Structures are three-dimensional in reality; however, they can be simplified and analyzed as 2D or 1D models. The model type has a crucial influence on how the structural components are stressed, and it should be defined prior to modeling and calculation.
In order to create a surface model with failing supports close to reality, an option called "Failure if contact perpendicular to surfaces failed" is available in RFEM 5 for contact solids under "Contact Parallel to Surfaces".
This example describes a definition of a planar surface by four nodes that have been imported and seem to lie in a common plane. In reality, they are not exactly in one plane due to (for example) a previous modeling error of a few millimeters. When trying to create a planar surface, the error message "Error in the surface definition! The nodes do not lie in a common plane." appears.
In practice, an engineer often faces the task of representing the support conditions as close to the reality as possible in order to be able to analyze the deformations and internal forces of the structure subjected to their influence and to enable construction that is as cost efficient as possible. RFEM and RSTAB provide numerous options for defining nonlinear nodal supports. This second part describes the options for creating a nonlinear support for a restraint and provides a simple example. For a better understanding, the result is always compared to a linearly defined support.
In practice, an engineer often faces the task of representing the support conditions as close to the reality as possible in order to be able to analyze the deformations and internal forces of the structure subjected to their influence and to enable construction that is as cost-effective as possible. RFEM and RSTAB provide numerous options for defining nonlinear nodal supports. The first section of my article describes the options for creating a nonlinear free support and provides a simple example. For a better understanding, the result is always compared to a linearly defined support.
In order to estimate the structural behavior of masonry close to reality by using RFEM, it is necessary to select a material and a material model first. Since masonry responds to tension by cracking, you have to select a nonlinear material model. This can be selected if the RF-MAT NL add-on module is available.