The wind load of rectangular rounded structural components is a complex matter. The equivalent forces from wind load depend on the strength of the circulating wind load and the component geometry.
Structures are naturally three-dimensional. However, because it was impossible to perform calculations on three-dimensional models easily in the past, the structures were simplified and broken down into planar subsystems. With the increasing performance of computers and related software, it is often possible to do without these simplifications. Digital trends such as Building Information Modeling (BIM) and new options for creating realistic visualized models reinforce this trend. But do 3D models really offer an advantage, or are we just following a trend? The following text presents some arguments for working in 3D models.
When calculating regular structures, data input is often not complicated but time-consuming. Input automation can save valuable time. The task described in the present article is to consider the stories of a house as single construction stages. Data is entered using a C# program so that the user does not have to enter the elements of the individual floors manually.
If, after defining the generated loads belonging together, you switch to the visibility mode, the loads are also shown on the hidden structural elements.
The transparency intensity of various graphic elements in the Solid Transparent Display Mode can be edited individually in the Program Options dialog box under the Graphic tab to improve the overview.
For recurring elements such as certain structural components or standard parts, you can use the parametrization of a basic model. In the program, the main elements do not represent components but the corresponding node and therefore, they have to be parameterized. For example, a member is not defined by the length, but by the start and end nodes. In this way of modeling, complex formulas may occur especially in the case of three-dimensional structures.
Using the RF-TIMBER CSA module, timber column design is possible according to the CSA O86-19 standard. Accurately calculating timber member compressive resistance and adjustment factors is important for safety considerations and design. The following article will verify the factored compressive resistance in the RFEM add-on module RF-TIMBER CSA, using step-by-step analytical equations as per the CSA O86-19 standard including the column modification factors, factored compressive resistance, and final design ratio.
Using the RF-TIMBER CSA module, timber beam design is possible according to the CSA O86-14 standard. Accurately calculating timber member bending resistance and adjustment factors is important for safety considerations and design. The following article will verify the factored bending moment resistance in the RFEM add-on module RF-TIMBER CSA using step-by-step analytical equations as per the CSA O86-14 standard including the bending modification factors, factored bending moment resistance, and final design ratio.
The Master's Thesis of Tamás Drávai, Haroon Khalyar, and Gábor Nagy deals with the effect of interoperability between Computer Aided Design (CAD) and Finite Element Modeling (FEM) software on structural modeling and analysis. Several case studies were conducted, where a building information model was transferred from CAD to FEM software with different data exchange formats.
Buckling analysis according to the effective width method or the reduced stress method is based on the determination of the system critical load, hereinafter called LBA (linear buckling analysis). This article explains the analytical calculation of the critical load factor as well as utilization of the finite element method (FEM).
RF-PUNCH Pro performs punching shear design on concentrated load application locations (column connection, nodal support, and nodal load) as well as on wall ends and wall corners.
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 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 the "Edit Surface" dialog box, there is a new tab titled "Modify Stiffness" for the "Standard" and "Without Tension" surface types. Here, you can modify the elements of a stiffness matrix by defining the factors in the same way as in the case of orthotropic surfaces.
When calculating a surface model, the internal forces are determined separately for each finite element. Since the element-by-element results usually represent a discontinuous distribution, RFEM performs smoothing of the internal forces that takes into account the influence of adjacent elements. The discontinuous distribution of internal forces is adjusted with this method. The result evaluation is thus clearer and easier.
Singularities occur in a limited area due to the concentration of the stress-dependent result values. They are conditioned by the FEA methodology. In theory, the stiffness and/or the stress in an infinite size concentrate on an infinitesimally small area.
With the most recent ACI 318-19 standard, the long-term relationship to determine the concrete shear resistance, Vc, is redefined. With the new method, the member height, the longitudinal reinforcement ratio, and the normal stress now influence the shear strength, Vc. This article describes the shear design updates, and the application is demonstrated with an example.
A modell check allows you to find overlapping members, among other things. However, this targeted selection could cause some minor problems. Therefore, there is a selection window now available, which appears when you click on one of the elements. This appears by clicking on one of the elements. Additional information helps you to select the correct member.
In RFEM and RSTAB, there are several ways to select a part of the structural model for further processing. The most frequently used selection option is definitely "selection using window". Depending on the size of the structure, the simultaneous selection of several areas of the structure using this option may be time-consuming, since the unwanted model parts are selected as well.