Using the "Damper" member type, you can define a damping coefficient, a spring constant, and a mass. This member type extends the possibilities within the Time History Analysis.
With regard to viscoelasticity, the "Damper" member type is similar to the Kelvin-Voigt model, which consists of the damping element and an elastic spring (both connected in parallel).
The Steel Joints add-on provides you with the option to connect circular hollow sections using welds.
It is possible to connect the circular sections to each other or to planar structural components. The fillets of standard and thin-walled sections can also be connected with a weld.
In the "Steel Joints" add-on, you can consider preloaded bolts in all components during the calculation. You can easily activate the preloading using the check box in the bolt parameters, and it has an impact on the stress-strain analysis as well as the stiffness analysis.
Preloaded bolts are special bolts used in steel structures to generate a high clamping force between the connected structural components. This clamping force causes friction between the structural components, which allows for the transfer of forces.
Functionality Preloaded bolts are tightened with a certain torque, causing them to stretch and generate a tensile force. This tensile force is transferred to the connected components and leads to a high clamping force. The clamping force prevents the connection from loosening and ensures safe force transmission.
Advantages
High load-bearing capacity: Preloaded bolts can transfer large forces.
Low deformation: They minimize the deformation of the connection.
Fatigue strength: They are resistant to fatigue.
Easy assembly: They are relatively easy to assemble and disassemble.
Analysis and Design The calculation of preloaded bolts is performed in RFEM using the FE analysis model generated by the "Steel Joints" add-on. It takes into account the clamping force, friction between structural components, shear strength of bolts, and load-bearing capacity of the structural components. The design is carried out according to DIN EN 1993‑1‑8 (Eurocode 3) or the US standard ANSI/AISC 360‑16. You can save the created analysis model, including the results, and use it as an independent RFEM model.
No manual editing of the FE model required by the user, the essential calculation settings can be changed via the configuration settings
Automatic adaptation of the connection geometry, even if the members are subsequently edited, due to the relative relation of the components to each other
Parallel to the input, a plausibility check is carried out by the program to quickly detect missing input or collisions, for example
Graphical display of the connection geometry that is updated in parallel with the input
You can perform the calculation of the warping torsion on the entire system. Thus, you consider the additional 7th degree of freedom in the member calculation. The stiffnesses of the connected structural elements are automatically taken into account. It means, you don't need to define equivalent spring stiffnesses or support conditions for a detached system.
You can then use the internal forces from the calculation with warping torsion in the add-ons for the design. Consider the warping bimoment and the secondary torsional moment, depending on the material and the selected standard. A typical application is the stability analysis according to the second-order theory with imperfections in steel structures.
Did you know that The application is not limited to thin-walled steel cross-sections. Thus, it is possible for you, for example, to perform the calculation of the ideal overturning moment of beams with solid timber cross-sections.
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)
The member type 'Dashpot' can be used for time history analyzes in RFEM/RSTAB with the add-on modules RF-/DYNAM Pro - Forced Vibrations and RF-/DYNAM Pro - Nonlinear Time History. This linear viscous damping element considers forces dependent on velocity.
With regard to viscoelasticity, the member type 'Dashpot' is similar to the Kelvin-Voigt model, which consists of the damping element and an elastic spring (both connected in parallel).
First, select the joint type and the design standard.
The connected members are imported from the RFEM/RSTAB model. The add-on module automatically checks if all geometry conditions are fulfilled.
In addition, the loads are imported automatically from RFEM/RSTAB. In the Geometry window, you can specify the screw parameters (diameter, length, angle, and so on).
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.
After opening the add-on module, it is necessary to select the joint type (end plate or bracket). You can select the individual nodes graphically in the RFEM/RSTAB model.
The RF-/JOINTS Steel - SIKLA add‑on module checks the cross‑section and materials of the connected members. It is possible to model and design structurally similar connections on several locations in the structure.
The RF-/FRAME-JOINT Pro add-on module designs connections of structures calculated in RFEM/RSTAB. If there is no RFEM/RSTAB structure available, you can define the geometry and loading manually; for example, when checking external calculations, for example.
Designed nodes are usually imported from RFEM/RSTAB. The module recognizes all connected members automatically and assigns a connection type to them. Depending on the connection type, you can define further details of ribs, backing plates, web plates, bolts, welds, and hole spacing. As loads, you can select any load case, load combination or result combination in RFEM/RSTAB.
In the case of the "preliminary design" calculation mode, RF-/FRAME-JOINT Pro performs the first calculation step to suggest applicable layouts. After you select the relevant layout, the module displays all designs in detailed result tables and various graphics.
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.
You can define built-up timber cross-sections, for example, channel, T, I, and box girders. Single elements are connected by rigid or semi‑rigid connections. Furthermore, hybrid cross-sections are available. In this case, a submenu provides an option to assign different materials to the individual cross‑section parts.
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.