In the Steel Design add-on, you can apply a value for cold-formed sections according to EN 1993‑1‑3, which performs the stability analysis and cross-section design according to Sections 6.1.2 - 6.1.5 and 6.1.8 - 6.1.10.
Would you like to perform cross-section design checks for cold-formed steel members according to EN 1993‑1‑3? No matter if you design the cold-formed sections from the cross-section library or the general cold-formed (non-perforated) sections from RSECTION – your structural analysis program helps you to determine the effective cross-section, taking into account the local buckling and instability. You can also perform a cross-section check according to EN 1993‑1‑3, 6.1.6. In this case, the internal forces from the calculation using Torsional Warping (7 DOF) are taken into account by means of the equivalent stress check
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.
When performing a design according to EN 1993‑1‑3, it is possible to graphically display a mode shape for the distortional buckling of a cross-section, and for the RSECTION cross-sections.
The mode shape can also be output in RSECTION 1 for library cross-sections.
The design checks for the members you have selected are carried out taking into account the governing component temperature. You can perform the cross-section design checks and stability analyses according to EN 1993‑1‑2, Section 4.2.3, in the Steel Design add-on. All reduction factors and coefficients that are necessary are stored accordingly and are taken into account when determining the load-bearing capacity.
The effective lengths for the equivalent member design are taken directly from the strength entries. You don't need to enter them again.
In each design, perform the cross-section classification first. For the cross-sections of Class 4, the design is performed automatically according to EN 1993‑1‑2, Annex E.
The Steel Design add-on helps you, among other things, to design general cross-sections that are not predefined in the cross-section library. To do this, create a cross-section in the RSECTION program and then import it into RFEM/RSTAB. Depending on the design standard that you have used, you can select from various design formats. One of them is, for example, the equivalent stress analysis. Do you have a license for RSECTION and Effective Cross-Sections? Then you can also perform the design checks that take into account the effective cross-section properties according to EN 1993‑1‑5.
Did you use the eigenvalue solver of the add-on to determine the critical load factor for the stability analysis? Verz well, you can then display the governing mode shape of the object to be designed as a result. The eigenvalue solver is available for the lateral-torsional buckling analysis, depending on the design standard used. You can also use the internal eigenvalue solver for the general method according to EN 1993‑1‑1, 6.3.4.
In this case, you calculate the critical load factor for all analyzed load combinations and the selected number of mode shapes for the connection model. Compare the smallest critical load factor with the limit value 15 from the standard EN 1993‑1‑1, Clause 5. Furthermore, you can make user-defined adjustment of the limit value. As a result of the stability analysis, the program displays the corresponding mode shapes graphically.
For the stability analysis, RFEM uses the adapted surface model to specifically recognize the local buckling shapes. You can also save and use the model of the stability analysis, including the results, as a separate model file.
Do you work with steel connections? The Steel Joints add-on for RFEM supports you when analyzing steel connections by using an FE model. In this case, the modeling runs fully automatically in the background. Nevertheless, you can control this process via the simple and familiar input of components. You can then use the loads determined on the FE model for your design of the components according to EN 1993‑1‑8 (including National Annexes).
Compared to the RF‑/STEEL EC3 add-on module (RFEM 5 / RSTAB 8), the following new features have been added to the Steel Design add-on for RFEM 6 / RSTAB 9:
In addition to Eurocode 3, other international standards are integrated (such as AISC 360, CSA S16, GB 50017, SP 16.13330)
Consideration of hot-dip galvanizing (DASt guideline 027) in the fire protection design according to EN 1993‑1‑2
Input option for transverse stiffeners that can be taken into account in the shear buckling analysis
Lateral-torsional buckling can also be checked for hollow sections (for example, relevant for slender, high rectangular hollow sections)
Automatic detection of members or member sets valid for the design (for example, automatic deactivation of members with invalid material or members already contained in a member set)
Design settings can be adjusted individually for each member
Graphical display of the results in the gross section or the effective section
Output of the used design check formulas (including a reference to the used equation from the standard)
Available for general thin-walled RSECTION cross-sections
Classification according to
EN 1993-1-1
EN 1993-1-4
EN 1999-1-1
Determination of the effective section according to
EN 1993-1-5
EN 1993-1-3
EN 1999-1-1
Consideration of the effects of distortional buckling of cold-formed sections via eigenvalue method
Determination of the stresses on the effective section and gross section
Cross-section, stability, and serviceability limit state design checks of RSECTION cross-sections of Class 4 according to EN 1993‑1‑1 or EN 1999‑1‑1 in the Steel Design or Aluminum Design add-ons
Cross-section checks for cold-formed RSECTION cross-sections according to EN 1993‑1‑3 in the Steel Design add-on
Available for all National Annexes integrated in the Steel Design add-on
The program can also help you here. It determines the bolt forces on the basis of the calculation on the FE model and evaluates them automatically. You can perform the design checks of the bolt resistance for the failure cases tension, shear, hole bearing, and punching shear according to the standard. The program takes care of everything else in this step. It determines all the necessary coefficients and displays them clearly.
Do you want to perform weld design? The required stresses are also determined on the FE model in that case. Then, the Weld element is modeled as elastic-plastic shell element, where every FE element is checked for its internal forces. (Plasticity criteria is set to reflect failure acc. to AISC J2-4 and J2-5 (weld resistance check) and also J2-2 (base metal capacity check). The design can also be carried out with the partial safety factors according to the selected National Annex.
You can perform the plate design plasticall by comparing the existing plastic strain to the allowable plastic strain. By default this is set to 5% for the AISC 360 but can be specified through user-definition 5% according to EN 1993-1-5, Annex C, or again, user-defined specification.
Design of tension, compression, bending, shear, torsion, and combined internal forces
Tension design with consideration of a reduced section area (for example, hole weakening)
Automatic classification of cross-sections to check local buckling
Internal forces from the calculation with Torsional Warping (7 DOF) are taken into account by means of the equivalent stress check (currently not for the design standards AISC 360‑16 and GB 50017).
Design of cross-sections of Class 4 with effective cross-section properties according to EN 1993‑1‑3 (licenses for RSECTION and Effective Sections are required for the RSECTION cross-sections)
Shear buckling check according to EN 1993‑1‑5 with consideration of transverse stiffeners
Design of stainless steel components according to EN 1993‑1‑4
Design of tension, compression, bending, shear, torsion, and combined internal forces
Tension design with consideration of a reduced section area (for example, hole weakening)
Automatic classification of cross-sections to check local buckling
Internal forces from the calculation with Torsional Warping (7 DOF) are taken into account by means of the equivalent stress check (currently not yet for the design standard ADM 2020).
Design of cross-sections of Class 4 with effective cross-section properties according to EN 1993‑1‑5 (licenses for RSECTION and Effective Sections are required for the RSECTION cross-sections)
Shear buckling check with consideration of transverse stiffeners
You can keep track of things with just a few clicks. A global dialog box manages the units for input data, loads, and results in RFEM or RSTAB, as well as in all add-ons.
You can save the settings and import them again later. In this way, it is possible for you to use different sections in steel and reinforced concrete structures, for example.
SHAPE‑THIN determines the effective cross-sections according to EN 1993‑1‑3 and EN 1993‑1‑5 for cold-formed sections. You can optionally check the geometric conditions for the applicability of the standard specified in EN 1993‑1‑3, Section 5.2.
The effects of local plate buckling are considered according to the method of reduced widths, and the possible buckling of stiffeners (instability) is considered for stiffened sections according to EN 1993‑1‑3, Section 5.5.
As an option, you can perform an iterative calculation to optimize the effective cross-section.
You can display the effective cross-sections graphically.
Read more about designing cold-formed sections with SHAPE-THIN and RF-/STEEL Cold-Formed Sections in the technical article "Design of Thin-Walled, Cold-Formed C-Section According to EN 1993‑1‑3".
Available for cold-formed L, Z, C, channel, top-hat, and CL sections from the cross-section database, as well as for general cold-formed (non-perforated) SHAPE-THIN-9 sections
Determination of the effective cross-section considering the local buckling and the distortional buckling
Cross-section ultimate limit state, stability, and serviceability limit state designs according to EN 1993‑1‑3
Design of local transverse forces for webs without stiffening
Available for all National Annexes included in RF-/STEEL EC3
Module extension RF-/STEEL Warping Torsion (license required) for stability analysis according to second-order analysis as stress analysis including consideration of the 7th degree of freedom (warping)
Beam to Column joint category: connection possible as joint of the beam to the column flange as well as joint of the column to the girder flange
Beam to Beam joint category: design of beam joints as both moment-resisting end plate connections and rigid splice connections possible
Automatic export of model and load data possible from RFEM or RSTAB
Bolt sizes from M12 to M36 with strength grades 4.6, 4.8, 5.6, 5.8, 6.8, 8.8, and 10.9 as long as the strength grades are available in the selected National Annex
Almost any bolt spacing and edge distances (a check of the allowable distances is performed)
Beam strengthening with tapers or stiffeners on the top and bottom surfaces
End plate connection with and without overlap
Connection with pure bending stress, pure normal force load (tension joint), or combination of normal force and bending possible
Calculation of connection stiffnesses and check if a hinged, semi-rigid, or rigid connection exists
End plate connection in a beam-column setup
Joint beams or columns can be stiffened with tapers on one side or with stiffeners to one or both sides
Wide range of possible stiffeners of the connection (for example, complete or incomplete web stiffeners)
Up to ten horizontal and four vertical bolts possible
Connected object possible as constant or tapered I-section
Designs:
Ultimate limit state of the connected beam (such as shear or tension resistance of the web plate)
Ultimate limit state of the end plate at the beam (for example, T-stub under tensile stress)
Ultimate limit state of the welds at the end plate
Ultimate limit state of the column in the area of the connection (for example, column flange under bending – T-stub)
All designs are performed according to EN 1993-1-8 and EN 1993-1-1
Moment-resisting end plate joint
Two or four vertical and up to 10 horizontal bolt rows
Joint beams can be stiffened with tapers on one side or with stiffeners to one or both sides
Connected objects are possible as constant or tapered I-sections
Designs:
Ultimate limit state of the connected beams (such as shear or tension resistance of the web plates)
Ultimate limit state of the end plates at the beam (for example, T-stub under tensile stress)
Ultimate limit state of the welds at the end plates
Ultimate limit state of the bolts in the end plate (combination of tension and shear)
Rigid splice plate connection
For the flange plate connection, up to ten bolt rows one behind the other possible
For the web plate connection, up to ten bolt rows possible each in vertical and horizontal directions
Material of the cleat can be different from the one of the beams
Designs:
Ultimate limit state of the joint beams (for example, net cross-section in the tension area)
Ultimate limit state of the cleat plates (for example, net cross-section under tensile stress)
Ultimate limit state of the single bolts and the bolt groups (for example, shear resistance design of the single bolt)
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:
DIN EN 1993-1-1/NA:2015-08 (Germany)
ÖNORM B 1993-1-1:2007-02 (Austria)
NBN EN 1993-1-1/ANB:2010-12 (Belgium)
BDS EN 1993-1-1/NA:2008 (Bulgaria)
DS/EN 1993-1-1 DK NA:2015 (Denmark)
SFS EN 1993-1-1/NA:2005 (Finland)
NF EN 1993-1-1/NA:2007-05 (France)
ELOT EN 1993-1-1 (Greece)
UNI EN 1993-1-1/NA:2008 (Italy)
LST EN 1993-1-1/NA:2009-04 (Lithuania)
UNI EN 1993-1-1/NA:2011-02 (Italy)
MS EN 1993-1-1/NA:2010 (Malaysia)
NEN EN 1993-1-1/NA:2011-12 (Netherlands)
NS EN 1993-1-1/NA:2008-02 (Norway)
PN EN 1993-1-1/NA:2006-06 (Poland)
NP EN 1993-1-1/NA:2010-03 (Portugal)
SR EN 1993-1-1/NB:2008-04 (Romania)
SS EN 1993-1-1/NA:2011-04 (Sweden)
SS EN 1993-1-1/NA:2010 (Singapore)
STN EN 1993-1-1/NA:2007-12 (Slovakia)
SIST EN 1993-1-1/A101:2006-03 (Slovenia)
UNE EN 1993-1-1/NA:2013-02 (Spain)
CSN EN 1993-1-1/NA:2007-05 (Czech Republic)
BS EN 1993-1-1/NA:2008-12 (the United Kingdom)
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
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.