.svg?mw=64&hash=343d71fbdf234f1411db2920f2dff33c0dbd6231)
Video | 3skeng Steelwork Tool
Online Manual RFEM | Surfaces
In June 2023, the roof of the amphitheater of the theater in Most was successfully completed. The membrane structure has been specially designed to provide protection from the sun and rain above the stage, while making the entire space a visual attraction. The author of the design is Carl Stahl & Co., the calculation was carried out using the programs RFEM 5 and RWIND 2.
Membrane roofing of the amphitheater
| Number of Nodes | 116 |
| Number of Lines | 43 |
| Number of Members | 33 |
| Number of Surfaces | 6 |
| Number of Load Cases | 2 |
| Total Weight | 6.390 tons |
| Dimensions | 87.22 x 68.9 x 36.87 feet |
| Program Version | 5.29.01 |
The Ponding load type allows you to simulate rain actions on multi-curved surfaces, taking into account the displacements according to the large deformation analysis.
This numerical rainfall process examines the assigned surface geometry and determines which rainfall portions drain away and which rainfall portions accumulate in puddles (water pockets) on the surface. The puddle size then results in a corresponding vertical load for the structural analysis.
For example, you can use this feature in the analysis of approximately horizontal membrane roof geometries subjected to rain loading.
Go to Explanatory Video
Compared to the RF-FORM-FINDING add-on module (RFEM 5), the following new features have been added to the Form-Finding add-on for RFEM 6:
- Specification of all form-finding load boundary conditions in one load case
- Storage of form-finding results as initial state for further model analysis
- Automatic assignment of the form-finding initial state via combination wizards to all load situations of a design situation
- Additional form-finding geometry boundary conditions for members (unstressed length, maximum vertical sag, low-point vertical sag)
- Additional form-finding load boundary conditions for members (maximum force in member, minimum force in member, horizontal tension component, tension at i-end, tension at j-end, minimum tension at i-end, minimum tension at j-end)
- Material types "Fabric" and "Foil" in material library
- Parallel form-findings in one model
- Simulation of sequentially building form-finding states in connection with the Construction Stages Analysis (CSA) add-on
Once you activate the Form-Finding add-on in the Base Data, a form-finding effect is assigned to the load cases with the load case category "Prestress" in conjunction with the form-finding loads from the member, surface, and solid load catalog. This is a prestress load case. It thus mutates into a form-finding analysis for the entire model with all member, surface, and solid elements defined in it. You reach the form-finding of the relevant member and membrane elements amid the overall model by using special form-finding loads and regular load definitions. These form-finding loads describe the expected state of deformation or force after the form-finding in the elements. The regular loads describe the external loading of the entire system.
Do you know exactly how the form-finding is performed? First, the form-finding process of the load cases with the load case category "Prestress" shifts the initial mesh geometry to an optimally balanced position by means of iterative calculation loops. For this task, the program uses the Updated Reference Strategy (URS) method by Prof. Bletzinger and Prof. Ramm. This technology is characterized by equilibrium shapes that, after the calculation, comply almost exactly with the initially specified form-finding boundary conditions (sag, force, and prestress).
In addition to the pure description of the expected forces or sags on the elements to be formed, the integral approach of the URS also enables a consideration of regular forces. In the overall process, this allows, for example, for a description of the self-weight or a pneumatic pressure by means of corresponding element loads.
All these options give the calculation kernel the potential to calculate anticlastic and synclastic forms that are in an equilibrium of forces for planar or rotationally symmetric geometries. In order to be able to realistically implement both types individually or together in one environment, the calculation provide you with two ways to describe the form-finding force vectors:
- Tension method - description of the form-finding force vectors in space for planar geometries
- Projection method - description of the form-finding force vectors on a projection plane with fixation of the horizontal position for conical geometries
.png?mw=350&hash=e3f5898d72f463e9b3e774659aabcb220466c522)
.jpg?mw=350&hash=196d91410dd36f58fcc8b0194f4577bb70cf53c3)
Main Program
The new generation of 3D FEA software is used for the structural analysis of members, surfaces, and solids.
Add-On
The Form-Finding add-on finds the optimal shape of members subjected to axial forces and tension-loaded surface models. The shape is determined by the equilibrium between the member axial force or the membrane stress and the existing boundary conditions.
Main Program
Structural engineering software for a finite element analysis (FEA) of planar and spatial structural systems consisting of plates, walls, shells, members (beams), solids, and contact elements
Add-On Module
Form-finding of tensile membrane and cable structures
Add-On Module
Generation of cutting patterns for tensile membrane structures
Add-On
The Nonlinear Material Behavior add-on allows you to consider material nonlinearities in RFEM for example, isotropic plastic, orthotropic plastic, isotropic damage).
Add-On
The Structure Stability add-on performs stability analysis of structures. It determines critical load factors and the corresponding stability modes.
Add-On
The Torsional Warping (7 DOF) add-on allows you to consider cross-section warping as an additional degree of freedom when calculating members.
Add-On
The Multilayer Surfaces add-on allows you to define multilayer surface structures. The calculation can be carried out with or without the shear coupling.
Add-On
The two-part Optimization & Costs / CO2 Emission Estimation add-on finds suitable parameters for parameterized models and blocks via the artificial intelligence (AI) technique of particle swarm optimization (PSO) for compliance with common optimization criteria. Furthermore, this add-on estimates the model costs or CO2 emissions by specifying unit costs or emissions per material definition for the structural model.
Add-On
The Stress-Strain Analysis add-on performs general stress analysis by calculating the existing stresses and comparing them with the limit stresses.
Add-On
The Concrete Design add-on allows for various design checks according to international standards. You can design members, surfaces, and columns, as well as perform punching and deformation analyses.
Add-On
The Steel Design add-on performs the ultimate and serviceability limit state design checks of steel members according to various standards.
Add-On
The Timber Design add-on performs the ultimate, serviceability, and fire resistance limit state design checks of timber members according to various standards.
Add-On
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 titled DDMaS – Digitizing the Design of Masonry Structures. The material model represents the nonlinear behavior of the brick-mortar combination in the form of macro-modeling.
Add-On
The Aluminum Design add-on performs the ultimate and serviceability limit state design checks of aluminum members according to various standards.
.png?mw=600&hash=49b6a289915d28aa461360f7308b092631b1446e)
Add-On
The Steel Joints add-on for RFEM allows you to analyze steel connections using an FE model. The FE model is generated automatically in the background and can be controlled via the simple and familiar input of components.
Main Program
The modern 3D structural analysis and design program is suitable for the structural and dynamic analysis of beam structures as well as the design of concrete, steel, timber, and other materials.
Add-On
The Structure Stability add-on performs the stability analysis of structures. It determines critical load factors and the corresponding stability modes.
Add-On
The Torsional Warping (7 DOF) add-on allows for considering cross-section warping as an additional degree of freedom when calculating members.
Add-On
The two-part Optimization & Costs / CO2 Emission Estimation add-on finds suitable parameters for parameterized models and blocks via the artificial intelligence (AI) technique of particle swarm optimization (PSO) for compliance with common optimization criteria. Furthermore, this add-on estimates the model costs or CO2 emissions by specifying unit costs or emissions per material definition for the structural model.
Add-On
The Stress-Strain Analysis add-on performs a general stress analysis by calculating the existing stresses and comparing them to the limit stresses.
Add-On
Concrete Design add-on allows for various design checks of members and columns according to international standards.
Add-On
The Steel Design add-on performs the ultimate and serviceability limit state design checks of steel members according to various standards.
Add-On
The Timber Design add-on performs the ultimate, serviceability, and fire resistance limit state design checks of timber members according to various standards.
Add-On
The Aluminum Design add-on performs the ultimate and serviceability limit state design checks of aluminum members according to various standards.