Did you know that you can also display the moment-axial force interaction diagrams (M‑N diagrams) graphically? This allows you to display the cross-section resistance in the case of an interaction of a bending moment and an axial force. In addition to the interaction diagrams related to the cross-section axes (My‑N diagram and Mz‑N diagram), you can also generate an individual moment vector to create an Mres‑N interaction diagram. You can display the section plane of the M‑N diagrams in the 3D interaction diagram. The program displays the corresponding value pairs of the ultimate limit state in a table. The table is dynamically linked to the diagram so that the selected limit point is also displayed in the diagram.
In 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.
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.
Design 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.
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.
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.
Reinforced concrete usually answers the question "How much can you carry?" simply with "Yes". Nevertheless, you need a three-dimensional moment-moment-axial force interaction diagram for the graphical output of the ultimate limit state of reinforced concrete cross-sections. The Dlubal structural analysis software offers you just that.
With the additional display of the load action, you can easily recognize or visualize whether the limit resistance of a reinforced concrete cross-section is exceeded. Since you can control the diagram properties, you can customize the appearance of the My-Mz-N diagram to suit your needs.
Do you work with the structural components consisting of slabs? In that case, you have to perform the shear force design with the requirements of punching shear design, for example, according to 6.4, EN 1992‑1‑1. In addition to floor slabs, you can also design foundation slabs in this way.
In the Ultimate Configuration for concrete design, you can define the punching design parameters for the selected nodes.
Time-dependent concrete properties, such as creep and shrinkage, are very important for your calculation. You can define them directly for the material in the structural analysis program. In the input dialog box, the time course of the creep or shrinkage function is displayed to you graphically. You can easily select the modification of the applied concrete age, for example, due to a temperature treatment.
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.
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, when selected, is applied to your model
In the Template, there are connections from 3 general categories: Rigid, Pinned, Truss
Automatic adaptation of the connection geometry, even if the members are subsequently edited, due to the relative relation of the components to each other
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.
Depending on the axial force N, you can generate a moment curvature line for any moment vector. The program also shows you the value pairs of the displayed diagram in a table. Furthermore, you can activate the secant stiffness and tangent stiffness of the reinforced concrete cross-section, belonging to the moment curvature diagram, as an additional diagram.
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.
The "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).
You can display the existing stresses and strains of a concrete cross-section and the reinforcement as a 3D stress image or 2D graphic. Depending on which results do you select in the result tree of the design details, the stresses or strains are displayed to you in the defined longitudinal reinforcement under the load actions or the limit internal forces.
In the Concrete Design add-on, you can design any RSECTION cross-section. Define the concrete cover, shear force, and longitudinal reinforcement directly in RSECTION.
After importing the reinforced RSECTION cross-section into RFEM 6 or RSTAB 9, you can use it for design in the Concrete Design add-on.
You have the option to automatically design the existing surface reinforcement to cover the required reinforcement. You can also select whether to automatically define the reinforcement diameter or the member spacing.
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.
You can specify the shear and longitudinal reinforcement individually for each member. In this case, there are various templates available for entering the reinforcement.
You determine the deformation for members and surfaces, taking into account the cracked (state II) or non-cracked (state I) reinforced concrete cross-section. When determining the stiffness, you can consider "tension stiffening" between the cracks according to the design standard used.
Do you want to determine the biaxial bending resistance of a reinforced concrete cross-section? For this, you have to activate a moment-moment interaction diagram (My-Mz diagram) first. This My-Mz diagram represents a horizontal section through the three-dimensional diagram for the specified axial force N. Due to the coupling to the 3D interaction diagram, you can also visualize the section plane there.
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: