The new developer version was prepared to test the new features around the built-in support for parameters in equations. Under Tools->Parameters, unitless parameters can be defined and later used in some equations. The equations with support for parameters are now enabled for reference points, materials, sections, constraints and loads. More will follow in the future. To add an equation start the entry field with equal sign “=”.
For example, a parameter
p = 10 can be defined in the Parameters editor. Then this parameter can be used in equations as:
The equations are solved using an open-source project, Ncalc. All functions supported by the Ncalc are shown on their web page: Ncalc - Functions | ncalc Tutorial
Later, the support for running parametric studies will be added.
Please try out new equation features and report possible bugs.
I forgot to mention one important drawback of parameter implementation. Since the material properties can now be defined using equations (strings), their values are stored a little differently in the internal data classes. The consequence is that conversion to a text representation, which is used inside the material library file, becomes unreadable (the idea of the material library was that the materials would be written in a text format to enable the user to add materials by hand; since the text representation became almost unreadable this advantage is now gone). So, instead of developing two ways of storing the material data, I decided to save materials in a binary way (another option is to use the .inp format but the .inp format can not save the information about the unit system used for material definition). For this reason, the old material library files will not be compatible with the PrePoMax version 1.4.1 and higher.
The simplest solution to transfer the materials from an old material library to a new material library is to:
- open the old PrePoMax and the old material library,
- copy all materials to an existing FE model,
- save the model in a .pmx file,
- open the .pmx file in the new PrePoMax version and
- copy the materials to the new library.