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 pushover analysis is managed by a newly introduced analysis type in the load combinations. Here, you have access to the selection of the horizontal load distribution and direction, the selection of a constant load, the selection of the desired response spectrum for the determination of the target displacement, and the pushover analysis settings tailored to the pushover analysis.
In the pushover analysis settings, you can modify the increment of the increasing horizontal load and specify the stopping condition for the analysis. Furthermore, it is possible to easily adjust the precision for the iterative determination of the target displacement.
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.
In the "Group of Imperfection Cases" imperfection case, you can enter several geometric imperfection cases. This allows you to carry out GMNIA analyses where several geometric imperfections have to be superimposed.
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).
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)
The design checks for the members you have selected are carried out taking into account the governing component temperature. You can perform the cross-section design checks and stability analyses according to EN 1993‑1‑2, Section 4.2.3, in the Steel Design add-on. All reduction factors and coefficients that are necessary are stored accordingly and are taken into account when determining the load-bearing capacity.
The effective lengths for the equivalent member design are taken directly from the strength entries. You don't need to enter them again.
In each design, perform the cross-section classification first. For the cross-sections of Class 4, the design is performed automatically according to EN 1993‑1‑2, Annex E.
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)
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)
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
Deformation analyses of reinforced concrete surfaces without or with cracks (state II) by applying the approximation method (for example, deformation analysis according to ACI 318-19, 24.3.2.5 or EN 1992‑1‑1, Cl. 7.4.3 )
Tension stiffening of concrete applied between cracks
Optional consideration of creep and shrinkage
Graphical representation of results integrated in RFEM, such as deformation or sag of a flat slab
Clear numerical result display in the detail dialog box
Complete integration of results in the RFEM printout report
Have you carried out the design successfully? The results of the deformation analysis are now listed in clearly arranged output tables or detailed dialog boxes with info text. The program shows you all intermediate values in a comprehensible manner. Graphical representation of design ratios and deformation in RFEM allows you for a quick overview of critical areas.
Due to the results output of the design checks with all intermediate results, you can follow the calculation to the smallest detail. The complete integration of results in the RFEM printout report ensures that you obtain verifiable structural design.
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
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)
Stability analyses for flexural buckling, torsional buckling, and flexural-torsional buckling under compression
Lateral-torsional buckling analysis of the structural components subjected to moment loading
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
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 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)
This feature helps you with the load application. You can have the required loading applied incrementally. This option is particularly suitable for your calculations according to the large deformation analysis. Furthermore, you can easily perform post‑critical analyses in RFEM.
In RFEM, it is possible to determine pushover curves (also called capacity curves) and export them to Excel.
With the RF-DYNAM Pro - Equivalent Loads add-on module, it is possible to generate load distribution automatically in accordance with a mode shape and export it as a load case to RFEM.
In order to facilitate the data input, surfaces, members, sets of members, materials, surface thicknesses, and cross-sections are preset. It is possible to select the elements graphically using the [Select] function. The program provides access to the global material and cross-section libraries.
Load cases, load combinations, and result combinations can be combined in various design cases.
The combination of surface and member elements and separate designs allows you to model and analyze only critical parts, such as frame joints, using surface elements. The other parts of the model can be designed using member analyses.
The form-finding function can be activated in the General Data dialog box, Options tab. Prestresses (or geometrical requirements for members) can be defined in the parameters for surfaces and members. The form‑finding process is performed by calculation of an RF‑FORM‑FINDING case.
Steps of the working sequence:
Creation of a model in RFEM (surfaces, beams, cables, supports, material definition, and so on)
Setting of required prestress for membranes and force or length/sag for members (for example, cable)
Optional consideration of other loads for the form-finding process in special form‑finding load cases (self‑weight, pressure, steel node weight, and so on)
Setting of loads and load combinations for further structural analyses
The nonlinear calculation is activated by selecting the design method of the serviceability limit state. You can individually select the analyses to be performed as well as the stress-strain diagrams for concrete and reinforcing steel. The iteration process can be influenced by these control parameters: convergence accuracy, maximum number of iterations, arrangement of layers over cross-section depth, and damping factor.
You can set the limit values in the serviceability limit state individually for each surface or surface group. Allowable limit values are defined by the maximum deformation, the maximum stresses, or the maximum crack widths. The definition of the maximum deformation requires additional specification as to whether the non-deformed or the deformed system should be used for the design.
RF-CONCRETE Members
The nonlinear calculation can be applied to the ultimate and the serviceability limit state designs. In addition, you can specify the concrete tensile strength or the tension stiffening between the cracks. The iteration process can be influenced by these control parameters: convergence accuracy, maximum number of iterations, and damping factor.
The cross-section resistance design analyzes tension and compression along the grain, bending, bending and tension/compression as well as the strength in shear due to shear force.
The design of structural components at risk of buckling or lateral buckling is performed according to the Equivalent Member Method and considers the systematic axial compression, bending with and without compression force as well as bending and tension. Deflection of inner spans and cantilevers is compared with the maximum allowable deflection.
Separate design cases allow a flexible analysis for selected members, sets of members, and actions, as well as for the individual stability analyses. such as stability analysis, load duration in case of fire, member slendernesses, and limit deflection can be adjusted as desired.
In RX-TIMBER Frame, the following calculation settings are available:
Design of ULS, SLS, and/or fire resistance Selection of designs to be performed
Determination of displaying support forces and deformations
Adjusting the recommended limit values for the deformation analyses
Free definition of parameters for the fire resistance design performed according to the simplified method
Increasing bending stiffnesses for flat‑ended bending strains
Separate design cases allow for a flexible analysis of specific actions as well as for individual stability analyses. You can define the design type to be performed in the Control Parameters window.
The loading can be applied incrementally. The increment option is especially useful for calculations according to the large deformation analysis. For members, you can consider shear deformations and apply internal forces to a deformed or undeformed structural system. In addition, RFEM allows you to perform post‑critical analyses.
In RX-TIMBER Glued-Laminated Beam, the following calculation settings are available:
Design of ULS, SLS, and/or fire resistance
Selection of designs to be performed
Determination of displaying support forces and deformations
Adjusting the recommended limit values for the deformation analyses
Definition of parameters for the fire resistance design performed according to the simplified method (optionally for F 30‑B, F 60‑B, F 90‑B, and user‑defined)
Determination of tilting moment for pinned support
The design analyzes tension and compression along the grain, bending, bending and tension or compression, and shear due to shear force with and without torsion. Designs proceed at the level of design stress values. The design of structural components at risk of buckling or lateral buckling is performed according to the Equivalent Member Method and considers the systematic axial compression, bending with and without compression force as well as bending and tension.
The deflection in the characteristic and quasi-permanent design situations is determined for inner spans and cantilevers. Separate design cases allow for a flexible analysis of specific actions as well as for individual stability analyses. You can define the design type to be performed in the Control Parameters window.
Member and surface models created in RFEM are analyzed at a particular point by applying a unit load with the previously defined load magnitude and direction. The module determines the way the unit load affects the internal forces at the inspected point.
This simulation is represented graphically by an influence line or influence surface resulting from the load magnitude of the force or moment at the inspected model point. The graphical representation can be used for further analyses or to check the behavior of the model.
The RF-INFLUENCE add-on module determines the influence lines and surfaces of models containing beams and surfaces.