In the Geotechnical Analysis add-on, the Hoek-Brown material model is available. The model shows linear-elastic ideal-plastic material behavior. Its nonlinear strength criterion is the most common failure criterion for stone and rocks.
You can enter the material parameters using
Rock parameters directly, or alternatively via
GSI classification.
Detailed information about this material model and the definition of the input in RFEM can be found in the respective chapter Hoek-Brown Model of the online manual for the Geotechnical Analysis add-on.
For calculation diagrams, the "2D | Hinge" is available. These hinge diagrams show the hinge response of load situations for nonlinear hinges.
For calculations with several load situations, such as is the case with pushover analyzes and time history analysis, you can evaluate the state of the hinge in each load step.
The Time History Analysis add-on provides you with accelerograms for the calculation. This extension allows for dynamic structural analysis of the acceleration-time diagrams.
There is an extensive library of earthquake records available for you, but you can also enter or import your own diagrams. The time history analysis is performed using the modal analysis or the linear implicit Newmark analysis.
In RFEM 6 and RSTAB 9, you can export line graphics to the SVG format (vector graphics).
SVG stands for Scalable Vector Graphics and is an XML-based file format for displaying two-dimensional vector graphics. These vector graphics can be scaled without loss. It is possible to edit the SVG files using text editors, embed them on websites, and open them in the usual browsers.
The "Spring" member type is used to simulate linear and nonlinear spring properties via a linear object. This input function helps you to model the stiffness specifications in the force/displacement unit.
The time history analysis is performed with the modal analysis or the linear implicit Newmark analysis. The time history analysis in this add-on is limited to linear structural systems. Although the modal analysis represents a fast algorithm, it is necessary to use a certain number of eigenvalues to ensure the required accuracy of results.
The implicit Newmark analysis is a very precise method, independent of the number of eigenvalues used, but requires sufficient small time steps for the calculation.
Several modeling tools are available for elements in building models:
Vertical line
Column
Wall
Beam
Rectangular floor
Polygonal floor
Rectangular floor opening
Polygonal floor opening
This feature allows you to define the element on the ground plane (for example, with a background layer) with the associated multiple element creation in space.
The Concrete Design add-on allows you to design fiber-reinforced concrete components according to the guideline "DAfStb Steel Fiber-Reinforced Concrete".
You can use this option for the design according to EN 1992‑1‑1. The design according to the DAfStb guideline is carried out once the concrete of the "Fiber Concrete" type has been assigned to the reinforced structural component.
You can simulate the static friction effects between two supporting components along a line using the "Friction" nonlinearity in the Line Release Type.
The "Building Grid" guide object supports you in the design of your structure. It features intuitive grid coordinate input and grid line labeling.
You can quickly place grids in space and label them by specifying a graded coordinate code. The grid line end modification allows you to optimize the grid appearance. Furthermore, a preview helps you to define the building grid.
You can import STEP files into RFEM 6. The data is directly converted into the native RFEM model data.
The STEP format represents a standard interface initiated by ISO (ISO 10303). In the geometry description, all shapes relevant for RFEM (line, surface, and solid models) can be integrated by the CAD data models.
Note: This format is not to be confused with DSTV interfaces, which also use the file extension *.stp.
Use the "Import Support Reactions" Load Wizard in RFEM 6 and RSTAB 9 to easily transfer reaction forces from other models. The wizard allows you to connect all or several nodal and line loads of different models with each other in a few steps.
The load transfer from load cases and load combinations can be carried out automatically or manually. It's necessary that the models are saved in the same Dlubal Center project.
The "Import Support Reactions" load wizard supports the concept of positional statics and allows you to digitally connect the individual positions.
Lines can be imported into RFEM either as lines or members. The names of layers are adopted as the cross-section names, and the first material from the predefined materials is assigned. However, if the section of the Dlubal cross-section library and the material are recognized from the layer name, they are adopted as well.
Did you know? In the Design Supports, you can now define fully threaded screws as transversal compression stiffening elements for the "Compression Perpendicular to Grain" design. In this case, the pressing-in and buckling of the bolts is analyzed.
Moreover, the design shear resistance is checked in the plane of the screw tip. The angle of dispersal can be considered as linear under 45° or nonlinear (according to Bejtka, I. (2005). Verstärkung von Bauteilen aus holz mit vollgewindeschrauben. KIT Scientific Publishing.).
Create guidelines with or without a description for the display of a building grid! You can lock the guideline position to prevent accidental movement of them, for example.
Furthermore, you can glue the guidelines to nodes in order to move the glued nodes as well. That makes your work a lot easier!
Consideration of nonlinear component behavior using plastic standard hinges for steel (FEMA 356, EN 1998‑3) and nonlinear material behavior (masonry, steel - bilinear, user-defined working curves)
Direct import of masses from load cases or combinations for the application of constant vertical loads
User-defined specifications for the consideration of horizontal loads (standardized to a mode shape or uniformly distributed over the height of the masses)
Determination of a pushover curve with selectable limit criterion of the calculation (a collapse or limit deformation)
Transformation of the pushover curve into the capacity spectrum (ADRS format, single degree of freedom system)
Bilinearization of the capacity spectrum according to EN 1998‑1:2010 + A1:2013
Transformation of the applied response spectrum into the required spectrum (ADRS format)
Determination of target displacement according to EC 8 (the N2 method according to Fajfar 2000)
Graphical comparison of the capacity and required spectrum
Graphical evaluation of the acceptance criteria of predefined plastic hinges
Result display of the values used in the iterative calculation of the target displacement
Access to all results of the structural analysis in the individual load levels
During the calculation, the selected horizontal load is increased in load steps. A static nonlinear analysis is carried out for each load step until reaching the specified limit condition.
The results of the pushover analysis are extensive. On one hand, the structure is analyzed for its deformation behavior. This can be represented by a force-deformation line of the system (a capacity curve). On the other hand, the response spectrum effect can be displayed in the ADRS display (Acceleration-Displacement Response Spectrum). The target displacement is automatically determined in the program based on these two results. The process can be evaluated graphically and in tables.
The individual acceptance criteria can then be graphically evaluated and assessed (for the next load step of the target displacement, but also for all other load steps). The results of the static analysis are also available for the individual load steps.
This function provides you with the option to adopt reaction forces from other models as nodal and line loads.
The option not only transfers the reaction load as an action, but digitally couples the support load of the original model with the load size of the target object. The subsequent changes in the original model are automatically adopted in the target model.
This technology supports the concept of positional statics and allows you to digitally connect the individual positions of the same Dlubal Center project.
Would you like to create a cross-section from the import of a DXF file? It's very easy. You have the following options:
Create elements automatically
Use DXF template lines as centerlines of elements with a defined thickness
Do you select the option to create the elements automatically? In that case, the program creates the elements and the associated parts for you from the contour of the outline. It only creates the elements not exceeding a definable maximum thickness. Your cross-section geometry is available as a centroidal axis model? Then use DXF template lines as centerlines of elements with a defined thickness. Defining a thickness that is assigned equally to all elements. Do you miss the "Create elements automatically" and "Create elements on lines" functions? Don't worry, both are also available in the "Edit" menu under "Manipulation".
What are plastic hinges? Very simple – plastic hinges according to FEMA 356 help you to create pushover curves. These are nonlinear hinges with preset yield properties and acceptance criteria for steel members (Chapter 5 of FEMA 356).
You probably already know that node, line, and surface releases are used to define transfer conditions between objects. For example, you can release members, surfaces, and solids from a line. It is also easily possible for the releases to have nonlinear properties, such as "Fixed if positive n", "Fixed if negative n", and so on.
Use the Edit Nodes function to adjust the node type with the automatic specification of all necessary secondary properties. You also have the option to transfer a node to a line or to a member, or to place it between two nodes and two points.
Did you know that you can extrude surfaces into members? In this case, the program assigns a desired member property to the lines generated by the extrusion. A few clicks later, you are already at the desired result.
Extruding surfaces into a casing is also possible without any problems. Place the desired surface properties between the boundary lines of the surface and the copied lines. The program does the rest for you.
RFEM 6 and RSTAB 9 support the ergonomically optimized utilization of a mobile 3D mouse by 3Dconnexion.
With a 3D mouse, you can simultaneously move, zoom, and flip a 3D model on the screen beyond the use of a regular mouse. The 3D mouse complements the conventional computer mouse and is operated with your free hand. Therefore, you can streamline the workflow if you operate a 3D mouse with your non-dominant hand, in addition to the normal mouse.