Global 3D calculation of the global model, where the slabs are modeled as a rigid plane (diaphragm) or as a bending plate
Local 2D calculation of the individual floors
After the calculation, the results of the columns and walls from the 3D calculation and the results of the slabs from the 2D calculation are combined in a single model. This means that there is no need to switch between the 3D model and the individual 2D models of the slabs. The user only works with one model, saves valuable time, and avoids possible errors in the manual data exchange between the 3D model and the individual 2D ceiling models.
The vertical surfaces in the model can be divided into shear walls and opening lintels. The program automatically generates internal result members from these wall objects, so they can be designed as members according to any standard in the Concrete Design add-on.
With Dlubal Software, you always have an overview, regardless of whether your projects are from the reinforced concrete, steel, timber, aluminum, or other industry. The program clearly displays the design check formulas used in your design (including a reference to the used equation from the standard). These design check formulas can also be included in the printout report.
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.
Have you activated the Building Model add-on? Very good! This allows you to display the center of rigidity in tabular and graphical form. Use it for your dynamic analysis, for example.
As you've already learned, the results of a Modal Analysis load case are displayed in the program after a successful calculation. You can thus immediately see the first mode shape graphically or as an animation. You can also easily adjust the representation of the mode shape standardization. Do that directly in the Results navigator, where you have one of four options for the visualization of the mode shapes available for the selection:
Scaling the value of the mode shape vector uj to 1 (considers the translation components only)
Selecting the maximum translational component of the eigenvector and setting it to 1
Considering the entire eigenvector (including the rotation components), selecting the maximum, and setting it to 1
Setting the modal mass mi for each mode shape to 1 kg
You can find a detailed explanation of the mode shape standardization in the OnlineManual here.
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.
Is the calculation finished? The results of the modal analysis are then available both graphically and in tables. Display the result tables for the load case or the load cases of the modal analysis. Thus, you can see the eigenvalues, angular frequencies, natural frequencies, and natural periods of the structure at first glance. The effective modal masses, modal mass factors, and participation factors are also clearly displayed.
The design of cold-formed steel members according to the AISI S100-16 / CSA S136-16 is available in RFEM 6. Design can be accessed by selecting “AISC 360” or “CSA S16” as the standard in the Steel Design Add-on. “AISI S100” or “CSA S136” is then automatically selected for the cold-formed design.
RFEM applies the Direct Strength Method (DSM) to calculate the elastic buckling load of the member. The Direct Strength Method offers two types of solutions, numerical (Finite Strip Method) and analytical (Specification). The FSM signature curve and buckling shapes can be viewed under Sections.
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.
Is your goal to determine the number of mode shapes? The program offers you two methods for this. On the one hand, you can manually define the number of the smallest mode shapes to be calculated. In this case, the number of available mode shapes depends on the degrees of freedom (that is, the number of free mass points multiplied by the number of directions in which the masses act). However, it is limited to 9999. On the other hand, you can set the maximum natural frequency the way that the program determined the mode shapes automatically until reaching the natural frequency set.
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.
The governing component temperature at the time of analysis can be determined for the fire resistance design automatically using the input. In this case, you can follow the temperature curve in detail as a function of timeby displaying the temperature-time diagram.
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)
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
The Torsional Warping (7 DOF) add-on provides you with numerous new possibilities. For example, you can perform the calculation of member structures in RFEM and RSTAB, taking into account the cross-section warping. You can consider the resulting internal forces (N, Vu, Vv, Mt,pri, Mt,sec, Mu, Mv, Mω) in the equivalent stress analysis of the steel design. Please note: This feature is currently not available for the design standards AISC 360‑16 and GB 50017.
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.
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.
Do you want to perform a stability analysis in the Steel Design add-on? Then it is absolutely necessary to define the effective lengths. To do this, define the nodal supports and effective length factors in the input dialog box. For easy documentation and a comprehensible check of the entries, you can also graphically display the nodal supports and the resulting segments with the corresponding effective length factor in the work window of RFEM/RSTAB.
You can find the serviceability limit state design checks in the result tables of the Steel Design add-on. You can display the design results with all the details at each location of the designed members. Furthermore, graphics are available for you with the result diagrams of the design ratios. This gives you a good overview.
You can also integrate all result tables and graphics into the global printout report of RFEM/RSTAB as a part of the steel design results. Thus, you can display and document the deformations of the entire structure as a part of the RFEM/RSTAB functionality independent of the add-on.
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.
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)
The calculation of masonry is carried out in compliance with the nonlinear-plastic material law. If the load at any point is higher than the possible load to be resisted, redistribution takes place within the system. This have the simple purpose of restoring the equilibrium of forces. With the successful completion of the calculation, the stability analysis is provided.
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.
In RFEM/RSTAB, you have the option to generate and then calculate the load or result combinations required for the serviceability limit state. You can select these design situations for the deflection analysis in the Steel Design add-on. The calculated deformation values are determined accordingly at each location of a member, depending on the specified precamber and reference system. Finaly, you can compare these deformation values with the limit values.
Did you know? You can specify the deformation limit value individually for each structural component in Serviceability Configuration. Define the maximum deformation depending on the reference length as the allowable limit value. By defining design supports, you can segment the components in order to determine the corresponding reference length automatically for each design direction.
Based on the position of the assigned design supports, the distinction between beams and cantilevers is made automatically so the limit value can be determined accordingly.
Please note that when connecting tension-loaded components with bolted connections, you need to consider the cross-section reduction due to the bolt holes in the ultimate limit state design. But don't worry, this can be easily done in the program. In the Steel Design add-on, you can enter a member local section reduction – and that's it. You can enter the reduction of the cross-section as an absolute value or as a percentage of the total area at all relevant locations.
Using the "Load Transfer Only" story type, you can consider slabs without stiffness effect in and out of the plane in the Building Model add-on. This element type collects the loads on the slab and transfers them to the supporting elements of a 3D model. Thus, you can simulate secondary components, such as grillage and similar load distribution elements, without any further effect in the 3D model.
Have you already discovered the tabular and graphical output of masses in mesh points? That's right, this is also part of the modal analysis results in RFEM 6. This way, you can check the imported masses that depend on various settings of the modal analysis. They can be displayed in the Masses in Mesh Points tab of the Results table. The table provides you with an overview of the following results: Mass - Translational Direction (mX, mY, mZ), Mass - Rotational Direction (mφX, mφY, mφZ), and the Sum of Masses. Would it be best for you to have a graphical evaluation as quickly as possible? Then you can also graphically display the masses in mesh points.
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
Was your design successful? Then just sit back and relax. You benefit from the numerous functions in RFEM also here. The program gives you the maximum stresses of the masonry surfaces, whereby you can display the results in detail at each FE mesh point.
Moreover, you can insert sections in order to carry out a detailed evaluation of the individual areas. Use the display of the yield areas to estimate the cracks in the masonry.