered model are represented by a number of colors in order to easily detect deformations such as member rotation. You can freely define the colors and the range of values in the control panel. Deformation diagrams can be animated and saved as a video file.
- For the design according to Eurocode 3, the following National Annexes are available:
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DIN EN 1993-1-5/NA:2010-12 (Germany)
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SFS EN 1993-1-5/NA:2006 (Finland)
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NBN EN 1993-1-5/NA:2011-03 (Belgium)
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UNI EN 1993-1-5/NA:2011-02 (Italy)
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NEN EN 1993-1-5/NA:2011-04 (Netherlands)
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NS EN 1993-1-5/NA:2009-06 (Norway)
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CSN EN 1993-1-5/NA:2008-07 (Czech Republic)
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CYS EN 1993-1-5/NA:2009-03 (Cyprus)
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- In addition to the National Annexes listed above, you can also define a specific NA, applying user-defined limit values and parameters.
- Import of all relevant internal forces from RFEM/RSTAB by selecting numbers of members and buckling panels with determination of governing boundary stresses
- Summary of stresses in load cases with determination of governing load
- Different materials for stiffener and plate possible
- Import of stiffeners from an extensive library (flat plate and bulb flat steel, angle, T-section, channel, and trapezoidal sheeting)
- Determination of effective widths according to EN 1993-1-5 (Table 4.1 or 4.2) or DIN 18800, Part 3, Eq. (4)
- Optional calculation of critical buckling stresses according to analytical formulas of annexes A.1, A.2, and A.3 of EC 3, or by means of FEA calculation
- Designs (stress, deformation, torsional buckling) of longitudinal and transverse stiffeners
- Optional consideration of buckling effects according to DIN 18800, Part 3, Eq. (13)
- Photo-realistic representation (3D rendering) of buckling panel, including stiffeners, stress conditions, and buckling modes with animation
- Documentation of all input data and results in a verifiable printout report
Comprehensive and easy options in the individual input windows facilitate the representation of the structural system:
Nodal Supports
- The support type of each node is editable.
- It is possible to define a warp stiffening on each node. The resulting warp spring is determined automatically using the input parameters.
Elastic member foundation
- In the case of elastic member foundations, you can manually enter spring constants.
- Alternatively, you can use the various options to define the rotational and translational springs from a shear panel.
Member End Springs
- RF-/FE-LTB calculates the individual spring constants automatically. You can use the dialog boxes and detailed pictures to represent a translational spring by connecting component, a rotational spring by a connecting column, or a warping stiffener (available types: end plate, channel section, angle, connecting column, cantilevered portion).
Member Hinges
- If there are no member hinges defined in RFEM/RSTAB for the set of members, you can define them directly in the RF-/FE-LTB add-on module.
Load Data
- The nodal and member loads of the selected load cases and combinations are displayed in separate windows. There you can edit, delete, or add them individually.
Imperfections
- RF-/FE-LTB automatically applies the imperfections by scaling the lowest eigenvector.
The details for the lateral-torsional buckling analysis are defined separately for members and sets of members. The following parameters can be set:
Support Type/Lateral-Torsional Buckling Load
- Available options are Lateral and torsional restraint, Lateral and torsional restraint or Cantilever
- Special supports are possible by specifying the degree of restraint βz and the degree of warping restraint β0. In this section as well, you can consider the elastic warping restraint of an end plate, a channel section, an angle, a column connection, and a beam cantilever by specifying the geometry dimensions.
- As an alternative, it is also possible to enter the lateral-torsional buckling load NKi or the effective length sKi directly
Shear panel
- A shear panel can be defined from a trapezoidal sheeting, bracing, or a combination of these
- Alternatively, you can enter the shear panel stiffness Sprov directly
Rotational restraint
- Choose between continuous and discontinuous rotational restraint
Position of Positive Transverse Load Application
- The z-coordinate of the load application point can be freely selected in a detailed cross-section graphic. (upper chord, lower chord, centroid)
- Alternatively, you can specify the data by selecting them or entering the data manually.
Beam Type
- For standard sections, the rolled beam, welded beam, castellated beam, notched beam, or tapered beam (web or flange welded) options are available
- For special cross-sections, it is possible to directly enter the beam factor n, the reduced beam factor n, or the reduction factor κM
- Full integration in RFEM/RSTAB, including import of all relevant loads
- General stress analysis with warping torsion according to elastic-elastic method
- Stability analysis of planar continuous members for buckling and lateral-torsional buckling
- Determination of critical load factor and thus of Mcr or Ncr (the factor can be used in RF-/LTB for the el/pl design)
- Lateral-torsional buckling analysis of any cross-section (also the SHAPE-THIN cross-sections)
- Design of members and sets of members with applied torsion (for example, crane girder)
- Optional determination of the limit load factor (critical load factor)
- Display of eigenmodes and torsional modes on the rendered cross-section
- Wide range of tools for determining shear panels and rotational restraints (such as corrugated sheets, purlins, bracings)
- Easy determination of discrete springs such as warp springs from end plates or rotational springs from columns
- Graphical selection of load application points on a cross-section (upper chord, centroid, lower chord, or any other point)
- Free arrangement of eccentric nodal and line supports on a cross-section
- Determination of value for inclination or precamber by means of eigenvalue analysis
- Special warping releases applicable for definition of warping conditions on transitions
The designs are carried out step-by-step by the eigenvalue calculation of the ideal buckling values for the individual stress states, as well as the buckling value for the simultaneous effect of all stress components.
The buckling analysis is based on the method of reduced stresses, comparing the acting stresses to a limit stress condition reduced from the yield condition of von Mises for each buckling panel. The design is based on a single global slenderness ratio determined by the entire stress field. Therefore, the design of single loading and subsequent merging using interaction criterion is omitted.
In order to determine the plate buckling behavior, which is similar to the behavior of a buckling member, the module calculates the eigenvalues of the ideal panel buckling values using freely assumed longitudinal edges. Then, slenderness ratios and reduction factors according to EN 1993-1-5, Ch. 4 or Annex B or DIN 18800, Part 3, Table 1. The design is then performed according to EN 1993-1-5, Chapter. 10 or DIN 18800, Part 3, Eq. (9), (10) or (14).
The buckling panel is discretized in finite quadrilateral or, if necessary, triangular elements. Each element node has six degrees of freedom.
The bending component of a triangular element is based on the LYNN-DHILLON element (2nd Conf. Matrix Meth. JAPAN – USA, Tokyo) according to the bending theory of Mindlin. However, the membrane component is based on the BERGAN-FELIPPA element. The quadrilateral elements consist of four triangular elements, while the inner node is eliminated.
Initially, it is necessary to define material data, panel dimensions, and boundary conditions (hinged, built-in, unsupported, hinged-elastic). It is possible to transfer the data from RFEM/RSTAB. Then, boundary stresses can be either defined for each load case manually or imported from RFEM/RSTAB.
Stiffeners are modeled as spatially effective surface elements that are eccentrically connected to the plate. Therefore, it is not necessary to consider the stiffener eccentricities by effective widths. The bending, shear, strain, and St. Venant stiffness of stiffeners as well as the Bredt stiffness of closed stiffeners is determined automatically in a 3D model.
The results are displayed with references to EN 1993-1-5 or DIN 18800. In addition, RF-/PLATE-BUCKLING shows calculation results separately for the action of only one edge load as well as for the simultaneous effect of all edge loads.
In the case of several load cases, the governing load case is displayed separately. Thus, time-consuming comparison of calculation data is not necessary.
Window 2.5 lists the critical buckling load factors of all load cases and the respective buckling modes.
You can visualize the buckling modes and loads of the buckling panel in the graphic window. This facilitates a quick overview of the buckling modes and loads. Using the animation option, you can clearly represent the buckling behavior of stiffened plates.
Finally, it is possible to export all tables to MS Excel or in a CSV file.
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.