- Automatic consideration of masses from self-weight
- Direct import of masses from load cases or load combinations
- Optional definition of additional masses (nodal, linear, or surface masses, as well as inertia masses) directly in the load cases
- Optional neglect of masses (for example, mass of foundations)
- Combination of masses in different load cases and load combinations
- Preset combination coefficients for various standards (EC 8, SIA 261, ASCE 7,...)
- Optional import of initial states (for example, to consider prestress and imperfection)
- Structure Modification
- Consideration of failed supports or members/surfaces/solids
- Definition of several modal analyses (for example, to analyze different masses or stiffness modifications)
- Selection of mass matrix type (diagonal matrix, consistent matrix, unit matrix), including user-defined specification of translational and rotational degrees of freedom
- Methods for determining the number of mode shapes (user-defined, automatic - to reach effective modal mass factors, automatic - to reach the maximum natural frequency - only available in RSTAB)
- Determination of mode shapes and masses in nodes or FE mesh points
- Results of eigenvalue, angular frequency, natural frequency, and period
- Output of modal masses, effective modal masses, modal mass factors, and participation factors
- Masses in mesh points displayed in tables and graphics
- Visualization and animation of mode shapes
- Various scaling options for mode shapes
- Documentation of numerical and graphical results in printout report
In the modal analysis settings, you have to enter all data that are necessary for the determination of the natural frequencies. These are, for example, mass shapes and eigenvalue solvers.
The Modal Analysis add-on determines the lowest eigenvalues of the structure. Either you adjust the number of eigenvalues or let them determined automatically. Thus, you should reach either effective modal mass factors or maximum natural frequencies. Masses are imported directly from load cases and load combinations. In this case, you have the option to consider the total mass, load components in the global Z-direction, or only the load component in the direction of gravity.
You can manually define additional masses at nodes, lines, members, or surfaces. Furthermore, you can influence the stiffness matrix by importing axial forces or stiffness modifications of a load case or load combination.
In RFEM, you can use these three powerful eigenvalue solvers:
- Root of Characteristic Polynomial
- Method by Lanczos
- Subspace Iteration
RSTAB, on the other hand, provides you with these two eigenvalue solvers:
- Subspace Iteration
- Shifted inverse power method
The selection of the eigenvalue solver depends primarily on your model size.
As soon as the program has completed the calculation, the eigenvalues, natural frequencies and periods are listed. These result windows are integrated in the main program RFEM/RSTAB. You can find all mode shapes of the structure in tables and also have an option to display them graphically and to animate them.
All result tables and graphics are part of the RFEM/RSTAB printout report. In this way, you can ensure clearly arranged documentation. You can also export the tables to MS Excel.
- Consideration and display of story masses
- Listing of structural elements and their information
- Automated creation of result sections on shear walls
- Output of section resultants in global direction for determining shear forces
- Optional definition of rigid diaphragm by story (story modeling)
- Stiffness type Floor Slab - Rigid Diaphragm
- Defining floor sets,
- for example, calculation of slabs as a 2D position within the 3D model
- Shear walls: Automatic definition of result members with any cross-section
- Design of rectangular cross-sections using the Concrete Design add-on
- Definition of deep beams
- Design with the Concrete Design add-on
- Tabular output of story actions, interstory drift, and center points of mass and stiffness, as well as the forces in shear walls
- Separate result display of the floor and stiffening design
- Optional neglecting of openings of a certain size
You have two options for a building model. You can create it when you start modeling the structure, or activate it afterwards. In the building model, you can then directly define the stories and manipulate them.
When manipulating the stories, you can choose whether to modify or retain the included structural elements using various options.
RFEM does some of the work for you. For example, it automatically generates result sections, so you don't need to perform a lot of calculations.
You can display the results as usual via the Results navigator. Furthermore, the dialog box of the add-on shows you the information about the individual floors. Thus, you always have a good overview.
Have you activated the Time-Dependent Analysis (TDA) add-on? Very well, now you can add time data to load cases. After you have defined the start and end of the load, the influence of creep at the end of the load is taken into account. The program allows you to model creep effects for frame and truss structures made of reinforced concrete.
In this case, the calculation is performed nonlinearly according to the rheological model (Kelvin and Maxwell model).
Was the calculation successful? You can now display the determined internal forces in tables and graphics, and consider them in the design.
- Artificial intelligence technology (AI): Particle swarm optimization (PSO)
- Structure optimization according to the minimum weight or deformation
- Use of any number of optimization parameters
- Specification of variable ranges
- Optimization of cross-sections and materials
- Parameter definition types
- Optimization | Ascending or Optimization | Descending
- Application of parametric models and blocks
- Code-based JavaScript parametrization of blocks
- Optimization taking into account the design results
- Tabular display of the best model mutations
- Real-time display of the model mutations in the optimization process
- Model cost estimation by specifying unit prices
- Determination of the global warming potential GWP when realizing the model by estimating the CO2 equivalent
- Specification of weight-, volume-, and area-based units (price and CO2e)
Did you know? The structural optimization in the programs RFEM and RSTAB is a completion of the parametric input. It is a parallel process beside the actual model calculation with all its regular calculation and design definitions. The add-on assumes that your model or block is built with a parametric context and is controlled in its entirety by global control parameters of the "optimization" type. Therefore, these control parameters have a lower and upper limit and a step size to delimit the optimization range. If you want to find optimal values for the control parameters, you have to specify an optimization criterion (for example, minimum weight) with the selection of an optimization method (for example, particle swarm optimization).
You can already find the cost and CO2 emission estimation in the material definitions. You can activate both options individually in each material definition. The estimation is based on a unit for unit cost or unit emission for members, surfaces, and solids. In this case, you can select whether to specify the units by weight, volume, or area.
There are two methods that you can use for the optimization process, with which you can find optimal parameter values according to a weight or deformation criterion.
The most efficient method with the littlest calculation time is the near-natural particle swarm optimization (PSO). Have you heard or read about it? This artificial intelligence (AI) technology has a strong analogy to the behavior of flocks of animals, looking for a resting place. In such swarms, you can find many individuals (cf. optimization solution - for example, weight) who like to stay in a group and follow the group movement. Let's assume that each individual swarm member has a need to rest at an optimal resting place (cf. best solution - for example, lowest weight). This need increases as the resting place is approached. Thus, the swarm behavior is also influenced by the properties of the space (cf. result diagram).
Why the excursion into biology? Quite simply – the PSO process in RFEM or RSTAB proceeds in a similar way. The calculation run starts with an optimization result from a random assignment of the parameters to be optimized. It repeatedly determines new optimization results with varied parameter values, which are based on the experience of the previously performed model mutations. The process continues until the specified number of possible model mutations is reached.
As an alternative to this method, the program also offers you a batch processing method. This method attempts to check all possible model mutations by randomly specifying the values for the optimization parameters until a predetermined number of possible model mutations is reached.
After calculating a model mutation, both variants also check the respective activated design results of the add-ons. Furthermore, they save the variant with the corresponding optimization result and value assignment of the optimization parameters if the utilization is < 1.
You can determine the estimated total costs and emission from the respective sums of the individual materials. The sums of the materials are composed of the weight-based, volume-based, and area-based partial sums of the member, surface, and solid elements.
- Stress determination using an elastic-plastic material model
- Design of masonry disc structures for compression and shear on the building model or single model
- Automatic determination of stiffness of a wall-slab hinge
- An extensive material database for almost all stone-mortar combinations available on the Austrian market (the product range is continuously being expanded, for other countries as well)
- Automatic determination of material values according to Eurocode 6 (ÖN EN 1996‑X)
- Option to create pushover analysis
You enter and model the structure directly in RFEM. You can combine the masonry material model with all common RFEM add-ons. This enables you to design the entire building models in connection with masonry.
The program automatically determines for you all parameters required for the calculation by using the material data that you have entered. Then, it finally generates the stress-strain curves for each FE element.
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.
Both optimization methods have one thing in common. At the end of the process, they provide you with a list of model mutations from the stored data. Here you can find the details of the controlling optimization result and the associated value assignment of the optimization parameters. This list is organized in descending order. You can find the assumed best solution shown in the first line. For this, the optimization result with its determined value assignment is closest to the optimization criterion. All add-on results have a utilization < 1. Furthermore, once the analysis is completed, the program will adjust the value assignment to that of the optimal solution for the optimization parameters in the global parameter list.
In the material dialog boxes, you can find the additional tabs "Cost Estimation" and "Estimation of CO2 Emissions". They show you the individual estimated sums of the assigned members, surfaces, and solids per unit weight, volume, and area. Furthermore, these tabs show the total cost and emission of all assigned materials. This gives you a good overview of your project.
Compared to the RF‑/DYNAM Pro - Natural Vibrations add-on module (RFEM 5 / RSTAB 8), the following new features have been added to the Modal Analysis add-on for RFEM 6 / RSTAB 9:
- Preset combination coefficients for various standards (EC 8, ASCE, and so on)
- Optional neglect of masses (for example, mass of foundations)
- Methods for determining the number of mode shapes (user-defined, automatic - to reach effective modal mass factors, automatic - to reach the maximum natural frequency)
- Output of modal masses, effective modal masses, modal mass factors, and participation factors
- Masses in mesh points displayed in tables and graphics
- Various scaling options for mode shapes in the Result navigator
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)
For each load case, the deformations can be displayed at the end time.
These results are also documented for you in the printout report of RFEM and RSTAB. You can select the report contents and extent specifically for the individual design checks.
Are you afraid that your project will end in the digital tower of Babel? The Building Model add-on for RFEM supports you in your work on a construction project with several stories. It allows you to define a building by means of stories at specified elevations. You can adjust the stories in many ways afterwards and also select the story slab stiffness. Information about the stories and the entire model (center of gravity, center of rigidity) is displayed for you in tables and graphics.
Building stone on stone has a long tradition in construction. The Masonry Design add-on for RFEM allows you to design masonry using the finite element method. It was developed as part of the research project DDMaS - Digitizing the Design of Masonry Structures. Here, the material model represents the nonlinear behavior of the brick-mortar combination in the form of macro-modeling. Do you want to find out more?
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.
Do you have great respect for the ravages of time? After all, it eventually gnaws at your construction projects. Use the Time-Dependent Analysis (TDA) add-on to consider the time-dependent material behavior of members. Long-term effects, such as creep, shrinkage, and aging, can influence the distribution of internal forces, depending on the structure. Prepare for this optimally with this add-on.
- Calculation of deflections and comparison with the normative or manually adjusted limit values
- Consideration of a precamber for the deflection analysis
- Different limit values are possible, depending on the design situation type
- Manual adjustment of reference lengths and segmentation by direction
- Calculation of deflections related to the initial structure or to the deformed structure
- Automatic consideration of time-dependent deformations by increasing the load with the creep factor (can also be user-defined on the stiffness side)
- Simplified vibration design
- Graphical result display integrated in RFEM/RSTAB; for example, the design ratio of a limit value, the deformation, or the sag
- Complete integration of the results into the RFEM/RSTAB printout report
Your RFEM/RSTAB program is responsible for generating and calculating the load and result combinations required for the serviceability limit state. Select the design situations for the deflection analysis in the Timber Design add-on. The calculated deformation values are then determined at each location of a member, depending on the specified precamber and the reference system, and then compared to the limit values.
You can specify the deformation limit value individually for each structural component in Serviceability Configuration. In this case, the maximum deformation should not exceed the permissible limit value, depending on the reference length. When defining design supports, you can segment the components. This allows you to determine the corresponding reference length automatically for each design direction.
Based on the position of the assigned design supports, the program automatically determines the difference between beams and cantilevers. Thus, you can be sure that the limit value is determined accordingly.
You find the serviceability limit state design fully integrated in the result tables of the Timber Design add-on. If yuo want to check the design results, you can open the program and display the results with all the details at each location of the designed members. Furthermore, graphics are available for you with the result diagrams of the design ratios.
A special thing is that All result tables and graphics can be integrated into the global printout report of RFEM/RSTAB as a part of the timber design results. You can also display and document the deformations of the entire structure as a part of the RFEM/RSTAB functionality. This function is independent of the add-on.
- A wide range of cross-sections, such as rectangular sections, square sections, T‑sections, circular sections, built-up cross-sections, irregular parametric cross-sections, and many others (suitability for design depends on the selected standard)
- Design of cross-laminated timber (CLT)
- Design of timber-based materials and laminated veneer lumber according to EC 5
- Design of tapered and curved members (design method according to the standard)
- Adjustment of the essential design factors and standard parameters is possible
- Flexibility due to detailed setting options for basis and extent of calculations
- Fast and clear results output for an immediate overview of the result distribution after the design
- Detailed output of the design results and essential formulas (comprehensible and verifiable result path)
- Numerical results clearly arranged in tables and graphical display of the results in the model
- Integration of the output into the RFEM/RSTAB printout report
- 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 (see the Product Feature)
- 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 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)
- Arbitrary definition of the charring time
- Option to calculate with or without adhesion of the layer for surface structures (cross-laminated timber)
- Free user-defined specification of the fire parameters
- Consideration of Different Effective Lengths in Fire Resistance Design
- Optional design "Compression perpendicular to grain"
- Graphical result display integrated in RFEM/RSTAB, such as a design ratio
- Complete integration of the results into the RFEM/RSTAB printout report
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.