When using a welded profile, weld seam verification can also be carried out in RF-/STEEL EC3 as part of the design. The program performs the typical designs according to EN 1993‑1‑8.
In RFEM, you have the option to create and analyze cables using sheaves. For this, use the "Cable on Pulleys" member type. It is ideal for pulley systems, where the longitudinal forces are transferred via sheaves.
Sometimes, a detailed examination is needed of problematic areas of a joint or the stiffness of a frame joint. The following tips can help you with this. As an example, a frame joint was modeled using RF‑FRAME‑JOINT Pro and members, and used as a basis.
A modell check allows you to find overlapping members, among other things. However, this targeted selection could cause some minor problems. Therefore, there is a selection window now available, which appears when you click on one of the elements. This appears by clicking on one of the elements. Additional information helps you to select the correct member.
The local coordinate system of a member is particularly important when defining member end releases and member nonlinearities. The definitions follow the orientation of the axes. You can temporarily adjust the visibility of these member axes by means of preselection.
When defining real support conditions, it is always necessary to combine linear and nonlinear support conditions. This way, a beam resting on a wall can transfer compression forces to the wall and the line support (wall) will not take over the lifting forces. These forces should be carried by screws, for example, which are defined as a linear nodal support.
In RFEM and RSTAB, you can create nodes not only by means of coordinates, but also by means of existing nodes. You can use the "Node Between Two Points" function to create a node located on an imaginary line connecting two nodes. You can enter the distance as a percentage or according to the relative lengths.
The equivalent loads determined in RF-TENDON due to prestress are transferred in RFEM as member loads or as line loads. A member load is used for member types with their own stiffness; a line load is used for member types without their own stiffness. In order to understand which values of the concentrated loads are to be transferred from RF‑TENDON to RFEM, you should use the following display settings: ~ Reference of the loads to the global coordinate system (GCS), ~ Load display: "Point"
In RFEM, if you want to display a curved geometry (preferably in one continuous line), you can use splines or NURBS, for example. When modeling, you should pick the individual nodes one after another. If a mistake is made, you can go back using the special Undo function in the "New Spline Line" window. Thus, it is not necessary to enter the entire continuous line again.
Diagonals of double angles are used for pipe bridge construction and for truss girders, among other things. They are usually subjected to tension, but it is necessary to transfer them in smaller compression forces with regard to the load application. In the case of slender diagonals in particular, you should also consider the bending due to self‑weight.
With the latest version of CONCRETE and RF-CONCRETE Members, it is possible to perform shear design for the connection of compression and tension flanges on a T-beam web.
Just as in the RFEM Display Navigator, you can set the distribution of internal forces in surfaces in RF‑STEEL Surfaces. Since deformations are always the result of the FEM calculation, the corresponding forces will be recalculated. This means that the internal forces on an FEM element are calculated depending on the composition (triangular or square) in three or four places. In order to obtain continuous internal forces and thus a smoothed distribution, these internal forces have to be interpolated. Interpolation is done by selecting the "Distribution of internal forces" option in the surfaces.
In RFEM and RSTAB, the internal forces of individual load combinations are determined according to the second-order analysis by default. If you use the RF‑CONCRETE add‑on module for stability analysis of reinforced concrete columns, you can change the calculation method of LCs to the linear static analysis, since the effects of the second‑order analysis are already considered in the calculation according to the model column method in RF‑CONCRETE Columns (nominal curvature method).
In RF‑LAMINATE, you can also design curved quadrangle surfaces. In the example in the figure, the cross-laminated timber layers of a chair are designed.
It is often necessary to adjust the FE mesh of surface elements to the geometric structure. RFEM provides various options for this. For example, the FE axis can be rotated around a point, aligned in the direction of a point, or oriented to a user-defined coordinate system. Another option is the direction parallel to a line, and in this case in particular, it is possible to enter or select several lines.
When calculating the surface reinforcement in RF-CONCRETE Surfaces, the result values for both surface sides +/- z are available. If you are unsure which side of a surface is the positive or the negative z side, you can hide the local coordinate system of each surface in the RFEM Project Navigator - Display under "Model" → "Surfaces" → "Surface Axis Systems x,y,z". In the case of complex structures, this can quickly become confusing. Displaying multiple axis systems makes it difficult to recognize the incorrect direction of a surface, for example (see the figure on the top).
In addition to the standard functions, the input tables of the main program have block functions. With these functions, you can edit the data in the selected rows and columns of the table in one step.
In RF‑/JOINTS Timber, you can remove an individual dowel from the calculation, thus creating any dowel layout. The calculation disregards these removed dowels for the ultimate limit state design, as well as for the net timber cross‑section analysis and the rotational spring stiffness determination.
NCI to DIN EN 1993‑6, Part 2.3.1 allows reductions of dynamic coefficients for values ≧ 1.1. Therefore, you can use these reduced support loads for designing support and hanger structures. In CRANEWAY, if you select National Annex "DIN" and dynamic coefficients ≧ 1.1, the reduction is considered automatically.
You can display the results on surfaces in a graphic. It may be useful to use the values on surfaces. Depending on the requirements, you can reduce the number of values considerably or adjust them to cover the entire structure. However, it is important to display the values that represent the local extreme values. In addition, it is necessary to determine the local extremes. This can be done by right-clicking this function in the Navigator.
In order to design longitudinal reinforcement for the serviceability limit state, it is necessary to enable this function. This is possible in Window 1.1 General Data under the "Serviceability Limit State" tab. After you select the "Analytical..." method of checking, you can select the corresponding additional options in the section for determining the longitudinal reinforcement of the "Settings of Analytical Method of Serviceability Limit State Design" window.
If it is impossible to transfer all internal forces from one surface to the next, you have to arrange a line hinge. To do this, use the "Edit Surface" dialog box, "Hinges" tab.
In RF-/JOINTS Steel - Pinned, it is possible to design connections without a supporting structure (for example, columns). In this case, the beam is connected to an anchor plate. How is this kind of connection defined?
In RF-/JOINTS Timber - Steel to Timber, you can consider the eccentricities of a connection during the calculation. The figure shows different internal forces without consideration of the eccentricity (above) and withn consideration of the eccentricity (below).
In RF-CONCRETE Surfaces, you can use the "Filter Points" function when evaluating results by points. This filter function allows for a user-defined group of points that can be defined in the result window. You can select the filter in Window 2.3 Required Reinforcement by Points, among others.
When calculating the surface reinforcement in RF-CONCRETE Surfaces, the result values for both surface sides +/- z are available. A previous post describes how to display the local surface sides in RFEM.
Dlubal Software Programs provide a materials library. This library covers almost all materials commonly used in civil engineering, including the corresponding parameters for calculation and design.