Compared to the RF‑/STEEL add-on module (RFEM 5 / RSTAB 8), the following new features have been added to the Stress-Strain Analysis add-on for RFEM 6 / RSTAB 9:
Treatment of members, surfaces, solids, welds (line welded joints between two and three surfaces with subsequent stress design)
Output of stresses, stress ratios, stress ranges, and strains
Limit stress depending on the assigned material or a user-defined input
Individual specification of the results to be calculated through freely assignable setting types
Non-modal result details with prepared formula display and additional result display on the cross-section level of members
RSECTION contains an extensive library of rolled sections, as well as parametric thin-walled and massive cross-sections. You can compose them or supplement them with new elements.
Graphical tools and functions allow you to model complex section shapes in the usual way common for CAD programs. The graphical input supports, among other things, the setting of arcs, circles, ellipses, parabolas, and NURBS. As an alternative, you can import a DXF file and use this as the basis for further modeling. You can easily model a section consisting of different materials with minimum effort.
Furthermore, a parameterized input allows you to enter the cross-section dimensions and internal forces in such a way that they depend on certain variables.
You can also carry out all inputs by means of a script.
After you have completed the design, the program takes care of clearly arranged results. Thus, the program shows you the resulting maximum stresses and stress ratios sorted by section, member/surface, solid, member set, x-location, and so on. In addition to the tabular result values, the add-on shows you the corresponding cross-section graphic with stress points, stress diagram, and values as well. You can relate the design ratio to any kind of stress type. The current location is highlighted in the RFEM/RSTAB model.
In addition to the tabular evaluation, the program offers you even more. You can also graphically check the stresses and design ratios on the RFEM/RSTAB model. It is possible for you to adjust the colors and values individually.
The display of result diagrams of a member or set of members enables you a targeted evaluation. For each design location, you can open the respective dialog box to check the design-relevant section properties and stress components of any stress point. Finally, you have the option of printing the corresponding graphic, including all design details.
After activating the RF‑PIPING add‑on module, a new toolbar is available in RFEM and the project navigator and tables are extended. The piping system is now modeled in the same way as the members. Pipe bends are defined simultaneously by tangents (straight pipe sections) and radius. Thus, it is easy to subsequently change bend parameters.
It is also possible to extend the piping subsequently by defining special components (expansion joints, valves, and others). The implemented libraries of structural components facilitate the definition.
Continuous pipe sections are defined as sets of piping systems. For piping loads, member loads are assigned to the respective load cases. The combination of loads is included in piping load combinations and result combinations. After the calculation, you can display deformations, member internal forces, and support forces graphically or in tables.
Pipe stress analysis according to standards can then be performed in the RF‑PIPING Design add‑on module. You only need to select the relevant sets of piping systems and load situations.
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.
After the calculation, the maximum stresses and stress ratios are displayed sorted by sections, members/surfaces, member sets, or x-locations. In addition to the tabular result values, the corresponding cross-section graphic with stress points, stress diagram, and values is displayed as well. The design ratio can be related to any kind of stress type. The current location is highlighted in the RFEM/RSTAB model.
In addition to the result evaluation in the module, it is possible to represent the stresses and stress ratios graphically in the RFEM/RSTAB work window. It is possible to individually adjust the colors and values.
Result diagrams of a member or set of members facilitate targeted evaluation. Furthermore, you can open the respective dialog box of each design location to check the design-relevant section properties and stress components of any stress point. It is possible to print the corresponding graphic, including all design details.
SHAPE-THIN calculates all relevant cross‑section properties, including plastic limit internal forces. Overlapping areas are set close to reality. If cross-sections consist of different materials, SHAPE‑THIN determines the effective cross‑section properties with respect to the reference material.
In addition to the elastic stress analysis, you can perform the plastic design including interaction of internal forces for any cross‑section shape. The plastic interaction design is carried out according to the Simplex Method. You can select the yield hypothesis according to Tresca or von Mises.
SHAPE-THIN performs a cross-section classification according to EN 1993-1-1 and EN 1999-1-1. For steel cross-sections of cross-section class 4, the program determines effective widths for unstiffened or stiffened buckling panels according to EN 1993-1-1 and EN 1993-1-5. For aluminum cross-sections of cross-section class 4, the program calculates effective thicknesses according to EN 1999-1-1.
Optionally, SHAPE‑THIN checks the limit c/t-values in compliance with the design methods el‑el, el‑pl, or pl‑pl according to DIN 18800. The c/t-zones of elements connected in the same direction are recognized automatically.
SHAPE-THIN includes an extensive library of rolled and parameterized cross-sections. They can be composed or supplemented by new elements. It is possible to model a section consisting of different materials.
Graphical tools and functions allow for modeling complex section shapes in the usual way common for CAD programs. The graphical entry provides the option of setting point elements, fillet welds, arcs, parameterized rectangular and circular sections, ellipses, elliptical arcs, parabolas, hyperbolas, spline, and NURBS. Alternatively, it is possible to import a DXF file that is used as the basis for further modeling. You can also use guidelines for modeling.
Furthermore, parameterized input allows you to enter model and load data in a specific way so they depend on certain variables.
Elements can be divided or attached to other objects graphically. SHAPE-THIN automatically divides the elements and provides for an uninterrupted shear flow by introducing dummy elements. In the case of dummy elements, you can define a specific thickness to control the shear transfer.
After modeling piping systems in RFEM using RF‑PIPING and defining loads as well as load and result combinations, you can carry out pipe stress analysis in the RF‑PIPING Design add‑on module.
You can select all or only some pipelines and loads, load or result combinations for piping design. The material library provides various materials according to EN 13480‑3, ASME B31.1‑2012, and ASME B31.3‑2012 standards.
After the calculation, the results are displayed in clearly arranged windows; for example, by cross‑section, by pipeline, or by members. You can also display the design ratio graphically on the entire model in RFEM. This way, you can quickly recognize critical or oversized areas of the cross-section.
In addition to the input and result data, including design details displayed in tables, you can add all graphics into the printout report. This way, comprehensible and clearly arranged documentation is guaranteed. You can select the report contents and extent specifically for the individual designs.
Graphical input of piping systems and piping components
Illustrative visualization of piping systems and piping components in RFEM graphic window
Comprehensive libraries for piping cross‑sections and materials
Comprehensive libraries for flanges, reducers, tees, and expansion joints
Consideration of piping structure (insulation, lining, tin‑plate)
Automatic calculation of stress intensification factors and flexibility factors
Specific piping action categories for load cases
Optional automatic combinatorics of load cases
Consideration of material properties (modulus of elasticity, coefficient of thermal expansion) either during operating temperature (default setting) or during reference (assembly) temperature of material
Consideration of strain and uplift due to pressure (Bourdon effect)
Interaction between the supporting structure and the piping system
All results can be evaluated and visualized in an appealing numerical and graphical form. Selection functions facilitate the targeted evaluation.
The printout report corresponds to the high standards of RFEM and -rstab RSTAB. Modifications are updated automatically. Furthermore, you can print the reduced report in a short form, including all relevant data and a user-defined cross-section graphic.
It is possible to freely model a cross-section using surfaces limited by polygonal lines, including openings and point areas (reinforcements). Alternatively, you can use the DXF interface to import the geometry. An extensive material library facilitates the modeling of composite cross-sections.
Definition of limit diameters and priorities allows for a curtailment of reinforcements. In addition, you can consider the respective concrete covers and prestresses.