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.
Everything is online. The same is true for the Dlubal licenses for RFEM 6, RSTAB 9, and RSECTION. This article contains information about using and managing online licenses, reserving licenses, checking the license validity, and moving authorizations between the licenses.
In order to be able to carry out a pushover analysis, it is necessary to transform the determined capacity curve into a simplified form. The N2 method is described in Eurocode EN 1998. This article should help to explain what a bilinearization according to the N2 method involves.
The Geotechnical Analysis add-on provides RFEM with additional specific soil material models that are able to suitably represent complex soil material behavior. This technical article is an introduction to show how the stress-dependent stiffness of soil material models can be determined.
In this article, a heavy cargo box is calculated according to the guidelines of the German Bundesverband Holzpackmittel (HPE). The load cases for Handling by Crane and Sea Transport are calculated.
Both the determination of natural vibrations and the response spectrum analysis are always performed on a linear system. If nonlinearities exist in the system, they are linearized and thus not taken into account. They are caused by, for example, tension members, nonlinear supports, or nonlinear hinges. This article shows how you can handle them in a dynamic analysis.
The response spectrum analysis is one of the most frequently used design methods in the case of earthquakes. This method has many advantages. The most important is the simplification: It simplifies the complexity of earthquakes so far that the design can be performed with reasonable effort. The disadvantage of this method is that a lot of information is lost due to this simplification. One way to moderate this disadvantage is to use the equivalent linear combination when combining the modal responses. This article explains this option by describing an example.
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.
The modal relevance factor is a result of the linear stability analysis and qualitatively describes the degree of participation of individual members in a specific mode shape.
To be able to evaluate the influence of local stability phenomena of slender structural components, RFEM 6 and RSTAB 9 provide you with the option of performing a linear critical load analysis on the cross-section level. The following article explains the basics of the calculation and the result interpretation.
When a concrete slab is set upon the top flange, its effect is like a lateral support (composite construction), preventing problems of torsional buckling stability. If there is a negative distribution of the bending moment, the bottom flange is subjected to compression and the top flange is under tension. If the lateral support given by the stiffness of the web is insufficient, the angle between the bottom flange and the web intersection line is variable in this case so that there is a possibility of distortional buckling for the bottom flange.
The goal of using the RFEM 6 and Blender with the Bullet Constraints Builder add-on is to obtain a graphical representation of the collapse of a model based on real data of physical properties. RFEM 6 serves as the source of geometry and data for the simulation. This is another example of why it is important to maintain our programs as so-called BIM Open, in order to achieve collaboration across software domains.
As you may already know, RFEM 6 offers you the possibility to consider material nonlinearities. This article explains how to determine internal forces in slabs modeled with nonlinear material.
The Nonlinear Material Behavior add-on enables the consideration of material nonlinearities in RFEM 6. This article provides an overview of the available nonlinear material models, which are available after activating the add-on in the model’s Base Data.
Nodal releases are special objects in RFEM 6 that allow structural decoupling of objects connected to a node. The release is controlled by the release type conditions, which may also have nonlinear properties. This article will show the definition of nodal releases in a practical example.
Line releases are special objects in RFEM 6 that allow structural decoupling of objects connected to a line. They are mostly used to decouple two surfaces that are not rigidly connected or transferring only compressive forces at the common boundary line. By defining a line release, a new line is generated at the same place which transfers only the locked degrees of freedom. This article will show the definition of line releases in a practical example.
Plastic hinges are imperative for the Pushover Analysis (POA) as a nonlinear static method for the seismic analysis of structures. In RFEM 6, plastic hinges can be defined as member hinges. This article will show you how to define plastic hinges with bilinear properties.
Windbreak structures are special types of fabric structures which protect the environment from harmful chemical particles, abate wind erosion, and help to maintain valuable sources. RFEM and RWIND are used for wind-structure analysis as one-way fluid-structure interaction (FSI).
This article demonstrates how to structural design windbreak structures using RFEM and RWIND.
The properties of the connection between a reinforced concrete slab and a masonry wall can be correctly considered in the modeling using a special line hinge that is available in RFEM 6. This article will show you how to define this type of hinge using a practical example.
This article will show you how to properly consider the connection between surfaces that touch each other on one line with the help of line hinges in RFEM 6.
In RFEM 6, it is possible to define line welds on lines between surfaces and calculate the weld stresses using the Stress-Strain Analysis add-on. This article will show you how to do it.
The optimal scenario in which punching shear design according to ACI 318-19 [1] or CSA A23.3:19 [2] should be utilized is when a slab is experiencing a high concentration of loading or reaction forces occurring at one single node. In RFEM 6, the node in which punching shear is an issue is referred to as a punching shear node. The causes of these high concentration of forces can be introduced by a column, concentrated force, or nodal support. Connecting walls can also cause these concentrated loads at wall ends, corners, and ends of line loads and supports.
You can model and analyze masonry structures in RFEM 6 with the Masonry Design add-on that employs the finite element method for the design. Complex masonry structures can be modeled, and static and dynamic analysis can be performed, given that a nonlinear material model is implemented in the program to display the load-bearing behavior of masonry and the different failure mechanisms. You can enter and model masonry structures directly in RFEM 6 and combine the masonry material model with all common RFEM add-ons. In other words, you can design entire building models in connection with masonry.
Defining the appropriate effective length is crucial in obtaining the correct member design capacity. For X-bracing that is connected at the center, engineers often wonder if the full end-to-end length of the member shall be used, or whether using half of the length to where the members are connected is sufficient. This article outlines the recommendations given by the AISC and provides an example on how to specify the effective length of the X-braces in RFEM.
The punching shear design, in line with EN 1992-1-1, should be performed for slabs with a concentrated load or reaction. The node where the design of punching shear resistance is performed (that is, where there is a punching problem) is called a node of punching shear. The concentrated load at these nodes can be introduced by columns, concentrated force, or nodal supports. The end of the linear load introduction on slabs is also regarded as a concentrated load and therefore, the shear resistance at wall ends, wall corners, and ends or corners of line loads and line supports should be controlled as well.
Complex structures are assemblies of structural elements with various properties. However, certain elements can have the same properties in terms of supports, nonlinearities, end modifications, hinges, and so on, as well as design (for example, effective lengths, design supports, reinforcement, service classes, section reductions, and so on). In RFEM 6, these elements can be grouped on the basis of their shared properties and thus can be considered together for both modeling and design.
The new RFEM software generation provides the option to perform stability design of tapered timber members in line with the equivalent member method. According to this method, the design can be performed if the guidelines of DIN 1052, Section E8.4.2 for variable cross-sections are met. In various technical literature, this method is also adopted for Eurocode 5. This article demonstrates how to use the equivalent member method for a tapered roof girder.
This article deals with rectilinear elements of which the cross-section is subjected to axial compressive force. The purpose of this article is to show how very many parameters defined in the Eurocodes for concrete column calculation are considered in the RFEM 5 structural analysis software.