- The proposed connection can be applied to all selected nodes in the structure
- The location of the connection can be defined using the 'Main' tab of the Add-on dialog box
- The design is performed for all connections in the structure and after the calculation, the results on all connections can be displayed
- The table shows the results for the individual connections, each connection is designed and can be saved separately
Complex Connection of Horizontal Beams to Column and Connection of Reinforcing Diagonals
The connection model was modeled using about 50 components. The model was created according to the real example of use in structure.
To determine the shear resistance of bolts, you can use the Steel Joints add-on to specify whether there is a shaft or a thread in the shear plane.
Go to Explanatory VideoIn the case of rectangular cross-sections, you can usually achieve a direct connection by using welds. However, you can also connect them to other cross-sections in the same way. Furthermore, other components such as end plates help you to connect the rectangular cross-sections to other structural components.
Steel bolted connections with gusset plates on the canopy structure.
Download the structural analysis model and open it with the finite element program RFEM 6 using Steel Joints Add-on.
In the Steel Joint add-on, you can design the connections of members with composite cross-sections. Furthermore, you can perform joint design checks for almost all thin-walled cross-sections in the RFEM library.
Go to Explanatory VideoDesign of a frame connection with taper and stiffened members. A stress analysis and a buckling stability analysis were carried out for the connection. To display the buckling results, the connection was converted into a separate model.
Here, the weld design becomes child's play. Using the specially developed material model "Orthotropic | Plastic | Weld (Surfaces)", you can calculate all stress components plastically. The stress τperpendicular is also considered plastically.
Using this material model you can design welds closer to reality and more efficiently.
Explanatory VideoThe program supports you: It determines the bolt forces on the basis of the FE analysis model and evaluates them automatically. The add-on performs the standard-compliant design of bolt resistance for failure cases, such as tension, shear, hole bearing, and punching, and clearly displays all required coefficients.
Do you want to perform weld design? The welds are modeled as elastic-plastic surface elements, and their stresses are read out from the FE analysis model. The plasticity criteria is set in the way that they represent failure according to AISC J2-4, J2-5 (strength of welds), and J2-2 (strength of base metal). The design can be performed with the partial safety factors of the selected National Annex of EN 1993‑1‑8.
The plates in the connection are designed plastically by comparing the existing plastic strain to the allowable plastic strain. The default setting is 5% according to EN 1993‑1‑5, Annex C, but can be adjusted by user-defined specifications, as well as 5% for AISC 360.
Using the "Connecting Plate" component, you can additionally and automatically create a new gusset plate in the Steel Joints add-on. This saves you separate components, and the other elements, such as a cap plate and a slide plate, are thus automatically taken into account with their dimensions.
Go to Explanatory Video- Many predefined components: Allow easy input of typical connection situations, such as end plates, angles, multi-wall sheets, cleats, fin plates
- Universally applicable basic components (plates, welds, bolts, auxiliary planes) for entering complex connection situations
- Graphical display of the connection geometry that is updated in parallel with the input
- The Steel Joints Template included in the add-on allows you to select from several connection types and, and once selected, it will be applied to your model.
- Wide range of cross-section shapes: Includes I-sections, channel sections, angles, T-sections, built-up cross-sections, RHS (rectangular hollow sections), and thin-walled sections
- The Template covers connections from three general categories: Rigid, Pinned, Truss
- Automatic adaptation of the connection geometry, even if the structural components are subsequently edited, based on the relative relation of the components
RFEM allows you to use a special line hinge to model the special properties of the connection between the reinforced concrete slab and masonry wall. This limits the transferable forces of the connection depending on the specified geometry. You guess right: This means that the material cannot be overloaded.
The program develops interaction diagrams that are applied automatically. They represent the various geometric situations and you can use them to determine the correct stiffness.
If a weld seam connects two plates with different materials, it is possible to select from a combo box in the Steel Joints add-on which one of both materials should be used for the weld seam.
Go to Explanatory VideoThe "Member Editor" component allows you to modify the individual or several member plates in the Steel Joints add-on.
You can use the chamfer, notch, rounding, and hole operations with multiple shapes. It is possible to apply both operations, "Notch" and "Chamfer", for several member plates.
In this way, you can notch flanges from I-sections, for example (see the image).
Go to Explanatory VideoThe initial stiffness Sj,ini is a crucial parameter for evaluating whether a connection can be characterized as rigid, semi-rigid, or pinned.
In the "Steel Joints" add-on, you can calculate the initial stiffness Sj,ini according to Eurocode (EN 1993‑1‑8, Section 5.2.2) and AISC (AISC 360-16, Cl. E3.4) with regard to the internal forces N, My, and/or Mz.
The optional automatic transfer of initial stiffnesses allows for a directly transfer as member hinge stiffnesses in RFEM. The entire structure is then recalculated and the resulting internal forces are automatically adopted as loads in the analysis and design of the connection models.
This automated iteration process eliminates the need for manual export and import of data, reducing the amount of work and minimizing potential sources of error.
Explanatory Video: Calculation of Initial Stiffness Sj,ini- 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
In the Steel Joints add-on, you can design connections according to the American standard ANSI/AISC 360‑16. The following design procedures are integrated:
- Load and Resistance Factor Design (LRFD)
- Allowable Stress Design (ASD)
Are you ready for the evaluation? Use the calculation diagrams, which show the distribution of a specific result during the calculation.
You can freely define the layout of the vertical and horizontal axes of the calculation diagram. This allows you, for example, to consider the settlement distribution of a certain node, depending on the load.
In addition to other predefined components in the design add-on for steel connections, the universal base component "General Weld" can be used to enter complex connection situations.
Do you want to model and analyze the behavior of a soil solid? To ensure this, special suitable material models have been implemented in RFEM.
You can use the modified Mohr-Coulomb model with a linear-elastic ideal-plastic model or a nonlinear elastic model with an oedometric stress-strain relation. The limit criterion, which describes the transition from the elastic area to that of the plastic flow, is defined according to Mohr-Coulomb.
To design a Steel connection, you must have the Steel Joints Add-on enabled. The Add-ons in RFEM 6 are activated in the Add-ons tab of the Edit Model - Base Data window. If the Add-on is active, it is displayed in the navigator.
Did you know that To calculate masonry structures, a nonlinear material model has been implemented in RFEM. It is based on the approach of Lourenco, a composite yield surface according to Rankine and Hill. This model allows you to describe and model the structural behavior of masonry and the different failure mechanisms.
The limit parameters were selected in such a way that the design curves used correspond to a normative design curve.
In the Steel Joints add-on, you can classify the joint stiffness.
In addition to the initial stiffness, the table also shows the limit values for hinged and rigid connections for the selected internal forces N, My, and/or Mz. The resulting classification is then displayed in tables as "hinged", "semi-rigid", or "rigid".
Go to Explanatory VideoAmong others, the following cross-laminated timber manufacturers are available in the layer structure library:
- Binderholz (USA)
- KLH (USA, CAN)
- Kalesnikoff (USA, CAN)
- Nordic Structures (USA, CAN)
- Mercer Mass Timber
- SmartLam
- Sterling Structural
- Superstructures listed in Lignatec Edition 32 "Cross-Laminated Timber of Swiss Production"
By importing a structure from the layer structure library, all relevant parameters are adopted automatically. The library is continually updated.
Compared to the RF‑SOILIN add-on module (RFEM‑5), the following new features have been added to the Geotechnical Analysis add-on for RFEM 6:
- Creation of the layered soil as a 3D model from the entirety of the defined soil samples
- Recognized material law according to Mohr-Coulomb for soil simulation
- Graphical and tabular output of stresses and strains at any depth of the soil
- Optimal consideration of the soil-structure interaction on the basis of an overall model
For joint components, you can check whether the stability failure is relevant. This requires the Structure Stability add-on for RFEM 6.
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.
The Concrete Design add-on allows you to perform the seismic design of reinforced concrete members according to EC 8. This includes, among other things, the following functionalities:
- Seismic design configurations
- Differentiation of the ductility classes DCL, DCM, DCH
- Option to transfer the behavior factor from a dynamic analysis
- Check of the limit value for the behavior factor
- Capacity design checks of "Strong column - weak beam"
- Detailing and particular rules for curvature ductility factor
- Detailing and particular rules for local ductility
You can select several methods that are available for the eigenvalue analysis:
- Direct Methods
- The direct methods (Lanczos [RFEM], roots of characteristic polynomial [RFEM], subspace iteration method [RFEM/RSTAB], and shifted inverse iteration [RSTAB]) are suitable for small to medium-sized models. You should only use these fast solver methods if your computer has a larger amount of memory (RAM).
- ICG Iteration Method (Incomplete Conjugate Gradient [RFEM])
- In contrast, this method only requires a small amount of memory. Eigenvalues are determined one after the other. It can be used to calculate large structural systems with few eigenvalues.
Use the Structure Stability add-on to perform a nonlinear stability analysis using the incremental method. This analysis delivers close-to-reality results also for nonlinear structures. The critical load factor is determined by gradually increasing the loads of the underlying load case until the instability is reached. The load increment takes into account nonlinearities such as failing members, supports and foundations, and material nonlinearities. After increasing the load, you can optionally perform a linear stability analysis on the last stable state in order to determine the stability mode.
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 soil solids that you want to analyze are summarized in soil massifs.
Use the soil samples as a basis for a definition of the respective soil massif. This way, the program allows for user-friendly generation of the massif, including the automatic determination of the layer interfaces from the sample data, as well as the groundwater level and the boundary surface supports.
Soil massifs provide you with the option to specify a target FE mesh size independently of the global setting for the rest of the structure. You can thus consider the various requirements of the building and soil in the entire model.