Creating a validation example for Computational Fluid Dynamics (CFD) is a critical step in ensuring the accuracy and reliability of simulation results. This process involves comparing the outcomes of CFD simulations with experimental or analytical data from real-world scenarios. The objective is to establish that the CFD model can faithfully replicate the physical phenomena it is intended to simulate. This guide outlines the essential steps in developing a validation example for CFD simulation, from selecting a suitable physical scenario to analyzing and comparing the results. By meticulously following these steps, engineers and researchers can enhance the credibility of their CFD models, paving the way for their effective application in diverse fields such as aerodynamics, aerospace, and environmental studies.
In this article, a lap joint of a ZL purlin on a monopitch roof is modeled and designed using the Steel Joints add-on, and compared with the load-bearing capacity table of the manufacturer.
The events of recent years remind us of the importance of earthquake engineering in seismic regions. For you as an engineer, the design of structures in earthquake-prone areas is a constant trade-off between economic efficiency – the financial possibilities – and structural safety. If a collapse is inevitable, engineers must estimate how it will affect the structure. This article aims to provide you with an option on how to perform this estimation.
Our webservice offers users the opportunity to communicate with RFEM 6 and RSTAB 9 using various programming languages. Dlubal's high-level functions (HLFs) allow you to expand and simplify the WebService's functionality. In line with RFEM 6 and RSTAB 9, using our WebService makes the engineer's work easier and faster. Check it out now! This tutorial shows you how to use the C# library by means of a simple example.
For the stability verification of members using the equivalent member method, it is necessary to define effective or lateral-torsional buckling lengths in order to determine a critical load for stability failure. In this article an RFEM 6-specific function is presented, by which you can assign an eccentricity to the nodal supports and thus influence the determination of the critical bending moment considered in the stability analysis.
Spreadsheet programs like MS EXCEL are very popular with engineers because they allow you to simply automatize your calculations and quickly output the results. Therefore, combining MS EXCEL used as a graphical interface with Dlubal's WebService API is an obvious choice. By using the free xlwings library for Python, you can control EXCEL, and read and write values. The functionality is described in the following, using an example.
The Steel Joist Institute (SJI) previously developed Virtual Joist tables to estimate the section properties for Open Web Steel Joists. These Virtual Joist sections are characterized as equivalent wide-flange beams which closely approximate the joist chord area, effective moment of inertia, and weight. Virtual Joists are also available in the RFEM and RSTAB cross-section database.
The recently introduced Webservices gives users the ability to communicate with RFEM 6 using their programming language of choice. This feature is enhanced with our High Level Functions (HLF) Library. The libraries are available for Python, JavaScript, and C#. This article looks at a practical use case of programming a 2D Truss Generator with Python. "Learning by doing," as the saying goes.
In accordance with Sect. 6.6.3.1.1 and Clause 10.14.1.2 of ACI 318-19 and CSA A23.3-19, respectively, RFEM effectively takes into consideration concrete member and surface stiffness reduction for various element types. Available selection types include cracked and uncracked walls, flat plates and slabs, beams, and columns. The multiplier factors available within the program are taken directly from Table 6.6.3.1.1(a) and Table 10.14.1.2.
The add-on modules for designing structural member components according to national, European, and international standards also show design results in addition to numerical output in tables graphically, as diagrams displayed on the framework.
With the "Info About Object..." function available in the menu under "Tools", you can display all the information about an object by placing the cursor on it in the graphical window.
The "4.0 Results - Summary" table displays the infinity norm at the end of the load case results. The norm is used to estimate the largest eigenvalue of a structure. The largest eigenvalue of a structure is estimated by numerical analysis, as accurate determination can be very time-consuming.
In RFEM, you can display the contact properties between two surfaces by means of contact solids. Among other things, you should ensure that both contact surfaces of a contact solid have the same integrated objects. Therefore, when modeling the contact surfaces, we recommend using the copy function in order to create the second contact surface.
In the age of BIM, data exchange between the various disciplines of structural engineering is becoming increasingly important. Since each software has its own specifications with regard to the description of cross-sections and materials, RFEM and RSTAB offer a conversion table (mapping file).
In RF‑/FOUNDATION Pro, the available reinforcing steel diameters can be adjusted by the user. The adjustment of the available rebar diameters works similarly to the same function in the RF‑/CONCRETE (Members) and RF‑/CONCRETE Columns add‑on modules.
The SHAPE‑THIN and SHAPE‑MASSIVE cross-section programs are suitable for determining the cross-section properties of common thin-walled or thick-walled sections. These cross-section properties are also available for further analyses in RSTAB and RFEM.
Once you have determined the final tendon geometry in RF‑TENDON, exporting the model to a CAD program can be useful. For this purpose, the module includes the option to export the file in the .dxf file format. You can select the export function by right-clicking the workspace. After selecting the DXF format and the storage location, additional settings can be made.
To simulate a support clearance in a connection between members, you can use the "Diagram" function for member hinges. To use this function, first define the relevant degree of freedom as release. Then, you can select the "Diagram" function from the drop‑down list.
RFEM and RSTAB offer many display options in the Display Navigator. They can be completely different, depending on their function. You often have to click several times to make certain changes. If you want to optimize your work, you can create user‑defined views. In these views, you can save all specified settings. The following example illustrates this principle.
Various tools for modeling are available in RFEM. The modeling functions allow you to represent complex structures quickly and efficiently in the program. The connection of two circles or arcs, for example, can be generated with the "Tangent to Circles or Arcs" function.
In RF-/STEEL EC3, you can optimize a cross-section automatically within the design. To do this, select the corresponding cross-section in Table 1.3 or define variable parameters for a welded cross-section.
For solids, there is another option for the FE mesh setting. You can arrange a layered FE mesh in addition to a holistic FE mesh refinement. For this option, you can perform a defined division of the solid with finite elements between two parallel surfaces. This option is particularly suitable for very large solid geometries with a low height.
When designing several members in one design case, it is sometimes difficult to recognize the governing design checks. To improve the overview and to display the relevant design checks in a compact way, you can use the filter options under the result tables. These are included in all design modules of steel, aluminum, and timber structures in RFEM and RSTAB.