It is necessary to design some structures in different configurations. It may be that an aerial work platform must be analyzed in its position on the ground as well as in the middle and in the extended position. Since such tasks require the creation of several models, which are almost identical, updating all the models with just one mouse click is a considerable relief.
If a rib is part of a nonlinear design or is rigidly connected to following walls, a surface should be used for the modeling instead of a member. So that the rib can still be designed as a member, a result member with the correct eccentricity is required, which transforms the surface internal forces into member internal forces.
If you read out the results of a surface by means of the COM interface, you get a one-dimensional field with all results at the FE nodes or grid points. To get the results on the edge of a surface or along a line within the surfaces, you have to filter out the results in the area of the line. The following article describes a function for this step.
When editing elements via the COM interface, selecting elements is often a problem because it cannot be carried out visually via the work window. The selection can be particularly difficult for models that have been created via the program interface and are then to be modified using a separate program. Apart from the exception, when the selection was made previously via RFEM, there are several alternatives for programming.
The parts lists give information about which and how many parts are necessary for creating a building. They form the basis for identifying the needs and purchasing the components. Parts lists can be created in design modules, such as RF‑/STEEL EC3, RF‑/TIMBER Pro, and so on. Furthermore, a customized parts list can be created with the RF-COM/RS-COM interface.
RFEM and RSTAB are able to cover a large number of branches in the building and construction industry with their generally usable structural frame analysis and FEM programs. Designing cable structures is thus also possible in both software solutions. Some assistance tools for modeling and design will be presented in the following text.
RF-COM/RS-COM is a programmable interface that allows the user to expand the main programs RFEM and RSTAB with customized input macros or post‑processing programs. A tool to copy and move selected guidelines in RFEM will be developed in this article. It is also possible to copy or move the guidelines to another work plane. VBA in Excel will be used as the programming environment.
Part 4.1 of this article series describes the connection of the RF‑/STEEL EC3 add‑on module; the members and load combinations to be designed were already defined. This section will focus on the optimization of cross‑sections in the module and the transfer to RFEM. The elements already explained in the previous parts are not described again.
Sections 4.1 and 4.2 of this article series describe the optimization of a frame using the RF‑/STEEL EC3 add-on module. The fifth section explains how to link the module and get the relevant members. The elements already explained in the previous sections will not be described again.
Part 2.2 of the article series about the COM interface describes creating and modifying nodal supports, loads, load cases, load combinations, and result combinations on an example of a member. The fourth part explains creating individual tools.
With RFEM 5.06 and RSTAB 8.06, the examples and help files for programming the COM interface are not only available on the Internet, they are also included in the installation. To find them, look for the "SDK" folder in the project directory (usually C:\Users\Public\Documents\Dlubal).
Part 2.1 of the article series about the COM interface described creating and modifying elements on an example of a member. In the third part, these core elements are used again to create nodal supports, loads, load combinations, and result combinations. Thus, the model created in the second part will be extended. Therefore, the elements explained in Part 1 and Part 2.1 are not described again.
The first part of the article series about the COM interface described opening and creating a model in RFEM. The second part explains creating and modifying elements on an example of a member. The elements described in Part 1 will not be explained again here.
The first part of the post about the COM interface describes opening and closing RFEM. VBA programming language is used in Excel; however, the program sequence is the same as for programming with C#. First, it is necessary to add the corresponding reference in VBA to recognize the commands for the interface. The image on the left shows an example of RFEM 5.