You can program your own user-defined material laws with the UMAT interface in GeoDict.

UMATs are a concept from the FEA software Abaqus, and the interface is compatible with GeoDict. This means that you can directly use your already existing user materials in GeoDict. To get familiar with the syntax, some UMAT files are delivered with GeoDict. UMATs are Fortran files (*.f or *.f90), but in GeoDict it is also possible to directly use the compiled files (*.so). Nevertheless, *.so files from GeoDict 2020 and before cannot be used in GeoDict 2021 and later, since the required compiler version changed. Additionally, they might be incompatible between different computers. Therefore, it is important to always keep the source files (*.f or *.f90).

However, if a material can be defined by using the internal material laws, then we recommend using those instead of UMATs, since they are deeper integrated into GeoDict and easier to set up.