This chapter describes special features that have to be considered when modeling a structure for the Building Model add-on.
Openings
In a building model, openings cannot be modeled as basic objects of the type 'Opening'. The following image shows such invalid modeling. In this case, it is impossible to output the internal forces for each wall section (see the chapter Results).
On the other hand, if the openings are modeled using surface segments, as shown in the following image, the internal forces can be output for each wall section.
Rigid Diaphragms
If a Rigid Diaphragm is used to connect the individual components in a story plane, the floor is no longer displayed with its real stiffness. For example, if you want to consider expansion joints, Isokorb, or similar, use a different floor modeling.
A rigid plane rigidly couples all components of a story in the floor plane. Therefore, this option is not suitable for flexibly connected components such as a timber frame structure or a masonry wall. In this case, select the floor stiffness --. You can then consider the flexible connection using the corresponding modeling, for example with line hinges.
When the floor stiffness is set to 'Rigid diaphragm', all components of a story – members, surfaces, and solids – in the plane of the upper point of the floor are connected with a rigid link. The connection is made in the center of gravity of the story. The governing criterion for this is thus the weight of the individual connected components. Therefore, a very heavy member on one side of a story shifts the center of gravity in the corresponding direction.
In the following model, there are relatively light timber members on one side of the second floor. This moves the center of gravity to the other side of the floor.
.png?mw=350&hash=c6c25b135ffd26af9cd48d77813d2ba5853f936c)
