In the Timber Design add-on for RFEM, you can design members as well as surfaces according to Eurocode 5, SIA 265 (Swiss standard), CSA O86 (Canadian standard), or ANSI/AWC NDS (American standard); for example, cross-laminated timber, glued-laminated timber, softwood, mass timber, and so on.
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 this 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 here:
Online Manual
.
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.
For timber surfaces with the "Constant" thickness type, the crack factor kcr and thus the negative influence of cracks on the shear capacity is taken into account.
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.
As you probably know, the design checks for the selected members are carried out, taking into account the defined charring time. All necessary reduction factors and coefficients are stored accordingly in the program and are taken into account when determining the load-bearing capacity. That saves you a lot of work.
The effective lengths for the equivalent member design are taken directly from the strength entries. You do not have to enter them again.
After completing the design, the program presents the fire resistance design checks clearly and with all result details. This allows you to follow the results completely transparently. The results also contain all the required parameters, so you can determine the component temperature at the design time.
In addition to all these features, the program allows you to integrate all result tables and graphics, including the ultimate and serviceability limit state results,into the global printout report of RFEM/RSTAB as a part of the steel design results.
In RFEM and RSTAB, you can design members with the "Laminated Veneer Lumber" material type. The following manufacturers are available:
Pollmeier (Baubuche)
Metsä (Kerto LVL)
STEICO
Stora Enso
In the ultimate configuration, you can consider strength coefficients for increasing the strengths. The coefficients reducing the strengths are automatically taken into account regardless of this. Try it now!
You can graphically evaluate result sections for the timber surface design. This can be done in the RFEM graphic as well as in the result history window. The sections can be placed at any location in order to evaluate the design results in detail.
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 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
Design of tension, compression, bending, shear, torsion, and combined internal forces
Consideration of a notch
Design of compression perpendicular to the grain on the end and intermediate supports with (EC 5) and without reinforcement elements (fully threaded screws)
Optional shear force reduction at the support
Design of curved and tapered members
Consideration of higher strengths for similar components that are close together (factor ksys according to EN 1995‑1‑1, 6.6(1)‑(3))
Option to increase shear resistance for softwood timber according to DIN EN 1995‑1‑1:NA NDP to 6.1.7(2)
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
Determination of the equivalent member lengths for tapered members
Consideration of the lateral-torsional bracing position
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)
Your options in timber design are diverse. You can consider cut-to-grain angles, transverse tension stresses, and volume-dependent radii of curvature for tapered and curved members. To design the area of the grain cut, the strength is adjusted accordingly in the case of bending tension or bending pressure. In order to also allow you to perform a stability analysis with the equivalent member method, the height to determine the effective and lateral-torsional buckling lengths is set at a distance of 0.65 × h to the actual design point.
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.
Compared to the RF‑/TIMBER Pro add-on module (RFEM 5 / RSTAB 8), the following new features have been added to the Timber Design add-on for RFEM 6 / RSTAB 9:
In addition to Eurocode 5, other international standards are integrated (SIA 265, ANSI/AWC NDS, CSA O86, GB 50005)
Design of compression perpendicular to grain (support pressure)
Implementation of eigenvalue solver for determining the critical moment for lateral-torsional buckling (EC 5 only)
Definition of different effective lengths for design at normal temperature and fire resistance design
Evaluation of stresses via unit stresses (FEA)
Optimized stability analyses for tapered members
Unification of the materials for all national annexes (only one "EN" standard is now available in the material library for a better overview)
Display of cross-section weakenings directly in the rendering
Output of the used design check formulas (including a reference to the used equation from the standard)
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.
Here you have a free choice. You can perform the support pressure design at any point for the loading in the y- and z-directions of a cross-section. You are free to differentiate between inner and outer supports. A factor kc,90 for the pressure perpendicular to the grain can be user-defined (for example, 1.75 for glued-laminated timber). If allowed, the support length is increased automatically according to the standard specifications. This allows you to achieve a more efficient design with minimum effort.
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.
RFEM/RSTAB also provides a range of functions for the case of a fire. The program allows for the automatic generation of load and result combinations for the accidental design situation of fire design. The members to be designed with the corresponding internal forces are imported directly from RFEM/RSTAB. Also, all information about the material and cross-section is stored. You don't need to do anything else.
You only define the parameters relevant for the fire resistance design by assigning a fire resistance configuration to the members and surfaces to be designed. Moreover, you can also make further detailed settings, such as the definition of the fire exposure on one side up to all sides.
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.
You can be sure that costs are an important factor in the structural planning of any project. It is also essential to adhere to the provisions on emissions estimation. The two-part add-on Optimization & Costs/CO2 Emission Estimation makes it easier for you to find your way through the jungle of standards and options. It uses the artificial intelligence technology (AI) of the particle swarm optimization (PSO) to find the right parameters for parameterized models and blocks that guarantee the compliance with the usual optimization criteria. This add-on also estimates the model costs or CO2 emissions by specifying unit costs or emissions per material definition for the structural model. With this add-on, you are on the safe side.
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.).
Use the member cross-section reductions to consider the start, internal, or end notches of a beam. The beam reduction is thus taken into account in the calculation of the load-bearing capacity. However, this does not apply to the stiffness.
Did you use the eigenvalue solver of the add-on to determine the critical load factor within the stability analysis? If so, you can then display the governing mode shape of the object to be designed as a result. The eigenvalue solver is available here for the lateral-torsional buckling analysis, depending on the design standard used.
Dlubal Software just makes everything a little easier. The performed design checks of the design standard are displayed in a clear way. A design criterion is determined for each design check. Furthermore, the program deliver the design details displayed in a structured way, including the initial values, the intermediate results, and the final results. An information window in the design details shows you the calculation process with the applied formulas, standard sources, and results in great detail.
What happens when there is a downwind? The topside lateral-torsional bracing is not applied to reduce the effective lengths and lateral-torsional buckling lengths.
Did you know? You can easily define structural modifications in load cases of the Modal Analysis type. This allows you, for example, to individually adjust the stiffnesses of materials, cross-sections, members, surfaces, hinges, and supports. You can also modify stiffnesses for some design add-ons. Once you select the objects, their stiffness properties are adapted to the object type. In this way, you can define them in separate tabs.
Do you want to analyze the failure of an object (for example, a column) in the modal analysis? This is also possible without any problems. Simply switch to the Structure Modification window and deactivate the relevant objects.