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.
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.
Surfaces in building models can be of many different sizes and shapes. All surfaces can be considered in RFEM 6 because the program allows to define different materials and thicknesses as well as surfaces with different stiffness and geometry types. This article focuses on four of these surface types: rotated, trimmed, without thickness, and load transfer.
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.
This article shows how the “Time-Dependent Analysis” add-on is integrated in RFEM 6 and RSTAB 9. It describes how to define input data such as the time-dependent characteristics of the material, how to determine the type of analysis and how to specify loading times.
In RFEM 6 it is possible to define multilayer surface structures with the help of the “Multilayer Surfaces” add-on. Hence, if you have activated the add-on in the model’s Base Data, it is possible to define layer structures of any material model. You can also combine material models of, for example, isotropic and orthotropic materials.
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.
Steel has poor thermal properties in terms of fire resistance. The thermal expansion for increasing temperature is very high compared to that of other building materials, and might result in effects that were not present in the design at normal temperature due to restraint in the component. As temperature increases, steel ductility increases, whereas its strength decreases. Since steel loses 50% of its strength at temperature of 600 °C, it is important to protect components against fire effects. In the case of protected steel components, the fire resistance duration can be increased due to the improved heating behavior.
This article describes how a flat slab of a residential building is modeled in RFEM 6 and designed according to Eurocode 2. The plate is 24 cm thick and is supported by 45/45/300 cm columns at distances of 6.75 m in both the X and Y directions (Image 1). The columns are modeled as elastic nodal supports by determining the spring stiffness based on the boundary conditions (Image 2). C35/45 concrete and B 500 S (A) reinforcing steel are selected as the materials for the design.