Using the "Damper" member type, you can define a damping coefficient, a spring constant, and a mass. This member type extends the possibilities within the Time History Analysis.
With regard to viscoelasticity, the "Damper" member type is similar to the Kelvin-Voigt model, which consists of the damping element and an elastic spring (both connected in parallel).
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.
In the Modal Analysis add-on, you have the option to automatically increase the sought eigenvalues until reaching a defined effective modal mass factor. All translational directions activated as masses for the modal analysis are taken into account.
Thus, it is possible to easily calculate the required 90% of the effective modal mass for the response spectrum method.
You can open the cross-sections in RSECTION using a direct connection, modify them there, and transfer them back to RFEM/RSTAB. Both RSECTION cross-sections and library cross-sections, with the exception of elliptical, semi-elliptical and virtual joists, can be opened and modified directly in RSECTION by clicking a button.
For example, you can thus adjust the reinforcement layout of user-defined RSECTION cross-sections directly in a local RSECTION environment in RFEM/RSTAB. This feature is currently only available for cross-sections with a uniform distribution type. The shear and longitudinal reinforcement defined for library cross-sections is not imported into RSECTION.
The modal relevance factor (MRF) can help you to assess to which extent specific elements participate in a specific mode shape. The calculation is based on the relative elastic deformation energy of each individual member.
The MRF can be used to distinguish between local and global mode shapes. If multiple individual members show significant MRF (for example, > 20%), the instability of the entire structure or a substructure is very likely. On the other hand, if the sum of all MRFs for an eigenmode is around 100%, a local stability phenomenon (for example, buckling of a single bar) can be expected.
Furthermore, the MRF can be used to determine critical loads and equivalent buckling lengths of certain members (for example, for stability design). Mode shapes for which a specific member has small MRF values (for example, < 20%) can be neglected in this context.
The MRF is displayed by mode shape in the result table under Stability Analysis → Results by Members → Effective Lengths and Critical Loads.
The combination wizard provides you with the option to consider more than one initial state. RFEM and RSTAB allow you to specify different initial states (prestress, form-finding, strain, and so on) for the target combinations in the combinatorics.
You can thus, for example, generate load states on the basis of a form-finding analysis with varying imperfections.
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 Concrete Design add-on provides you with the option to perform the simplified fire resistance design according to EN 1992‑1‑2 for columns (Section 5.3.2) and beams (Section 5.6).
The following design checks are available for the simplified fire resistance design:
Columns: Minimum cross-sectional dimensions for rectangular and circular sections according to Table 5.2a as well as Equation 5.7 for calculating time of fire exposure
Beams: Minimum dimensions and center distances according to Table 5.5 and Table 5.6
You can determine the internal forces for the fire resistance design according to two methods.
1 Here, the internal forces of the accidental design situation are included directly into the design.
2 The internal forces of the design at normal temperature are reduced by the factor Eta,fi (ηfi), then used in the fire resistance design.
Furthermore, it is possible to modify the axis distance according to Eq. 5.5.
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.
In the design add-ons (such as Steel Design, Timber Design, and so on), you can optimize cross-sections.
The optimization can be performed, for example, for standard cross-sections of a series, or for the width, height, and so on, in the case of parametric cross-sections.
The Timber Design add-on for RFEM 6 / RSTAB 9 is multi-purpose and combines a large number of additional elements. [*S16332764*]
Timber Design Add-on for RFEM 6
With the Concrete Design add-on, you can perform the fatigue design of members and surfaces according to EN 1992‑1‑1, Chapter 6.8.
For the fatigue design, you can optionally select two methods or design levels in the design configurations:
Design Level 1: Simplified design according to 6.8.6 and 6.8.7(2): The simplified design is performed for frequent action combinations according to EN 1992‑1‑1, Chapter 6.8.6 (2), and EN 1990, Eq. (6.15b) with the traffic loads relevant in the serviceability state. A maximum stress range according to 6.8.6 is designed for the reinforcing steel. The concrete compressive stress is determined by means of the upper and lower allowable stress according to 6.8.7(2).
Design Level 2: Design of damage equivalent stress acc. to 6.8.5 and 6.8.7(1) (simplified fatigue design): The design using damage equivalent stress ranges is performed for the fatigue combination according to EN 1992‑1‑1, Chapter 6.8.3, Eq. (6.69) with the specifically defined cyclic action Qfat.
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
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.
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.
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.
For design supports, you can take into account a shear force reduction. This allows you to perform the shear design with the governing shear force at a distance of the beam height from the support edge.
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.
When using multiple identical blocks in a model, you can assign a reference block to the selected blocks.
If you then change parameters such as geometry, material, and cross-section of the reference block, these are automatically adopted for the "child blocks".
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!