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 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".
In the Steel Joints add-on, you have this option to consider the preloaded bolts in the calculation of all components.
You can easily activate the prestress using the check box in the bolt parameters, and it has an impact on the stress-strain analysis as well as the stiffness analysis.
In the Steel Joints add-on, you can determine the initial stiffness Sj,ini according to Eurocode and AISC. This can be done for selected members with reference to the internal forces N, My, and Mz.
In the Members tab of the input dialog box of the Steel Joints add-on, you can select the desired internal forces via a checkbox. Multiple selection is possible. For these internal forces, the stiffness analysis is carried out with a positive and a negative sign.
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.
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:
The new steel sections according to the latest CISC Handbook (12th edition) are available in RFEM 6. The sections are listed in the Standardized library. In the filter, select “Canada” for the region and “CISC 12” for the standard. Alternatively, the section name can be directly entered in the search box located at the bottom of the dialog box.
Consideration of 7 local deformation directions (ux, uy, uz, φx, φy, φz, ω) or 8 internal forces (N, Vu, Vv, Mt,pri, Mt,sec, Mu, Mv, Mω) when calculating member elements
Usable in combination with a structural analysis according to linear static, second-order, and large deformation analysis (imperfections can also be taken into account)
In combination with the Stability Analysis add-on, allows you to determine critical load factors and mode shapes of stability problems such as torsional buckling and lateral-torsional buckling
Consideration of end plates and transverse stiffeners as warping springs when calculating I-sections with automatic determination and graphical display of the warping spring stiffness
Graphical display of the cross-section warping of members in the deformation
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.
Due to the integrated RF-/STEEL Warping Torsion module extension, it is possible to perform the design according to Design Guide 9 in RF-/STEEL AISC.
The calculation is performed with 7 degrees of freedom according to the warping torsion theory and enables a realistic stability design, including consideration of torsion.
The determination of the critical buckling moment is carried out in RF-/STEEL AISC by using the eigenvalue solver which allows an exact determination of the critical buckling load.
The eigenvalue solver shows a display window of the eigenvalue graphics, which enables checking of the boundary conditions.
In STEEL AISC, it is possible to consider lateral intermediate supports at any location. For example, it is possible to stabilize only the upper flange.
Furthermore, user-defined lateral intermediate supports can be assigned; for example, single rotational springs and translational springs at any location at the cross-section.
The first result window shows the maximum design ratios with the corresponding design of each designed load case, load combination, or result combination.
The other result windows list all detailed results sorted by specific subject in extendable tree menus. All intermediate results along the members can be displayed at any location. In this way, you can easily retrace how the module has performed the individual designs.
The complete module data are part of the RFEM/RSTAB printout report. You can select the report contents and extent specifically for the individual designs.
First, it is necessary to decide whether to perform design according to ASD or LRFD. Then, you can enter the load cases, load combinations, and result combinations to be designed. Load combinations according to ASCE 7 can be generated either manually or automatically in RFEM/RSTAB.
In the next steps, you can adjust presettings of lateral intermediate supports, effective lengths, and other standard-specific design parameters, such as the modification factor Cb for lateral-torsional buckling or the shear lag factor. In the case of continuous members, it is possible to define individual support conditions and eccentricities of each intermediate node of single members. A special FEA tool determines critical loads and moments required for the stability analysis.
In connection with RFEM/RSTAB, it is possible to apply the Direct Analysis Method taking into account the influence of the general calculation according to the second-order analysis. In this way, you avoid using special enlargement factors.
Design of members and sets of members for tension, compression, bending, shear, combined internal forces, and torsion
Stability analysis of buckling and lateral-torsional buckling
Automatic determination of critical buckling loads and critical buckling moments for general load applications and support conditions by means of a special FEA program (eigenvalue analysis) integrated in the module
Alternative analytical calculation of the critical buckling moment for standard situations
Optional application of discrete lateral supports to beams and continuous members
Automatic cross-section classification (compact, noncompact, and slender)
Serviceability limit state design (deflection)
Cross-section optimization
A wide range of available cross-sections, such as rolled I-sections; channel sections; T-sections; angles; rectangular and circular hollow sections; round bars; symmetrical and asymmetrical, parametric I-, T-, and angle sections; double angles
Clearly arranged input and result windows
Detailed result documentation including references to design equations of the used standard
Various filter and sorting options of results, including result lists by member, cross-sections, and x-location, or by load case, load combination, and result combination
Result table of member slenderness and governing internal forces
Since RF-/STEEL Warping Torsion is fully integrated in RF-/STEEL AISC and RF‑/STEEL EC3, the data are entered in the same way as for the usual design in these modules. It is only necessary to select the option "Perform warping analysis" in the Details dialog box, tab Warping Torsion (see the figure on the right). You can also define the maximum number of iterations in this dialog box.
The warping torsion analysis is performed for sets of members in RF-/STEEL AISC and RF‑/STEEL EC3. You can define boundary conditions such as nodal supports or member end releases for them. It is also possible to specify imperfections for the nonlinear calculation.
The results of warping torsion analysis are displayed in RF-/STEEL AISC and RF-/STEEL EC3 in the usual way. Among other results, the corresponding result windows include the critical warping and torsional values, internal forces, and design summary.
The graphical display of mode shapes (incl. warping) enables a realistic assessment of buckling behavior.